null-safety

.vscode/launch.json

@@ -11,12 +11,12 @@
             "type": "dart"
         },
         {
-            "program": "test/template_test/.dart_tool/build/entrypoint/build.dart",
-            "name": "template_test",
-            "cwd": "template_test",
+
+            "name": "Test",
+            "program": "test/template_test/bin/service.dart",
             "request": "launch",
-            "type": "dart",
-            "args": ["serve"],
+            "type": "dart"
+
         }
     ]
 }

lib/builder.dart

@@ -9,7 +9,7 @@ import 'package:yaml/yaml.dart';
 class TemplateBuilder implements Builder {
   //BuilderOptions options;
   String _fileName;
-  TemplateBuilder([BuilderOptions options]) : _fileName = _get_dest(options);
+  TemplateBuilder([BuilderOptions? options]) : _fileName = _get_dest(options);
 
   @override
   Future build(BuildStep buildStep) async {
@@ -21,7 +21,7 @@ class TemplateBuilder implements Builder {
     await buildStep.writeAsString(id, content);
   }
 
-  static String _get_dest(BuilderOptions options) {
+  static String _get_dest(BuilderOptions? options) {
     const defaultDestination = 'lib/src/iip_template.dart';
     if (options == null) return defaultDestination;
     if (options.config == null) return defaultDestination;

lib/src/Core/AsyncBag.dart

@@ -1,55 +1,62 @@
 import 'AsyncReply.dart';
 import '../Resource/Warehouse.dart';
 
+// class ReplyIndex<T> {
+//   int index;
+//   AsyncReply<T> reply;
+//   T
+// }
 
 class AsyncBag<T> extends AsyncReply<List<T>> {
   List<AsyncReply<T>> _replies = <AsyncReply<T>>[];
-  List<T> _results = <T>[];
+
+  //List<T?> _results = <T>[];
 
   int _count = 0;
   bool _sealedBag = false;
 
-  Type arrayType;
+  Type? arrayType;
 
   seal() {
     //print("SEALED");
 
     if (_sealedBag) return;
-
     _sealedBag = true;
 
-    if (_results.length == 0) trigger(<T>[]);
+    if (_replies.length == 0) trigger(<T>[]);
 
-    for (var i = 0; i < _results.length; i++) {
+    var results = List<T?>.filled(_replies.length, null);
+
+    for (var i = 0; i < _replies.length; i++) {
       var k = _replies[i];
       var index = i;
 
-      k.then<dynamic>((r) {
-        _results[index] = r;
+      k..then((r) {
+        results[index] = r;
         _count++;
-        if (_count == _results.length) {
+        if (_count == _replies.length) {
           if (arrayType != null) {
-            var ar = Warehouse.createArray(arrayType);
-            _results.forEach(ar.add);
-            trigger(ar);
+            var ar = Warehouse.createArray(arrayType as Type);
+            results.forEach(ar.add);
+            trigger(ar as List<T>);
           } else {
-            trigger(_results);
+            trigger(results.cast<T>());
           }
         }
-      }).error((ex) {
+      })..error((ex) {
         triggerError(ex);
       });
     }
   }
 
-  add(AsyncReply<T> reply) {
+  void add(AsyncReply<T> reply) {
     if (!_sealedBag) {
-      _results.add(null);
+      //_results.add(null);
       _replies.add(reply);
     }
   }
 
-  addBag(AsyncBag<T> bag) {
+  void addBag(AsyncBag<T> bag) {
     bag._replies.forEach((r) {
       add(r);
     });

lib/src/Core/AsyncException.dart

@@ -4,7 +4,7 @@ import 'ErrorType.dart';
 class AsyncException implements Exception {
   final ErrorType type;
   final int code;
-  final String message;
+  final String? message;
 
   AsyncException(this.type, this.code, this.message) {}
 
@@ -20,7 +20,7 @@ class AsyncException implements Exception {
           ": " +
           (message ?? "");
     else
-      return code.toString() + ": " + message;
+      return code.toString() + ": " + (message ?? '');
   }
 
   @override

lib/src/Core/AsyncQueue.dart

@@ -2,8 +2,8 @@ library esiur;
 
 import 'AsyncReply.dart';
 
-class AsyncQueue<T> extends AsyncReply<T> {
-  List<AsyncReply<T>> _list = <AsyncReply<T>>[];
+class AsyncQueue<T> extends AsyncReply<T?> {
+  List<AsyncReply<T?>> _list = <AsyncReply<T?>>[];
 
 //      object queueLock = new object();
 
@@ -23,7 +23,7 @@ class AsyncQueue<T> extends AsyncReply<T> {
     processQueue(null);
   }
 
-  void processQueue(T o) {
+  void processQueue(T? o) {
     //lock (queueLock)
     for (var i = 0; i < _list.length; i++)
       if (_list[i].ready) {

lib/src/Core/AsyncReply.dart

@@ -29,9 +29,9 @@ import 'ProgressType.dart';
 class AsyncReply<T> implements Future<T> {
   List<Function(T)> _callbacks = <Function(T)>[];
 
-  T _result;
+  late T _result;
 
-  List<Function(AsyncException)> _errorCallbacks = <Function(AsyncException)>[];
+  List<Function> _errorCallbacks = <Function>[];
 
   List<Function(ProgressType, int, int)> _progressCallbacks =
       <Function(ProgressType, int, int)>[];
@@ -39,7 +39,7 @@ class AsyncReply<T> implements Future<T> {
   List<Function(T)> _chunkCallbacks = <Function(T)>[];
 
   bool _resultReady = false;
-  AsyncException _exception;
+  AsyncException? _exception;
 
   bool get ready {
     return _resultReady;
@@ -49,7 +49,7 @@ class AsyncReply<T> implements Future<T> {
     _resultReady = value;
   }
 
-  T get result {
+  T? get result {
     return _result;
   }
 
@@ -62,26 +62,20 @@ class AsyncReply<T> implements Future<T> {
     return this;
   }
 
-  AsyncReply<R> then<R>(FutureOr<R> onValue(T value), {Function onError}) {
+  AsyncReply<R> then<R>(FutureOr<R> onValue(T value), {Function? onError}) {
     _callbacks.add(onValue);
+
     if (onError != null) {
-      if (onError is Function(dynamic, dynamic)) {
-        _errorCallbacks.add((ex) => onError(ex, null));
-      } else if (onError is Function(dynamic)) {
       _errorCallbacks.add(onError);
-      } else if (onError is Function()) {
-        _errorCallbacks.add((ex) => onError());
-      } else if (onError is Function(Object, StackTrace)) {
-        _errorCallbacks.add((ex) => onError(ex, null));
-      }
     }
 
-    if (_resultReady) onValue(result);
+    if (_resultReady) onValue(result as T);
 
-    if (R == Null)
-      return null;
-    else
-      return this as AsyncReply<R>;
+//    if (R == Null)
+    //    return null;
+    //else
+    //if (R == T)
+     return AsyncReply<R>();
   }
 
   AsyncReply<T> whenComplete(FutureOr action()) {
@@ -90,21 +84,39 @@ class AsyncReply<T> implements Future<T> {
   }
 
   Stream<T> asStream() {
-    return null;
+    return Stream.empty();
+    //return null;
   }
 
-  AsyncReply<T> catchError(Function onError, {bool test(Object error)}) {
-    return this.error(onError);
+//  Future<T> catchError(Function onError, {bool test(Object error)?});
+
+  AsyncReply<T> catchError(Function onError, {bool test(Object error)?}) {
+    ///return this.error(onError);
+
+    _errorCallbacks.add(onError);
+
+    if (_exception != null) {
+      if (onError is Function(dynamic, dynamic)) {
+        onError(_exception, null);
+      } else if (onError is Function(dynamic)) {
+        onError(_exception);
+      } else if (onError is Function()) {
+        onError();
+      } else if (onError is Function(Object, StackTrace)) {
+        onError(_exception as Object, StackTrace.current);
+      }
     }
 
-  AsyncReply<T> timeout(Duration timeLimit, {FutureOr<T> onTimeout()}) {
     return this;
   }
 
-  AsyncReply<T> error(Function(dynamic) callback) {
-    _errorCallbacks.add(callback);
+  AsyncReply<T> timeout(Duration timeLimit, {FutureOr<T?> onTimeout()?}) {
+    return this;
+  }
 
-    if (_exception != null) callback(_exception);
+  AsyncReply<T> error(callback(AsyncException ex)) {
+    _errorCallbacks.add(callback);
+    if (_exception != null) callback(_exception as AsyncException);
 
     return this;
   }
@@ -144,10 +156,19 @@ class AsyncReply<T> implements Future<T> {
     //{
 
     if (this._errorCallbacks.length == 0)
-      throw _exception;
+      throw _exception as AsyncException;
     else
       _errorCallbacks.forEach((x) {
+        if (x is Function(dynamic, dynamic)) {
+          x(_exception, null);
+        } else if (x is Function(dynamic)) {
           x(_exception);
+        } else if (x is Function()) {
+          x();
+        } else if (x is Function(Object, StackTrace)) {
+          x(_exception as Object, StackTrace.current);
+        }
+        //x(_exception as AsyncException);
       });
     //}
 

lib/src/Core/IEventHandler.dart

@@ -1,46 +1,36 @@
-class IEventHandler
-{
-    Map<String, List<Function>> _events;
+class IEventHandler {
+  Map<String, List<Function>> _events = {};
 
-    register(String event)
-    {
+  register(String event) {
     _events[event.toLowerCase()] = [];
   }
 
-    IEventHandler()
-    {
-        _events = {};
-    }
+  IEventHandler() {}
 
-    emitArgs(String event, List arguments)
-    {
-        event = event.toLowerCase();
-        if (_events.containsKey(event))
-            for(var i = 0; i < _events[event].length; i++)
-                if (Function.apply(_events[event][i], arguments) != null)
-                    return true;
+  emitArgs(String event, List arguments) {
+    //event = event.toLowerCase();
+
+    var et = _events[event.toLowerCase()];
+    if (et != null) {
+      for (var i = 0; i < et.length; i++)
+        if (Function.apply(et[i], arguments) != null) return true;
+    }
 
     return false;
   }
 
-    on(String event, Function callback)
-    {
+  on(String event, Function callback) {
     event = event.toLowerCase();
-        // add
-        if (!_events.containsKey(event))
-            register(event);
-
-        _events[event].add(callback);
+    if (_events.containsKey(event)) register(event);
+    _events[event]?.add(callback);
     return this;
   }
 
-    off(event, callback)
-    {
+  off(event, callback) {
     event = event.toString();
-        if (_events.containsKey(event))
-        {
+    if (_events.containsKey(event)) {
       if (callback != null)
-              _events[event].remove(callback);
+        _events[event]?.remove(callback);
       else
         this._events[event] = [];
     }

lib/src/Data/AutoList.dart

@@ -2,14 +2,14 @@ import '../Core/IDestructible.dart';
 import 'Codec.dart';
 import 'dart:collection';
 
-class AutoList<T, ST> extends IDestructible with IterableMixin {
+class AutoList<T, ST> extends IDestructible with IterableMixin<T> {
   List<T> _list = <T>[];
 
-  ST _state;
-  bool _removableList;
+  ST? _state;
+  late bool _removableList;
 
-  sort(Function comparer) {
-    _list.sort(comparer);
+  sort(int Function(T, T)? compare) {
+    _list.sort(compare);
   }
 
   Iterator<T> get iterator => _list.iterator;
@@ -26,7 +26,7 @@ class AutoList<T, ST> extends IDestructible with IterableMixin {
 
   /// Create a new instance of AutoList
   /// <param name="state">State object to be included when an event is raised.</param>
-  AutoList([ST state, List<T> values]) {
+  AutoList([ST? state, List<T>? values]) {
     this._state = state;
     this._removableList = Codec.implementsInterface<T, IDestructible>();
 
@@ -105,8 +105,7 @@ class AutoList<T, ST> extends IDestructible with IterableMixin {
   /// </summary>
   clear() {
     if (_removableList)
-      _list
-          .forEach((x) => (x as IDestructible)?.off("destroy", _itemDestroyed));
+      _list.forEach((x) => (x as IDestructible).off("destroy", _itemDestroyed));
 
 //          lock (syncRoot)
     _list.clear();

lib/src/Data/BinaryList.dart

@@ -30,81 +30,55 @@ import 'DC.dart';
 import 'DataType.dart';
 import 'Guid.dart';
 
-class BinaryList
-{
+class BinaryList {
   var _list = <int>[];
 
   int get length => _list.length;
 
-    BinaryList addDateTime(DateTime value)
-    {
+  void addDateTime(DateTime value) {
     _list.addAll(DC.dateTimeToBytes(value));
-        return this;
   }
 
-    BinaryList insertDateTime(int position, DateTime value)
-    {
+  void insertDateTime(int position, DateTime value) {
     _list.insertAll(position, DC.dateTimeToBytes(value));
-        return this;
   }
 
-
-    BinaryList addDateTimeArray(List<DateTime> value)
-    {
+  void addDateTimeArray(List<DateTime> value) {
     _list.addAll(DC.dateTimeArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertDateTimeArray(int position, List<DateTime> value)
-    {
+  void insertDateTimeArray(int position, List<DateTime> value) {
     _list.insertAll(position, DC.dateTimeArrayToBytes(value));
-        return this;
   }
 
-    BinaryList addGuid(Guid value)
-    {
+  void addGuid(Guid value) {
     _list.addAll(DC.guidToBytes(value));
-        return this;
   }
 
-    BinaryList insertGuid(int position, Guid value)
-    {
+  void insertGuid(int position, Guid value) {
     _list.insertAll(position, DC.guidToBytes(value));
-        return this;
   }
 
-    BinaryList addGuidArray(List<Guid> value)
-    {
+  void addGuidArray(List<Guid> value) {
     _list.addAll(DC.guidArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertGuidArray(int position, List<Guid> value)
-    {
+  void insertGuidArray(int position, List<Guid> value) {
     _list.insertAll(position, DC.guidArrayToBytes(value));
-        return this;
   }
 
-
-    BinaryList addUint8Array(Uint8List value)
-    {
+  void addUint8Array(Uint8List value) {
     _list.addAll(value);
-        return this;
   }
 
-    BinaryList addDC(DC value)
-    {
+  void addDC(DC value) {
     _list.addAll(value.toArray());
-       return this;
   }
 
-    BinaryList insertUint8Array(int position, Uint8List value)
-    {
+  void insertUint8Array(int position, Uint8List value) {
     _list.insertAll(position, value);
-        return this;
   }
 
-
   /*
     BinaryList addHex(String value)
     {
@@ -117,434 +91,316 @@ class BinaryList
     }
   */
 
-    
-    BinaryList addString(String value)
-    {
+  void addString(String value) {
     _list.addAll(DC.stringToBytes(value));
-        return this;
   }
 
-    BinaryList insertString(int position, String value)
-    {
+  void insertString(int position, String value) {
     _list.insertAll(position, DC.stringToBytes(value));
-        return this;
   }
 
-    BinaryList addStringArray(List<String> value)
-    {
+  void addStringArray(List<String> value) {
     _list.addAll(DC.stringArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertStringArray(int position, List<String> value)
-    {
+  void insertStringArray(int position, List<String> value) {
     _list.insertAll(position, DC.stringArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertUint8(int position, int value)
-    {
+  void insertUint8(int position, int value) {
     _list.insert(position, value);
-        return this;
   }
 
-    BinaryList addUint8(int value)
-    {
+  void addUint8(int value) {
     _list.add(value);
-        return this;
   }
 
-    BinaryList addInt8(int value)
-    {
+  void addInt8(int value) {
     _list.add(value);
-        return this;
   }
 
-    BinaryList insertInt8(int position, int value)
-    {
+  void insertInt8(int position, int value) {
     _list.insert(position, value);
-        return this;
   }
 
-    BinaryList addInt8Array(Int8List value)
-    {
+  void addInt8Array(Int8List value) {
     _list.addAll(DC.int8ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertInt8Array(int position, Int8List value)
-    {
+  void insertInt8Array(int position, Int8List value) {
     _list.insertAll(position, DC.int8ArrayToBytes(value));
-        return this;
   }
 
-
-    BinaryList addChar(int value)
-    {
+  void addChar(int value) {
     _list.addAll(DC.charToBytes(value));
-        return this;
   }
 
-    BinaryList InsertChar(int position, int value)
-    {
+  void InsertChar(int position, int value) {
     _list.insertAll(position, DC.charToBytes(value));
-        return this;
   }
 
-    BinaryList addCharArray(Uint16List value)
-    {
+  void addCharArray(Uint16List value) {
     _list.addAll(DC.charArrayToBytes(value));
-        return this;
   }
 
-    BinaryList InsertCharArray(int position, Uint16List value)
-    {
+  void InsertCharArray(int position, Uint16List value) {
     _list.insertAll(position, DC.charArrayToBytes(value));
-        return this;
   }
 
-
-    BinaryList addBoolean(bool value)
-    {
+  void addBoolean(bool value) {
     _list.addAll(DC.boolToBytes(value));
-        return this;
   }
 
-    BinaryList insertBoolean(int position, bool value)
-    {
+  void insertBoolean(int position, bool value) {
     _list.insertAll(position, DC.boolToBytes(value));
-        return this;
   }
 
-    BinaryList addBooleanArray(List<bool> value)
-    {
+  void addBooleanArray(List<bool> value) {
     _list.addAll(DC.boolToBytes(value));
-        return this;
   }
 
-    BinaryList insertBooleanArray(int position, List<bool> value)
-    {
+  void insertBooleanArray(int position, List<bool> value) {
     _list.insertAll(position, DC.boolToBytes(value));
-        return this;
   }
 
-    BinaryList addUint16(int value)
-    {
+  void addUint16(int value) {
     _list.addAll(DC.uint16ToBytes(value));
-        return this;
   }
 
-    BinaryList insertUint16(int position, int value)
-    {
+  void insertUint16(int position, int value) {
     _list.insertAll(position, DC.uint16ToBytes(value));
-        return this;
   }
 
-    BinaryList addUint16Array(Uint16List value)
-    {
+  void addUint16Array(Uint16List value) {
     _list.addAll(DC.uint16ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertUint16Array(int position, Uint16List value)
-    {
+  void insertUint16Array(int position, Uint16List value) {
     _list.insertAll(position, DC.uint16ArrayToBytes(value));
-        return this;
   }
 
-
-    BinaryList addInt16(int value)
-    {
+  void addInt16(int value) {
     _list.addAll(DC.int16ToBytes(value));
-        return this;
   }
 
-    BinaryList insertInt16(int position, int value)
-    {
+  void insertInt16(int position, int value) {
     _list.insertAll(position, DC.int16ToBytes(value));
-        return this;
   }
 
-  
-    BinaryList addInt16Array(Int16List value)
-    {
+  void addInt16Array(Int16List value) {
     _list.addAll(DC.int16ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertInt16Array(int position, Int16List value)
-    {
+  void insertInt16Array(int position, Int16List value) {
     _list.insertAll(position, DC.int16ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList addUint32(int value)
-    {
+  void addUint32(int value) {
     _list.addAll(DC.uint32ToBytes(value));
-        return this;
   }
 
-    BinaryList insertUint32(int position, int value)
-    {
+  void insertUint32(int position, int value) {
     _list.insertAll(position, DC.uint32ToBytes(value));
-        return this;
   }
 
-    BinaryList addUint32Array(Uint32List value)
-    {
+  void addUint32Array(Uint32List value) {
     _list.addAll(DC.uint32ArrayToBytes(value));
-        return this;
   }
-    BinaryList InsertUint32Array(int position, Uint32List value)
-    {
+
+  void InsertUint32Array(int position, Uint32List value) {
     _list.insertAll(position, DC.uint32ArrayToBytes(value));
-        return this;
   }
 
-
-    BinaryList addInt32(int value)
-    {
+  void addInt32(int value) {
     _list.addAll(DC.int32ToBytes(value));
-        return this;
   }
 
-    BinaryList insertInt32(int position, int value)
-    {
+  void insertInt32(int position, int value) {
     _list.insertAll(position, DC.int32ToBytes(value));
-        return this;
   }
 
-    BinaryList addInt32Array(Int32List value)
-    {
+  void addInt32Array(Int32List value) {
     _list.addAll(DC.int32ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertInt32Array(int position, Int32List value)
-    {
+  void insertInt32Array(int position, Int32List value) {
     _list.insertAll(position, DC.int32ArrayToBytes(value));
-        return this;
   }
 
-
-    BinaryList addUint64(int value)
-    {
+  void addUint64(int value) {
     _list.addAll(DC.uint64ToBytes(value));
-        return this;
   }
 
-    BinaryList insertUint64(int position, int value)
-    {
+  void insertUint64(int position, int value) {
     _list.insertAll(position, DC.uint64ToBytes(value));
-        return this;
   }
 
-    BinaryList addUint64Array(Uint64List value)
-    {
+  void addUint64Array(Uint64List value) {
     _list.addAll(DC.uint64ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList InsertUint64Array(int position, Uint64List value)
-    {
+  void InsertUint64Array(int position, Uint64List value) {
     _list.insertAll(position, DC.uint64ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList addInt64(int value)
-    {
+  void addInt64(int value) {
     _list.addAll(DC.int64ToBytes(value));
-        return this;
   }
 
-    BinaryList insertInt64(int position, int value)
-    {
+  void insertInt64(int position, int value) {
     _list.insertAll(position, DC.int64ToBytes(value));
-        return this;
   }
 
-    BinaryList addInt64Array(Int64List value)
-    {
+  void addInt64Array(Int64List value) {
     _list.addAll(DC.int64ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertInt64Array(int position, Int64List value)
-    {
+  void insertInt64Array(int position, Int64List value) {
     _list.insertAll(position, DC.int64ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList addFloat32(double value)
-    {
+  void addFloat32(double value) {
     _list.addAll(DC.float32ToBytes(value));
-        return this;
   }
 
-    BinaryList insertFloat32(int position, double value)
-    {
+  void insertFloat32(int position, double value) {
     _list.insertAll(position, DC.float32ToBytes(value));
-        return this;
   }
 
-    BinaryList addFloat32Array(Float32List value)
-    {
+  void addFloat32Array(Float32List value) {
     _list.addAll(DC.float32ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertFloat32Array(int position, Float32List value)
-    {
+  void insertFloat32Array(int position, Float32List value) {
     _list.insertAll(position, DC.float32ArrayToBytes(value));
-        return this;
   }
 
-
-    BinaryList addFloat64(double value)
-    {
+  void addFloat64(double value) {
     _list.addAll(DC.float64ToBytes(value));
-        return this;
   }
 
-    BinaryList insertFloat64(int position, double value)
-    {
+  void insertFloat64(int position, double value) {
     _list.insertAll(position, DC.float64ToBytes(value));
-        return this;
   }
 
-    BinaryList addFloat64Array(Float64List value)
-    {
+  void addFloat64Array(Float64List value) {
     _list.addAll(DC.float64ArrayToBytes(value));
-        return this;
   }
 
-    BinaryList insertFloat64Array(int position, Float64List value)
-    {
+  void insertFloat64Array(int position, Float64List value) {
     _list.insertAll(position, DC.float64ArrayToBytes(value));
-        return this;
   }
 
-
-
-    BinaryList add(type, value)
-    {
-        switch (type)
-        {
+  void add(type, value) {
+    switch (type) {
       case DataType.Bool:
         addBoolean(value);
-                return this;
+        return;
       case DataType.BoolArray:
         addBooleanArray(value);
-                return this;
+        return;
       case DataType.UInt8:
         addUint8(value);
-                return this;
+        return;
       case DataType.UInt8Array:
         addUint8Array(value);
-                return this;
+        return;
       case DataType.Int8:
         addInt8(value);
-                return this;
+        return;
       case DataType.Int8Array:
         addInt8Array(value);
-                return this;
+        return;
       case DataType.Char:
         addChar(value);
-                return this;
+        return;
       case DataType.CharArray:
         addCharArray(value);
-                return this;
+        return;
       case DataType.UInt16:
         addUint16(value);
-                return this;
+        return;
       case DataType.UInt16Array:
         addUint16Array(value);
-                return this;
+        return;
       case DataType.Int16:
         addInt16(value);
-                return this;
+        return;
       case DataType.Int16Array:
         addInt16Array(value);
-                return this;
+        return;
       case DataType.UInt32:
         addUint32(value);
-                return this;
+        return;
       case DataType.UInt32Array:
         addUint32Array(value);
-                return this;
+        return;
       case DataType.Int32:
         addInt32(value);
-                return this;
+        return;
       case DataType.Int32Array:
         addInt32Array(value);
-                return this;
+        return;
       case DataType.UInt64:
         addUint64(value);
-                return this;
+        return;
       case DataType.UInt64Array:
         addUint64Array(value);
-                return this;
+        return;
       case DataType.Int64:
         addInt64(value);
-                return this;
+        return;
       case DataType.Int64Array:
         addInt64Array(value);
-                return this;
+        return;
 
       case DataType.Float32:
         addFloat32(value);
-                return this;
+        return;
       case DataType.Float32Array:
         addFloat32Array(value);
-                return this;
+        return;
 
       case DataType.Float64:
         addFloat64(value);
-                return this;
+        return;
       case DataType.Float64Array:
         addFloat64Array(value);
-                return this;
+        return;
 
       case DataType.String:
         addString(value);
-                return this;
+        return;
       case DataType.StringArray:
         addStringArray(value);
-                return this;
+        return;
 
       case DataType.DateTime:
         addDateTime(value);
-                return this;
+        return;
       case DataType.DateTimeArray:
         addDateTimeArray(value);
-                return this;
+        return;
 
       default:
         throw new Exception("Not Implemented " + type.ToString());
       //return this;
     }
   }
+
   /// <summary>
   /// Convert the _list to an array of bytes
   /// </summary>
   /// <returns>Bytes array</returns>
-    Uint8List toArray()
-    {
+  Uint8List toArray() {
     return Uint8List.fromList(_list);
   }
 
-
-    DC toDC()
-    {
+  DC toDC() {
     return new DC.fromUint8Array(toArray());
   }
 
-    
-    AsyncReply<dynamic> done()
-    {
-        return null;
-        //
+  AsyncReply<dynamic> done() {
+    return AsyncReply.ready(null);
   }
-    
-
 }

lib/src/Data/Codec.dart

@@ -21,6 +21,11 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 
 */
+
+import '../Core/AsyncException.dart';
+import '../Core/ErrorType.dart';
+import '../Core/ExceptionCode.dart';
+
 import '../Resource/Template/TemplateType.dart';
 
 import 'DataType.dart';
@@ -93,7 +98,7 @@ class Codec {
   /// <param name="next">Next structure to compare with the initial</param>
   /// <param name="connection">DistributedConnection is required in case a structure holds items at the other end</param>
   static int compareStructures(
-      Structure initial, Structure next, DistributedConnection connection) {
+      Structure? initial, Structure? next, DistributedConnection connection) {
     if (next == null) return StructureComparisonResult.Null;
 
     if (initial == null) return StructureComparisonResult.Structure;
@@ -126,7 +131,7 @@ class Codec {
   /// <param name="initial">Initial record to compare with</param>
   /// <param name="next">Next record to compare with the initial</param>
   /// <param name="connection">DistributedConnection is required in case a structure holds items at the other end</param>
-  static int compareRecords(IRecord initial, IRecord next) {
+  static int compareRecords(IRecord? initial, IRecord? next) {
     if (next == null) return RecordComparisonResult.Null;
 
     if (initial == null) return RecordComparisonResult.Record;
@@ -139,9 +144,9 @@ class Codec {
     return RecordComparisonResult.Record;
   }
 
-  static AsyncBag parseRecordArray(
+  static AsyncBag<IRecord?> parseRecordArray(
       DC data, int offset, int length, DistributedConnection connection) {
-    var reply = new AsyncBag();
+    var reply = new AsyncBag<IRecord?>();
 
     if (length == 0) {
       reply.seal();
@@ -161,12 +166,12 @@ class Codec {
       var template =
           Warehouse.getTemplateByClassId(classId, TemplateType.Record);
 
-      reply.arrayType = template.definedType;
+      reply.arrayType = template?.definedType;
 
-      AsyncReply<IRecord> previous = null;
+      AsyncReply<IRecord?>? previous = null;
 
       if (result == RecordComparisonResult.Null)
-        previous = new AsyncReply<IRecord>.ready(null);
+        previous = AsyncReply<IRecord?>.ready(null);
       else if (result == RecordComparisonResult.Record ||
           result == RecordComparisonResult.RecordSameType) {
         var cs = data.getUint32(offset);
@@ -176,13 +181,13 @@ class Codec {
         offset += recordLength;
       }
 
-      reply.add(previous);
+      reply.add(previous as AsyncReply<IRecord?>);
 
       while (offset < end) {
         result = data[offset++];
 
         if (result == RecordComparisonResult.Null)
-          previous = new AsyncReply<IRecord>.ready(null);
+          previous = new AsyncReply<IRecord?>.ready(null);
         else if (result == RecordComparisonResult.Record ||
             result == RecordComparisonResult.RecordSameType) {
           var cs = data.getUint32(offset);
@@ -193,14 +198,14 @@ class Codec {
           // do nothing
         }
 
-        reply.add(previous);
+        reply.add(previous as AsyncReply<IRecord?>);
       }
     } else {
-      AsyncReply<IRecord> previous = null;
-      Guid classId = null;
+      AsyncReply<IRecord?>? previous = null;
+      Guid? classId = null;
 
       if (result == RecordComparisonResult.Null)
-        previous = new AsyncReply<IRecord>.ready(null);
+        previous = new AsyncReply<IRecord?>.ready(null);
       else if (result == RecordComparisonResult.Record) {
         var cs = data.getUint32(offset);
         var recordLength = cs - 16;
@@ -211,13 +216,13 @@ class Codec {
         offset += recordLength;
       }
 
-      reply.add(previous);
+      reply.add(previous as AsyncReply<IRecord?>);
 
       while (offset < end) {
         result = data[offset++];
 
         if (result == RecordComparisonResult.Null)
-          previous = new AsyncReply<IRecord>.ready(null);
+          previous = new AsyncReply<IRecord?>.ready(null);
         else if (result == RecordComparisonResult.Record) {
           var cs = data.getUint32(offset);
           var recordLength = cs - 16;
@@ -236,7 +241,7 @@ class Codec {
           // do nothing
         }
 
-        reply.add(previous);
+        reply.add(previous as AsyncReply<IRecord?>);
       }
     }
 
@@ -301,7 +306,7 @@ class Codec {
 
   static AsyncReply<IRecord> parseRecord(
       DC data, int offset, int length, DistributedConnection connection,
-      [Guid classId = null]) {
+      [Guid? classId = null]) {
     var reply = new AsyncReply<IRecord>();
 
     if (classId == null) {
@@ -317,7 +322,7 @@ class Codec {
       parseVarArray(data, offset, length, connection).then((ar) {
         if (template.definedType != null) {
           var record =
-              Warehouse.createInstance(template.definedType) as IRecord;
+              Warehouse.createInstance(template.definedType as Type) as IRecord;
 
           Map<String, dynamic> value = {};
 
@@ -337,8 +342,11 @@ class Codec {
         }
       });
     } else {
-      connection.getTemplate(classId).then<dynamic>((tmp) {
-        parseVarArray(data, offset, length, connection).then<dynamic>((ar) {
+      connection.getTemplate(classId)
+        ..then((tmp) {
+          if (tmp != null) {
+            parseVarArray(data, offset, length, connection)
+              ..then((ar) {
                 var record = new Record();
 
                 for (var i = 0; i < tmp.properties.length; i++)
@@ -346,7 +354,12 @@ class Codec {
 
                 reply.trigger(record);
               });
-      }).error((x) => reply.triggerError(x));
+          } else {
+            reply.triggerError(AsyncException(ErrorType.Management,
+                ExceptionCode.TemplateNotFound.index, null));
+          }
+        })
+        ..error((x) => reply.triggerError(x));
     }
 
     return reply;
@@ -377,9 +390,9 @@ class Codec {
   }
 
   static DC composeRecordArray<T extends IRecord>(
-      List<T> records, DistributedConnection connection,
+      List<T>? records, DistributedConnection connection,
       [bool prependLength = false]) {
-    if (records == null || records?.length == 0)
+    if (records == null || records.length == 0)
       return prependLength ? new DC(4) : new DC(0);
 
     var rt = new BinaryList();
@@ -391,14 +404,14 @@ class Codec {
     if (isTyped) {
       var template = Warehouse.getTemplateByType(T);
 
-      if (template != null) {
+      //if (template != null) {
       // typed array ... no need to add class id , it will be included at the first entry
       rt.addUint8(0x10 | comparsion);
       rt.addGuid(template.classId);
-      } else // something wrong
-      {
-        throw new Exception("Template for type `${T}` not found.");
-      }
+      //} else // something wrong
+      //{
+      //  throw new Exception("Template for type `${T}` not found.");
+      //}
 
       if (comparsion == RecordComparisonResult.Record)
         rt.addDC(composeRecord(records[0], connection, false, true));
@@ -468,17 +481,17 @@ class Codec {
   /// <param name="prependLength">If true, prepend the length as UInt32 at the beginning of the returned bytes array</param>
   /// <returns>Array of bytes in the network byte order</returns>
   static DC composeStructureArray(
-      List<Structure> structures, DistributedConnection connection,
+      List<Structure>? structures, DistributedConnection connection,
       [bool prependLength = false]) {
-    if (structures == null || structures?.length == 0)
+    if (structures == null || structures.length == 0)
       return prependLength ? new DC(4) : new DC(0);
 
     var rt = new BinaryList();
     var comparsion = StructureComparisonResult.Structure;
 
     rt
-        .addUint8(comparsion)
-        .addDC(composeStructure(structures[0], connection, true, true, true));
+      ..addUint8(comparsion)
+      ..addDC(composeStructure(structures[0], connection, true, true, true));
 
     for (var i = 1; i < structures.length; i++) {
       comparsion =
@@ -508,9 +521,9 @@ class Codec {
   /// <param name="length">Number of bytes to parse</param>
   /// <param name="connection">DistributedConnection is required in case a structure in the array holds items at the other end</param>
   /// <returns>Array of structures</returns>
-  static AsyncBag<Structure> parseStructureArray(
+  static AsyncBag<Structure?> parseStructureArray(
       DC data, int offset, int length, DistributedConnection connection) {
-    var reply = new AsyncBag<Structure>();
+    var reply = new AsyncBag<Structure?>();
     if (length == 0) {
       reply.seal();
       return reply;
@@ -520,14 +533,14 @@ class Codec {
 
     var result = data[offset++];
 
-    AsyncReply<Structure> previous = null;
+    AsyncReply<Structure?>? previous = null;
     // string[] previousKeys = null;
     // DataType[] previousTypes = null;
 
     StructureMetadata metadata = new StructureMetadata();
 
     if (result == StructureComparisonResult.Null)
-      previous = new AsyncReply<Structure>.ready(null);
+      previous = new AsyncReply<Structure?>.ready(null);
     else if (result == StructureComparisonResult.Structure) {
       int cs = data.getUint32(offset);
       offset += 4;
@@ -535,13 +548,13 @@ class Codec {
       offset += cs;
     }
 
-    reply.add(previous);
+    reply.add(previous as AsyncReply<Structure?>);
 
     while (offset < end) {
       result = data[offset++];
 
       if (result == StructureComparisonResult.Null)
-        previous = new AsyncReply<Structure>.ready(null);
+        previous = new AsyncReply<Structure?>.ready(null);
       else if (result == StructureComparisonResult.Structure) {
         int cs = data.getUint32(offset);
         offset += 4;
@@ -562,7 +575,7 @@ class Codec {
         offset += cs;
       }
 
-      reply.add(previous);
+      reply.add(previous as AsyncReply<Structure?>);
     }
 
     reply.seal();
@@ -587,7 +600,10 @@ class Codec {
     if (includeKeys) {
       for (var k in value.keys) {
         var key = DC.stringToBytes(k);
-        rt.addUint8(key.length).addDC(key).addDC(compose(value[k], connection));
+        rt
+          ..addUint8(key.length)
+          ..addDC(key)
+          ..addDC(compose(value[k], connection));
       }
     } else {
       for (var k in value.keys)
@@ -613,9 +629,9 @@ class Codec {
   /// <returns>Structure</returns>
   static AsyncReply<Structure> parseStructure(
       DC data, int offset, int length, DistributedConnection connection,
-      [StructureMetadata metadata = null,
-      List<String> keys = null,
-      List<int> types =
+      [StructureMetadata? metadata = null,
+      List<String>? keys = null,
+      List<int>? types =
           null]) // out string[] parsedKeys, out DataType[] parsedTypes, string[] keys = null, DataType[] types = null)
   {
     var reply = new AsyncReply<Structure>();
@@ -685,9 +701,8 @@ class Codec {
   /// <param name="connection">DistributedConnection is required in case a structure in the array holds items at the other end.</param>
   /// <param name="dataType">DataType, in case the data is not prepended with DataType</param>
   /// <returns>Value</returns>
-  static AsyncReply<dynamic> parse(
-      DC data, int offset, DistributedConnection connection,
-      [SizeObject sizeObject, int dataType = DataType.Unspecified]) {
+  static AsyncReply parse(DC data, int offset, DistributedConnection connection,
+      [SizeObject? sizeObject, int dataType = DataType.Unspecified]) {
     bool isArray;
     int t;
 
@@ -850,7 +865,8 @@ class Codec {
       }
     }
 
-    return null;
+    // @TODO: Throw exception
+    return AsyncReply.ready(null);
   }
 
   /// <summary>
@@ -859,8 +875,8 @@ class Codec {
   /// <param name="data">Bytes array</param>
   /// <param name="offset">Zero-indexed offset.</param>
   /// <returns>Resource</returns>
-  static AsyncReply<IResource> parseResource(DC data, int offset) {
-    return Warehouse.get(data.getUint32(offset));
+  static AsyncReply<IResource?> parseResource(DC data, int offset) {
+    return Warehouse.getById(data.getUint32(offset));
   }
 
   /// <summary>
@@ -904,7 +920,7 @@ class Codec {
   /// <returns>Null, same, local, distributed or same class distributed.</returns>
 
   static int compareResources(
-      IResource initial, IResource next, DistributedConnection connection) {
+      IResource? initial, IResource? next, DistributedConnection connection) {
     if (next == null)
       return ResourceComparisonResult.Null;
     else if (next == initial)
@@ -924,13 +940,12 @@ class Codec {
   static DC composeResource(
       IResource resource, DistributedConnection connection) {
     if (isLocalResource(resource, connection))
-      return DC.uint32ToBytes((resource as DistributedResource).id);
+      return DC.uint32ToBytes((resource as DistributedResource).id as int);
     else {
-      return new BinaryList()
-          .addGuid(resource.instance.template.classId)
-          .addUint32(resource.instance.id)
+      return (BinaryList()
+            ..addGuid(resource.instance?.template.classId as Guid)
+            ..addUint32(resource.instance?.id as int))
           .toDC();
-      //return BinaryList.ToBytes(resource.Instance.Template.ClassId, resource.Instance.Id);
     }
   }
 
@@ -943,9 +958,9 @@ class Codec {
   /// <returns>Array of bytes in the network byte order.</returns>
 
   static DC composeResourceArray<T extends IResource>(
-      List<T> resources, DistributedConnection connection,
+      List<T>? resources, DistributedConnection connection,
       [bool prependLength = false]) {
-    if (resources == null || resources?.length == 0)
+    if (resources == null || resources.length == 0)
       return prependLength ? new DC(4) : new DC(0);
 
     var rt = new BinaryList();
@@ -971,17 +986,17 @@ class Codec {
     }
 
     if (comparsion == ResourceComparisonResult.Local)
-      rt.addUint32((resources[0] as DistributedResource).id);
+      rt.addUint32((resources[0] as DistributedResource).id as int);
     else if (comparsion == ResourceComparisonResult.Distributed)
-      rt.addUint32(resources[0].instance.id);
+      rt.addUint32(resources[0].instance?.id as int);
 
     for (var i = 1; i < resources.length; i++) {
       comparsion = compareResources(resources[i - 1], resources[i], connection);
       rt.addUint8(comparsion);
       if (comparsion == ResourceComparisonResult.Local)
-        rt.addUint32((resources[i] as DistributedResource).id);
+        rt.addUint32((resources[i] as DistributedResource).id as int);
       else if (comparsion == ResourceComparisonResult.Distributed)
-        rt.addUint32(resources[i].instance.id);
+        rt.addUint32(resources[i].instance?.id as int);
     }
 
     if (prependLength) rt.insertInt32(0, rt.length);
@@ -997,11 +1012,11 @@ class Codec {
   /// <param name="offset">Zero-indexed offset.</param>
   /// <param name="connection">DistributedConnection is required to fetch resources.</param>
   /// <returns>Array of resources.</returns>
-  static AsyncBag<IResource> parseResourceArray(
+  static AsyncBag<IResource?> parseResourceArray(
       DC data, int offset, int length, DistributedConnection connection) {
     //print("parseResourceArray ${offset} ${length}");
 
-    var reply = new AsyncBag<IResource>();
+    var reply = new AsyncBag<IResource?>();
     if (length == 0) {
       reply.seal();
       return reply;
@@ -1031,27 +1046,27 @@ class Codec {
       reply.arrayType = tmp?.definedType;
     }
 
-    AsyncReply<IResource> previous = null;
+    AsyncReply<IResource?>? previous = null;
 
     if (result == ResourceComparisonResult.Null)
-      previous = new AsyncReply<IResource>.ready(null);
+      previous = new AsyncReply<IResource?>.ready(null);
     else if (result == ResourceComparisonResult.Local) {
-      previous = Warehouse.get(data.getUint32(offset));
+      previous = Warehouse.getById(data.getUint32(offset));
       offset += 4;
     } else if (result == ResourceComparisonResult.Distributed) {
       previous = connection.fetch(data.getUint32(offset));
       offset += 4;
     }
 
-    reply.add(previous);
+    reply.add(previous as AsyncReply<IResource?>);
 
     while (offset < end) {
       result = data[offset++];
 
-      AsyncReply<IResource> current = null;
+      AsyncReply<IResource?>? current = null;
 
       if (result == ResourceComparisonResult.Null) {
-        current = new AsyncReply<IResource>.ready(null);
+        current = new AsyncReply<IResource?>.ready(null);
       } else if (result == ResourceComparisonResult.Same) {
         current = previous;
       } else if (result == ResourceComparisonResult.Local) {
@@ -1062,7 +1077,7 @@ class Codec {
         offset += 4;
       }
 
-      reply.add(current);
+      reply.add(current as AsyncReply<IResource?>);
 
       previous = current;
     }
@@ -1146,10 +1161,10 @@ class Codec {
   static DC composePropertyValue(PropertyValue propertyValue,
       DistributedConnection connection) //, bool includeAge = true)
   {
-    return new BinaryList()
-        .addUint64(propertyValue.age)
-        .addDateTime(propertyValue.date)
-        .addDC(compose(propertyValue.value, connection))
+    return (BinaryList()
+          ..addUint64(propertyValue.age)
+          ..addDateTime(propertyValue.date)
+          ..addDC(compose(propertyValue.value, connection)))
         .toDC();
   }
 
@@ -1194,7 +1209,8 @@ class Codec {
   static AsyncReply<KeyList<PropertyTemplate, List<PropertyValue>>>
       parseHistory(DC data, int offset, int length, IResource resource,
           DistributedConnection connection) {
-    var list = new KeyList<PropertyTemplate, List<PropertyValue>>();
+    var list = <
+        PropertyTemplate>[]; //new KeyList<PropertyTemplate, List<PropertyValue>?>();
 
     var reply =
         new AsyncReply<KeyList<PropertyTemplate, List<PropertyValue>>>();
@@ -1207,20 +1223,26 @@ class Codec {
 
     while (offset < ends) {
       var index = data[offset++];
-      var pt = resource.instance.template.getPropertyTemplateByIndex(index);
-      list.add(pt, null);
+      var pt = resource.instance?.template.getPropertyTemplateByIndex(index);
+      if (pt != null) {
+        list.add(pt); //, null);
         var cs = data.getUint32(offset);
         offset += 4;
         bagOfBags.add(parsePropertyValueArray(data, offset, cs, connection));
         offset += cs;
       }
+    }
 
     bagOfBags.seal();
 
     bagOfBags.then((x) {
-      for (var i = 0; i < list.length; i++) list[list.keys.elementAt(i)] = x[i];
+      var keyList = KeyList<PropertyTemplate, List<PropertyValue>>();
 
-      reply.trigger(list);
+      for (var i = 0; i < list.length; i++) keyList.add(list[i], x[i]);
+
+      //list[list.keys.elementAt(i)] = x[i];
+
+      reply.trigger(keyList);
     });
 
     return reply;
@@ -1239,8 +1261,9 @@ class Codec {
     var rt = new BinaryList();
 
     for (var i = 0; i < history.length; i++)
-      rt.addUint8(history.keys.elementAt(i).index).addDC(
-          composePropertyValueArray(
+      rt
+        ..addUint8(history.keys.elementAt(i).index)
+        ..addDC(composePropertyValueArray(
             history.values.elementAt(i), connection, true));
 
     if (prependLength) rt.insertInt32(0, rt.length);
@@ -1292,7 +1315,7 @@ class Codec {
     if (value is Function(DistributedConnection))
       value = Function.apply(value, [connection]);
     else if (value is DistributedPropertyContext)
-      value = (value as DistributedPropertyContext).method(connection);
+      value = value.method?.call(connection);
 
     var type = getDataType(value, connection);
     var rt = new BinaryList();
@@ -1304,15 +1327,17 @@ class Codec {
 
       case DataType.String:
         var st = DC.stringToBytes(value);
-        rt.addInt32(st.length).addDC(st);
+        rt
+          ..addInt32(st.length)
+          ..addDC(st);
         break;
 
       case DataType.Resource:
-        rt.addUint32((value as DistributedResource).id);
+        rt.addUint32((value as DistributedResource).id as int);
         break;
 
       case DataType.DistributedResource:
-        rt.addUint32((value as IResource).instance.id);
+        rt.addUint32((value as IResource).instance?.id as int);
         break;
 
       case DataType.Structure:

lib/src/Data/DC.dart

@@ -34,8 +34,8 @@ const UNIX_EPOCH = 621355968000000000;
 const TWO_PWR_32 = (1 << 16) * (1 << 16);
 
 class DC with IterableMixin<int> {
-  Uint8List _data;
-  ByteData _dv;
+  late Uint8List _data;
+  late ByteData _dv;
 
   DC(int length) {
     _data = new Uint8List(length);
@@ -245,7 +245,8 @@ class DC with IterableMixin<int> {
     var list = new BinaryList();
     for (var i = 0; i < value.length; i++) {
       var s = DC.stringToBytes(value[i]);
-      list.addUint32(s.length).addUint8Array(s.toArray());
+      list..addUint32(s.length)
+          ..addUint8Array(s.toArray());
     }
 
     return list.toDC();
@@ -289,67 +290,67 @@ class DC with IterableMixin<int> {
         Uint8List.fromList(_data.getRange(offset, offset + length).toList()));
   }
 
-  getInt8(int offset) {
+  int getInt8(int offset) {
     return _dv.getInt8(offset);
   }
 
-  getUint8(int offset) {
+  int getUint8(int offset) {
     return _data[offset]; // this.dv.getUint8(offset);
   }
 
-  getInt16(int offset) {
+  int getInt16(int offset) {
     return _dv.getInt16(offset);
   }
 
-  getUint16(int offset) {
+  int getUint16(int offset) {
     return _dv.getUint16(offset);
   }
 
-  getInt32(int offset) {
+  int getInt32(int offset) {
     return _dv.getInt32(offset);
   }
 
-  getUint32(int offset) {
+  int getUint32(int offset) {
     return _dv.getUint32(offset);
   }
 
-  getFloat32(int offset) {
+  double getFloat32(int offset) {
     return _dv.getFloat32(offset);
   }
 
-  getFloat64(int offset) {
+  double getFloat64(int offset) {
     return _dv.getFloat64(offset);
   }
 
-  setInt8(int offset, int value) {
+  void setInt8(int offset, int value) {
     return _dv.setInt8(offset, value);
   }
 
-  setUint8(int offset, int value) {
+  void setUint8(int offset, int value) {
     return _dv.setUint8(offset, value);
   }
 
-  setInt16(int offset, int value) {
+  void setInt16(int offset, int value) {
     return _dv.setInt16(offset, value);
   }
 
-  setUint16(int offset, int value) {
+  void setUint16(int offset, int value) {
     return _dv.setUint16(offset, value);
   }
 
-  setInt32(int offset, int value) {
+  void setInt32(int offset, int value) {
     return _dv.setInt32(offset, value);
   }
 
-  setUint32(int offset, int value) {
+  void setUint32(int offset, int value) {
     return _dv.setUint32(offset, value);
   }
 
-  setFloat32(int offset, double value) {
+  void setFloat32(int offset, double value) {
     return _dv.setFloat32(offset, value);
   }
 
-  setFloat64(int offset, double value) {
+  void setFloat64(int offset, double value) {
     return _dv.setFloat64(offset, value);
   }
 
@@ -397,7 +398,7 @@ class DC with IterableMixin<int> {
     return this.getUint8(offset) > 0;
   }
 
-  setBoolean(int offset, bool value) {
+  void setBoolean(int offset, bool value) {
     this.setUint8(offset, value ? 1 : 0);
   }
 
@@ -411,7 +412,7 @@ class DC with IterableMixin<int> {
     return String.fromCharCode(this.getUint16(offset));
   }
 
-  setChar(int offset, int value) {
+  void setChar(int offset, int value) {
     this.setUint16(offset, value); //value.codeUnitAt(0));
   }
 
@@ -462,11 +463,11 @@ class DC with IterableMixin<int> {
     return rt;
   }
 
-  getInt64(offset) {
+  int getInt64(offset) {
     return _dv.getUint64(offset);
   }
 
-  getUint64(offset) {
+  int getUint64(offset) {
     return _dv.getInt64(offset);
   }
 
@@ -478,7 +479,7 @@ class DC with IterableMixin<int> {
     _dv.setUint64(offset, value);
   }
 
-  setDateTime(offset, DateTime value) {
+  void setDateTime(offset, DateTime value) {
     // Unix Epoch
     var ticks = UNIX_EPOCH + (value.millisecondsSinceEpoch * 10000);
     this.setUint64(offset, ticks);
@@ -500,7 +501,7 @@ class DC with IterableMixin<int> {
     return new Guid(this.clip(offset, 16));
   }
 
-  setGuid(int offset, Guid guid) {
+  void setGuid(int offset, Guid guid) {
     set(guid.value, offset);
   }
 

lib/src/Data/Guid.dart

@@ -3,8 +3,8 @@ import 'DC.dart';
 class Guid {
   DC _data;
 
-  Guid(DC data) {
-    _data = data;
+  Guid(this._data) {
+    
   }
 
   DC get value => _data;

lib/src/Data/KeyList.dart

@@ -43,9 +43,9 @@ class KeyList<KT, T> extends IEventHandler with MapMixin<KT, T> {
 
   at(int index) => _map.values.elementAt(index);
 
-  bool _removableList;
+  late bool _removableList;
 
-  T take(KT key) {
+  T? take(KT key) {
     if (_map.containsKey(key)) {
       var v = _map[key];
       remove(key);
@@ -89,20 +89,20 @@ class KeyList<KT, T> extends IEventHandler with MapMixin<KT, T> {
   clear() {
     if (_removableList)
       for (var v in _map.values)
-        (v as IDestructible)?.off("destroy", _itemDestroyed);
+        (v as IDestructible).off("destroy", _itemDestroyed);
 
     _map.clear();
 
     emitArgs("cleared", [this]);
   }
 
-  T remove(key) {
+  T? remove(key) {
     if (!_map.containsKey(key)) return null;
 
     var value = _map[key];
 
     if (_removableList)
-      (value as IDestructible)?.off("destroy", _itemDestroyed);
+      (value as IDestructible).off("destroy", _itemDestroyed);
 
     _map.remove(key);
 

lib/src/Data/Record.dart

@@ -4,7 +4,7 @@ import 'IRecord.dart';
 import 'KeyList.dart';
 
 class Record extends KeyList with IRecord {
-  Map<String, dynamic> _props;
+  Map<String, dynamic> _props = Map<String, dynamic>();
 
   @override
   Map<String, dynamic> serialize() {

lib/src/Data/SizeObject.dart

@@ -1,4 +1,3 @@
-class SizeObject
-{
-  int size;
+class SizeObject {
+  int size = 0;
 }

lib/src/Data/StructureMetadata.dart

@@ -1,8 +1,6 @@
-class StructureMetadata
-{
-
-  List<String> keys;
-  List<int> types;
+class StructureMetadata {
+  List<String>? keys; // = <String>[];
+  List<int>? types;//
 
   //const StructureMetadata(this.keys, this.types);
 }

lib/src/Net/IIP/DistributedPropertyContext.dart

@@ -1,18 +1,11 @@
 import 'DistributedConnection.dart';
-class DistributedPropertyContext
-{
+
+class DistributedPropertyContext {
   dynamic value;
-    DistributedConnection connection;
-    dynamic Function(DistributedConnection) method;
+  DistributedConnection? connection;
+  dynamic Function(DistributedConnection)? method;
 
+  DistributedPropertyContext(this.method) {}
 
-    DistributedPropertyContext(this.method)
-    {
-
-    }
-
-    DistributedPropertyContext.setter(this.value, this.connection)
-    {
-
-    }
+  DistributedPropertyContext.setter(this.value, this.connection) {}
 }

lib/src/Net/IIP/DistributedResource.dart

@@ -22,6 +22,9 @@ SOFTWARE.
 
 */
 
+
+import '../../Resource/Instance.dart';
+
 import '../../Core/AsyncException.dart';
 import '../../Core/ErrorType.dart';
 import '../../Core/ExceptionCode.dart';
@@ -40,18 +43,17 @@ import '../Packets/IIPPacketAction.dart';
 
 import '../../Resource/Template/EventTemplate.dart';
 
-
 class DistributedResource extends IResource {
-  int _instanceId;
-  DistributedConnection _connection;
+  int? _instanceId;
+  DistributedConnection? _connection;
 
   bool _attached = false;
   //bool _isReady = false;
 
-  String _link;
-  int _age;
+  String? _link;
+  int? _age;
 
-  List _properties;
+  List _properties = [];
   bool _destroyed = false;
 
   List<KeyValuePair<int, dynamic>> _queued_updates = [];
@@ -59,17 +61,17 @@ class DistributedResource extends IResource {
   /// <summary>
   /// Connection responsible for the distributed resource.
   /// </summary>
-  DistributedConnection get connection => _connection;
+  DistributedConnection? get connection => _connection;
 
   /// <summary>
   /// Resource link
   /// </summary>
-  String get link => _link;
+  String? get link => _link;
 
   /// <summary>
   /// Instance Id given by the other end.
   /// </summary>
-  int get id => _instanceId;
+  int? get id => _instanceId;
 
   //bool get destroyed => _destroyed;
 
@@ -84,7 +86,7 @@ class DistributedResource extends IResource {
   void destroy() {
     _destroyed = true;
     _attached = false;
-    _connection.sendDetachRequest(_instanceId);
+    _connection?.sendDetachRequest(_instanceId as int);
     emitArgs("destroy", [this]);
   }
 
@@ -137,13 +139,19 @@ class DistributedResource extends IResource {
   /// </summary>
   /// <returns></returns>
   List<PropertyValue> internal_serialize() {
-    var props = new List<PropertyValue>(_properties.length);
+    // var props = _properties as List;
+    // var rt = List<PropertyValue>(_properties.length);
 
-    for (var i = 0; i < _properties.length; i++)
-      props[i] = new PropertyValue(
-          _properties[i], instance.getAge(i), instance.getModificationDate(i));
+    // for (var i = 0; i < _properties.length; i++)
+    //   rt[i] = new PropertyValue(_properties[i], instance?.getAge(i) as int,
+    //       instance?.getModificationDate(i) as DateTime);
 
-    return props;
+    return List<PropertyValue>.generate(
+        _properties.length,
+        (i) => PropertyValue(_properties[i], instance?.getAge(i) as int,
+            instance?.getModificationDate(i) as DateTime));
+
+    //return rt;
   }
 
   bool internal_attach(List<PropertyValue> properties) {
@@ -152,14 +160,16 @@ class DistributedResource extends IResource {
     else {
       _suspended = false;
 
-      _properties = new List(properties.length); // object[properties.Length];
+      //_properties = new List(properties.length); // object[properties.Length];
 
       //_events = new DistributedResourceEvent[Instance.Template.Events.Length];
 
       for (var i = 0; i < properties.length; i++) {
-        instance.setAge(i, properties[i].age);
-        instance.setModificationDate(i, properties[i].date);
-        _properties[i] = properties[i].value;
+        instance?.setAge(i, properties[i].age);
+        instance?.setModificationDate(i, properties[i].date);
+
+        _properties.add(properties[i].value);
+        //_properties[i] = properties[i].value;
       }
 
       // trigger holded events/property updates.
@@ -180,9 +190,12 @@ class DistributedResource extends IResource {
   }
 
   AsyncReply<dynamic> listen(event) {
-    EventTemplate et = event is EventTemplate
+    if (_destroyed) throw new Exception("Trying to access destroyed object");
+    if (_suspended) throw new Exception("Trying to access suspended object");
+
+    EventTemplate? et = event is EventTemplate
         ? event
-        : instance.template.getEventTemplateByName(event);
+        : instance?.template.getEventTemplateByName(event);
 
     if (et == null)
       return AsyncReply<dynamic>().triggerError(new AsyncException(
@@ -192,13 +205,17 @@ class DistributedResource extends IResource {
       return AsyncReply().triggerError(new AsyncException(
           ErrorType.Management, ExceptionCode.NotListenable.index, ""));
 
-    return _connection.sendListenRequest(_instanceId, et.index);
+    return _connection?.sendListenRequest(_instanceId as int, et.index)
+        as AsyncReply;
   }
 
   AsyncReply<dynamic> unlisten(event) {
-    EventTemplate et = event is EventTemplate
+    if (_destroyed) throw new Exception("Trying to access destroyed object");
+    if (_suspended) throw new Exception("Trying to access suspended object");
+
+    EventTemplate? et = event is EventTemplate
         ? event
-        : instance.template.getEventTemplateByName(event);
+        : instance?.template.getEventTemplateByName(event);
 
     if (et == null)
       return AsyncReply().triggerError(new AsyncException(
@@ -208,48 +225,60 @@ class DistributedResource extends IResource {
       return AsyncReply().triggerError(new AsyncException(
           ErrorType.Management, ExceptionCode.NotListenable.index, ""));
 
-    return connection.sendUnlistenRequest(_instanceId, et.index);
+    return connection?.sendUnlistenRequest(_instanceId as int, et.index)
+        as AsyncReply;
   }
 
   void internal_emitEventByIndex(int index, dynamic args) {
     // neglect events when the object is not yet attached
     if (!_attached) return;
 
-    var et = instance.template.getEventTemplateByIndex(index);
+    var et = instance?.template.getEventTemplateByIndex(index);
+    if (et != null) {
       emitArgs(et.name, [args]);
-    //emitArgs(event, arguments)
-    instance.emitResourceEvent(null, null, et.name, args);
+      instance?.emitResourceEvent(null, null, et.name, args);
+    }
   }
 
-  AsyncReply<dynamic> internal_invokeByNamedArguments(int index, Structure namedArgs) {
+  AsyncReply<dynamic> internal_invokeByNamedArguments(
+      int index, Structure namedArgs) {
+    if (_destroyed) throw new Exception("Trying to access destroyed object");
+    if (_suspended) throw new Exception("Trying to access suspended object");
+
+    if (instance == null) throw Exception("Object not initialized.");
+
+    var ins = instance as Instance;
+
+    if (index >= ins.template.functions.length)
+      throw new Exception("Function index is incorrect");
+
+    return connection?.sendInvokeByNamedArguments(
+        _instanceId as int, index, namedArgs) as AsyncReply<dynamic>;
+  }
+
+  AsyncReply<dynamic> internal_invokeByArrayArguments(
+      int index, List<dynamic> args) {
     if (_destroyed) throw new Exception("Trying to access destroyed object");
 
     if (_suspended) throw new Exception("Trying to access suspended object");
+    if (instance == null) throw Exception("Object not initialized.");
 
-    if (index >= instance.template.functions.length)
+    var ins = instance as Instance;
+
+    if (index >= ins.template.functions.length)
       throw new Exception("Function index is incorrect");
 
-    return connection.sendInvokeByNamedArguments(_instanceId, index, namedArgs);
-  }
-
-  AsyncReply<dynamic> internal_invokeByArrayArguments(int index, List<dynamic> args) {
-    if (_destroyed) throw new Exception("Trying to access destroyed object");
-
-    if (_suspended) throw new Exception("Trying to access suspended object");
-
-    if (index >= instance.template.functions.length)
-      throw new Exception("Function index is incorrect");
-
-    return connection.sendInvokeByArrayArguments(_instanceId, index, args);
+    return _connection?.sendInvokeByArrayArguments(
+        _instanceId as int, index, args) as AsyncReply;
   }
 
   operator [](String index) {
-    var pt = instance.template.getPropertyTemplateByName(index);
+    var pt = instance?.template.getPropertyTemplateByName(index);
     if (pt != null) return get(pt.index);
   }
 
   operator []=(String index, value) {
-    var pt = instance.template.getPropertyTemplateByName(index);
+    var pt = instance?.template.getPropertyTemplateByName(index);
     if (pt != null) set(pt.index, value);
   }
 
@@ -266,7 +295,7 @@ class DistributedResource extends IResource {
     var memberName = _getMemberName(invocation.memberName);
 
     if (invocation.isMethod) {
-      var ft = instance.template.getFunctionTemplateByName(memberName);
+      var ft = instance?.template.getFunctionTemplateByName(memberName);
 
       if (_attached && ft != null) {
         if (invocation.namedArguments.length > 0) {
@@ -281,14 +310,14 @@ class DistributedResource extends IResource {
         }
       }
     } else if (invocation.isSetter) {
-      var pt = instance.template.getPropertyTemplateByName(memberName);
+      var pt = instance?.template.getPropertyTemplateByName(memberName);
 
       if (pt != null) {
         set(pt.index, invocation.positionalArguments[0]);
         return true;
       }
     } else if (invocation.isGetter) {
-      var pt = instance.template.getPropertyTemplateByName(memberName);
+      var pt = instance?.template.getPropertyTemplateByName(memberName);
 
       if (pt != null) {
         return get(pt.index);
@@ -304,7 +333,9 @@ class DistributedResource extends IResource {
   /// <param name="index">Zero-based property index.</param>
   /// <returns>Value</returns>
   get(int index) {
-    if (index >= _properties.length) return null;
+    //if (_properties == null) return null;
+    //var props = _properties as List;
+    //if (index >= props.length) return null;
     return _properties[index];
   }
 
@@ -312,9 +343,12 @@ class DistributedResource extends IResource {
     if (!_attached) {
       _queued_updates.add(KeyValuePair(index, value));
     } else {
-      var pt = instance.template.getPropertyTemplateByIndex(index);
+      var pt = instance?.template.getPropertyTemplateByIndex(index);
+
+      if (pt != null) {
         _properties[index] = value;
-      instance.emitModification(pt, value);
+        instance?.emitModification(pt, value);
+      }
     }
   }
 
@@ -325,18 +359,19 @@ class DistributedResource extends IResource {
   /// <param name="value">Value</param>
   /// <returns>Indicator when the property is set.</returns>
   AsyncReply<dynamic> set(int index, dynamic value) {
-    if (index >= _properties.length) return null;
+    if (index >= _properties.length)
+      throw Exception("Property with index `${index}` not found.");
 
     var reply = new AsyncReply<dynamic>();
+    var con = _connection as DistributedConnection;
 
-    var parameters = Codec.compose(value, connection);
-    connection
-        .sendRequest(IIPPacketAction.SetProperty)
-        .addUint32(_instanceId)
-        .addUint8(index)
-        .addDC(parameters)
+    var parameters = Codec.compose(value, con);
+    (con.sendRequest(IIPPacketAction.SetProperty)
+          ..addUint32(_instanceId as int)
+          ..addUint8(index)
+          ..addDC(parameters))
         .done()
-        .then((res) {
+          ..then((res) {
             // not really needed, server will always send property modified,
             // this only happens if the programmer forgot to emit in property setter
             _properties[index] = value;

lib/src/Net/IIP/DistributedServer.dart

@@ -17,7 +17,7 @@ class DistributedServer extends IResource {
     return AsyncReply.ready(true);
   }
 
-  EntryPoint entryPoint;
+  EntryPoint? entryPoint;
 
   @override
   getProperty(String name) => null;

lib/src/Net/NetworkBuffer.dart

@@ -25,35 +25,25 @@ SOFTWARE.
 import '../Data/DC.dart';
 import 'dart:core';
 
-class NetworkBuffer
-{
-    DC _data;
+class NetworkBuffer {
+  DC _data = new DC(0);
 
   int _neededDataLength = 0;
 
-    NetworkBuffer()
-    {
-        _data = new DC(0);
-    }
+  NetworkBuffer() {}
 
   bool get protected => _neededDataLength > _data.length;
 
   int get available => _data.length;
 
-
-
-    void holdForNextWrite(DC src, int offset, int size)
-    {
+  void holdForNextWrite(DC src, int offset, int size) {
     holdFor(src, offset, size, size + 1);
   }
 
-
-    void holdFor(DC src, int offset, int size, int needed)
-    {
+  void holdFor(DC src, int offset, int size, int needed) {
     //lock (syncLock)
     //{
-            if (size >= needed)
-                throw new Exception("Size >= Needed !");
+    if (size >= needed) throw new Exception("Size >= Needed !");
 
     //trim = true;
     _data = DC.combine(src, offset, size, _data, 0, _data.length);
@@ -62,68 +52,50 @@ class NetworkBuffer
     //}
   }
 
-    void holdForNeeded(DC src, int needed)
-    {
+  void holdForNeeded(DC src, int needed) {
     holdFor(src, 0, src.length, needed);
   }
 
-    bool protect(DC data, int offset, int needed)
-    {
+  bool protect(DC data, int offset, int needed) {
     int dataLength = _data.length - offset;
 
     // protection
-        if (dataLength < needed)
-        {
+    if (dataLength < needed) {
       holdFor(data, offset, dataLength, needed);
       return true;
-        }
-        else
+    } else
       return false;
   }
 
-
-
-    void write(DC src, int offset, int length)
-    {
+  void write(DC src, int offset, int length) {
     //lock(syncLock)
     _data.append(src, offset, length);
   }
 
-    bool get canRead
-    {
-        if (_data.length == 0)
-            return false;
-        if (_data.length < _neededDataLength)
-            return false;
+  bool get canRead {
+    if (_data.length == 0) return false;
+    if (_data.length < _neededDataLength) return false;
 
     return true;
   }
 
-    DC read()
-    {
+  DC? read() {
     //lock (syncLock)
     //{
-        if (_data.length == 0)
-            return null;
+    if (_data.length == 0) return null;
 
-        DC rt = null;
+    DC? rt = null;
 
-        if (_neededDataLength == 0)
-        {
+    if (_neededDataLength == 0) {
       rt = _data;
       _data = new DC(0);
-        }
-        else
-        {
-            if (_data.length >= _neededDataLength)
-            {
+    } else {
+      if (_data.length >= _neededDataLength) {
         rt = _data;
         _data = new DC(0);
         _neededDataLength = 0;
         return rt;
-            }
-            else
-            {
+      } else {
         return null;
       }
     }

lib/src/Net/NetworkConnection.dart

@@ -32,9 +32,9 @@ import '../Data/DC.dart';
 import 'Sockets/IPEndPoint.dart';
 
 class NetworkConnection extends IDestructible with INetworkReceiver<ISocket> {
-  ISocket _sock;
+  ISocket? _sock;
 
-  DateTime _lastAction;
+  DateTime _lastAction = DateTime.now();
 
   //public delegate void DataReceivedEvent(NetworkConnection sender, NetworkBuffer data);
   //public delegate void ConnectionClosedEvent(NetworkConnection sender);
@@ -48,7 +48,6 @@ class NetworkConnection extends IDestructible with INetworkReceiver<ISocket> {
 
   bool _processing = false;
 
-
   void destroy() {
     // if (connected)
     close();
@@ -58,7 +57,7 @@ class NetworkConnection extends IDestructible with INetworkReceiver<ISocket> {
 
   NetworkConnection() {}
 
-  ISocket get socket => _sock;
+  ISocket? get socket => _sock;
 
   void assign(ISocket socket) {
     _lastAction = DateTime.now();
@@ -71,14 +70,14 @@ class NetworkConnection extends IDestructible with INetworkReceiver<ISocket> {
     //socket.on("connect", socket_OnConnect);
   }
 
-  ISocket unassign() {
+  ISocket? unassign() {
     if (_sock != null) {
       // connected = false;
       // _sock.off("close", socket_OnClose);
       // _sock.off("connect", socket_OnConnect);
       // _sock.off("receive", socket_OnReceive);
 
-      _sock.receiver = null;
+      _sock?.receiver = null;
       var rt = _sock;
       _sock = null;
 
@@ -92,17 +91,13 @@ class NetworkConnection extends IDestructible with INetworkReceiver<ISocket> {
     emitArgs("dataReceived", [data]);
   }
 
-  void connected(){
+  void connected() {}
 
-  }
-
-  void disconnected(){
-
-  }
+  void disconnected() {}
 
   void close() {
     try {
-      if (_sock != null) _sock.close();
+      if (_sock != null) _sock?.close();
     } catch (ex) {
       //Global.Log("NetworkConenction:Close", LogType.Error, ex.ToString());
 
@@ -111,17 +106,17 @@ class NetworkConnection extends IDestructible with INetworkReceiver<ISocket> {
 
   DateTime get lastAction => _lastAction;
 
-  IPEndPoint get remoteEndPoint => _sock?.remoteEndPoint;
+  IPEndPoint? get remoteEndPoint => _sock?.remoteEndPoint;
 
-  IPEndPoint get localEndPoint => _sock?.localEndPoint;
+  IPEndPoint? get localEndPoint => _sock?.localEndPoint;
 
-  bool get isConnected => _sock.state == SocketState.Established;
+  bool get isConnected => _sock?.state == SocketState.Established;
 
   void send(DC msg) {
     try {
       if (_sock != null) {
         _lastAction = DateTime.now();
-        _sock.send(msg);
+        _sock?.send(msg);
       }
     } catch (ex) {
       //Console.WriteLine(ex.ToString());
@@ -151,8 +146,8 @@ class NetworkConnection extends IDestructible with INetworkReceiver<ISocket> {
       if (_sock == null) return;
 
       // Closed ?
-      if (_sock.state == SocketState.Closed ||
-          _sock.state == SocketState.Terminated) // || !connected)
+      if (_sock?.state == SocketState.Closed ||
+          _sock?.state == SocketState.Terminated) // || !connected)
         return;
 
       _lastAction = DateTime.now();

lib/src/Net/Packets/IIPAuthPacket.dart

@@ -26,84 +26,73 @@ import 'IIPAuthPacketAction.dart';
 import 'IIPAuthPacketCommand.dart';
 import '../../Security/Authority/AuthenticationMethod.dart';
 
-class IIPAuthPacket
-{
+class IIPAuthPacket {
+  int command = 0;
+  int action = 0;
 
-    int command;
-    int action;
+  int errorCode = 0;
+  String errorMessage = "";
 
-    int errorCode;
-    String errorMessage;
+  AuthenticationMethod localMethod = AuthenticationMethod.None;
 
-    AuthenticationMethod localMethod;
+  DC? sourceInfo;
 
-    DC sourceInfo;
+  DC? hash;
 
-    DC hash;
+  DC? sessionId;
 
-    DC sessionId;
+  AuthenticationMethod remoteMethod = AuthenticationMethod.None;
 
-    AuthenticationMethod remoteMethod;
+  String? domain;
 
-    String domain;
+  int certificateId = 0;
 
-    int certificateId;
+  String? localUsername;
 
-    String localUsername;
+  String? remoteUsername;
 
-    String remoteUsername;
+  DC? localPassword;
 
-    DC localPassword;
+  DC? remotePassword;
 
-    DC remotePassword;
+  DC? localToken;
 
-    DC localToken;
+  DC? remoteToken;
 
-    DC remoteToken;
+  DC? asymetricEncryptionKey;
 
-    DC asymetricEncryptionKey;
+  DC? localNonce;
 
-    DC localNonce;
+  DC? remoteNonce;
 
-    DC remoteNonce;
+  int remoteTokenIndex = 0;
 
-    int remoteTokenIndex;
+  int _dataLengthNeeded = 0;
 
-    int _dataLengthNeeded;
-
-    bool _notEnough(int offset, int ends, int needed)
-    {
-        if (offset + needed > ends)
-        {
+  bool _notEnough(int offset, int ends, int needed) {
+    if (offset + needed > ends) {
       _dataLengthNeeded = needed - (ends - offset);
       return true;
-        }
-        else
+    } else
       return false;
   }
 
-    toString()
-    {
+  toString() {
     return command.toString() + " " + action.toString();
   }
 
-    int parse(DC data, int offset, int ends)
-    {
+  int parse(DC data, int offset, int ends) {
     var oOffset = offset;
 
-        if (_notEnough(offset, ends, 1))
-            return -_dataLengthNeeded;
+    if (_notEnough(offset, ends, 1)) return -_dataLengthNeeded;
 
     command = (data[offset] >> 6);
 
-        if (command == IIPAuthPacketCommand.Action)
-        {
+    if (command == IIPAuthPacketCommand.Action) {
       action = (data[offset++] & 0x3f);
 
-            if (action == IIPAuthPacketAction.AuthenticateHash)
-            {
-                if (_notEnough(offset, ends, 32))
-                    return -_dataLengthNeeded;
+      if (action == IIPAuthPacketAction.AuthenticateHash) {
+        if (_notEnough(offset, ends, 32)) return -_dataLengthNeeded;
 
         hash = data.clip(offset, 32);
 
@@ -112,18 +101,14 @@ class IIPAuthPacket
         //Hash = hash;
 
         offset += 32;
-            }
-            else if (action == IIPAuthPacketAction.NewConnection)
-            {
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPAuthPacketAction.NewConnection) {
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         var length = data.getUint16(offset);
 
         offset += 2;
 
-                if (_notEnough(offset, ends, length))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, length)) return -_dataLengthNeeded;
 
         sourceInfo = data.clip(offset, length);
 
@@ -132,14 +117,11 @@ class IIPAuthPacket
         //SourceInfo = sourceInfo;
 
         offset += 32;
-            }
-            else if (action == IIPAuthPacketAction.ResumeConnection
-                  || action == IIPAuthPacketAction.ConnectionEstablished)
-            {
+      } else if (action == IIPAuthPacketAction.ResumeConnection ||
+          action == IIPAuthPacketAction.ConnectionEstablished) {
         //var sessionId = new byte[32];
 
-                if (_notEnough(offset, ends, 32))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, 32)) return -_dataLengthNeeded;
 
         sessionId = data.clip(offset, 32);
 
@@ -148,20 +130,15 @@ class IIPAuthPacket
 
         offset += 32;
       }
-        }
-        else if (command == IIPAuthPacketCommand.Declare)
-        {
+    } else if (command == IIPAuthPacketCommand.Declare) {
       remoteMethod = AuthenticationMethod.values[((data[offset] >> 4) & 0x3)];
       localMethod = AuthenticationMethod.values[((data[offset] >> 2) & 0x3)];
       var encrypt = ((data[offset++] & 0x2) == 0x2);
 
-
-            if (_notEnough(offset, ends, 1))
-                return -_dataLengthNeeded;
+      if (_notEnough(offset, ends, 1)) return -_dataLengthNeeded;
 
       var domainLength = data[offset++];
-            if (_notEnough(offset, ends, domainLength))
-                return -_dataLengthNeeded;
+      if (_notEnough(offset, ends, domainLength)) return -_dataLengthNeeded;
 
       var domain = data.getString(offset, domainLength);
 
@@ -169,14 +146,9 @@ class IIPAuthPacket
 
       offset += domainLength;
 
-
-            if (remoteMethod == AuthenticationMethod.Credentials)
-            {
-                if (localMethod == AuthenticationMethod.None)
-                {
-                    if (_notEnough(offset, ends, 33))
-                        return -_dataLengthNeeded;
-
+      if (remoteMethod == AuthenticationMethod.Credentials) {
+        if (localMethod == AuthenticationMethod.None) {
+          if (_notEnough(offset, ends, 33)) return -_dataLengthNeeded;
 
           remoteNonce = data.clip(offset, 32);
 
@@ -184,21 +156,15 @@ class IIPAuthPacket
 
           var length = data[offset++];
 
-                    if (_notEnough(offset, ends, length))
-                        return -_dataLengthNeeded;
+          if (_notEnough(offset, ends, length)) return -_dataLengthNeeded;
 
           remoteUsername = data.getString(offset, length);
 
-                      
           offset += length;
         }
-            }
-            else if (remoteMethod == AuthenticationMethod.Token)
-            {
-                if (localMethod == AuthenticationMethod.None)
-                {
-                    if (_notEnough(offset, ends, 40))
-                            return -_dataLengthNeeded;
+      } else if (remoteMethod == AuthenticationMethod.Token) {
+        if (localMethod == AuthenticationMethod.None) {
+          if (_notEnough(offset, ends, 40)) return -_dataLengthNeeded;
 
           remoteNonce = data.clip(offset, 32);
 
@@ -209,93 +175,66 @@ class IIPAuthPacket
         }
       }
 
-
-        
-            if (encrypt)
-            {
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+      if (encrypt) {
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         var keyLength = data.getUint16(offset);
 
         offset += 2;
 
-                if (_notEnough(offset, ends, keyLength))
-                    return -_dataLengthNeeded;
-
+        if (_notEnough(offset, ends, keyLength)) return -_dataLengthNeeded;
 
         asymetricEncryptionKey = data.clip(offset, keyLength);
 
         offset += keyLength;
       }
-        }
-        else if (command == IIPAuthPacketCommand.Acknowledge)
-        {
-            remoteMethod  = AuthenticationMethod.values[ ((data[offset] >> 4) & 0x3)];
-            localMethod = AuthenticationMethod.values[ ((data[offset] >> 2) & 0x3)];
+    } else if (command == IIPAuthPacketCommand.Acknowledge) {
+      remoteMethod = AuthenticationMethod.values[((data[offset] >> 4) & 0x3)];
+      localMethod = AuthenticationMethod.values[((data[offset] >> 2) & 0x3)];
       var encrypt = ((data[offset++] & 0x2) == 0x2);
 
-            if (remoteMethod == AuthenticationMethod.None)
-            {
-                if (localMethod == AuthenticationMethod.None)
-                {
+      if (remoteMethod == AuthenticationMethod.None) {
+        if (localMethod == AuthenticationMethod.None) {
           // do nothing
         }
-            }
-            else if (remoteMethod == AuthenticationMethod.Credentials
-              || remoteMethod == AuthenticationMethod.Token)
-            {
-                if (localMethod == AuthenticationMethod.None)
-                {
-                    if (_notEnough(offset, ends, 32))
-                        return -_dataLengthNeeded;
+      } else if (remoteMethod == AuthenticationMethod.Credentials ||
+          remoteMethod == AuthenticationMethod.Token) {
+        if (localMethod == AuthenticationMethod.None) {
+          if (_notEnough(offset, ends, 32)) return -_dataLengthNeeded;
 
           remoteNonce = data.clip(offset, 32);
           offset += 32;
-
         }
       }
 
-            if (encrypt)
-            {
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+      if (encrypt) {
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         var keyLength = data.getUint16(offset);
 
         offset += 2;
 
-                if (_notEnough(offset, ends, keyLength))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, keyLength)) return -_dataLengthNeeded;
 
         asymetricEncryptionKey = data.clip(offset, keyLength);
 
         offset += keyLength;
       }
-        }
-        else if (command == IIPAuthPacketCommand.Error)
-        {
-            if (_notEnough(offset, ends, 4))
-                return -_dataLengthNeeded;
+    } else if (command == IIPAuthPacketCommand.Error) {
+      if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
       offset++;
       errorCode = data[offset++];
 
-
       var cl = data.getUint16(offset);
       offset += 2;
 
-            if (_notEnough(offset, ends, cl))
-                return -_dataLengthNeeded;
+      if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
       errorMessage = data.getString(offset, cl);
       offset += cl;
-
     }
 
-
     return offset - oOffset;
-
   }
-
 }

lib/src/Net/Packets/IIPPacket.dart

@@ -31,181 +31,136 @@ import 'IIPPacketReport.dart';
 import '../../Data/Codec.dart';
 import '../../Data/DataType.dart';
 
-class IIPPacket
-{
+class IIPPacket {
+  int report = 0;
 
+  int command = 0;
 
+  int action = 0;
 
+  int event = 0;
 
+  int previousCommand = 0;
 
+  int previousAction = 0;
 
-    int report;
+  int previousEvent = 0;
 
-    int command;
+  int resourceId = 0;
+  int newResourceId = 0;
 
-    int action;
+  int childId = 0;
+  int storeId = 0;
 
-    int event;
+  int resourceAge = 0;
+  DC content = DC(0);
+  int errorCode = 0;
+  String errorMessage = "";
+  String className = "";
+  String resourceLink = "";
+  Guid classId = Guid(DC(0));
+  int methodIndex = 0;
+  String methodName = "";
+  int callbackId = 0;
+  int progressValue = 0;
+  int progressMax = 0;
+  DateTime fromDate = DateTime(2000);
+  DateTime toDate = DateTime(2000);
+  int fromAge = 0;
+  int toAge = 0;
 
-    int previousCommand;
+  int _dataLengthNeeded = 0;
+  int _originalOffset = 0;
 
-
-    int previousAction;
-
-    int previousEvent;
-
-
-    int resourceId;
-    int newResourceId;
-
-    int childId;
-    int storeId;
-
-    int resourceAge;
-    DC content;
-    int errorCode;
-    String errorMessage;
-    String className ;
-    String resourceLink ;
-    Guid classId ;
-    int methodIndex ;
-    String methodName;
-    int callbackId ;
-    int progressValue;
-    int progressMax ;
-    DateTime fromDate ;
-    DateTime toDate;
-    int fromAge;
-    int toAge;
-
-    int _dataLengthNeeded;
-    int _originalOffset;
-
-
-    bool _notEnough(int offset, int ends, int needed)
-    {
-        if (offset + needed > ends)
-        {
+  bool _notEnough(int offset, int ends, int needed) {
+    if (offset + needed > ends) {
       _dataLengthNeeded = needed - (ends - offset);
       //_dataLengthNeeded = (needed - (ends - offset)) + (offset - _originalOffset);
 
       return true;
-        }
-        else
+    } else
       return false;
   }
 
-    int parse(DC data, int offset, int ends)
-    {
+  int parse(DC data, int offset, int ends) {
     _originalOffset = offset;
 
-        if (_notEnough(offset, ends, 1))
-            return -_dataLengthNeeded;
+    if (_notEnough(offset, ends, 1)) return -_dataLengthNeeded;
 
     previousCommand = command;
 
     command = (data[offset] >> 6);
 
-        if (command == IIPPacketCommand.Event)
-        {
+    if (command == IIPPacketCommand.Event) {
       event = (data[offset++] & 0x3f);
 
-            if (_notEnough(offset, ends, 4))
-                return -_dataLengthNeeded;
+      if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
       resourceId = data.getUint32(offset);
       offset += 4;
-        }
-        else if (command == IIPPacketCommand.Report)
-        {
+    } else if (command == IIPPacketCommand.Report) {
       report = (data[offset++] & 0x3f);
 
-            if (_notEnough(offset, ends, 4))
-                return -_dataLengthNeeded;
+      if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
       callbackId = data.getUint32(offset);
       offset += 4;
-        }
-        else
-        {
+    } else {
       previousAction = action;
       action = (data[offset++] & 0x3f);
 
-            if (_notEnough(offset, ends, 4))
-                return -_dataLengthNeeded;
+      if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
       callbackId = data.getUint32(offset);
       offset += 4;
     }
 
-        if (command == IIPPacketCommand.Event)
-        {
-            if (event == IIPPacketEvent.ResourceReassigned)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+    if (command == IIPPacketCommand.Event) {
+      if (event == IIPPacketEvent.ResourceReassigned) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
-                newResourceId = data.getUint32( offset);
+        newResourceId = data.getUint32(offset);
         offset += 4;
-
-            }
-            else if (event == IIPPacketEvent.ResourceDestroyed)
-            {
+      } else if (event == IIPPacketEvent.ResourceDestroyed) {
         // nothing to parse
-            }
-            else if (event == IIPPacketEvent.ChildAdded
-                    || event == IIPPacketEvent.ChildRemoved)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+      } else if (event == IIPPacketEvent.ChildAdded ||
+          event == IIPPacketEvent.ChildRemoved) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         childId = data.getUint32(offset);
         offset += 4;
-            }
-            else if(event == IIPPacketEvent.Renamed)
-            {
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+      } else if (event == IIPPacketEvent.Renamed) {
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         var cl = data.getUint16(offset);
         offset += 2;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         content = data.clip(offset, cl);
 
         offset += cl;
-            }
-            else if (event == IIPPacketEvent.PropertyUpdated
-                    || event == IIPPacketEvent.EventOccurred)
-            {
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+      } else if (event == IIPPacketEvent.PropertyUpdated ||
+          event == IIPPacketEvent.EventOccurred) {
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         methodIndex = data[offset++];
 
         var dt = data[offset++];
         var size = DataType.size(dt);
 
-                if (size < 0)
-                {
-                    if (_notEnough(offset, ends, 4))
-                        return -_dataLengthNeeded;
+        if (size < 0) {
+          if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
-                    var cl = data.getUint32( offset);
+          var cl = data.getUint32(offset);
           offset += 4;
 
-                    if (_notEnough(offset, ends, cl))
-                        return -_dataLengthNeeded;
+          if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
-                    content = data.clip( offset - 5, cl + 5);
+          content = data.clip(offset - 5, cl + 5);
           offset += cl;
-                }
-                else
-                {
-                    if (_notEnough(offset, ends, size))
-                        return -_dataLengthNeeded;
+        } else {
+          if (_notEnough(offset, ends, size)) return -_dataLengthNeeded;
 
           content = data.clip(offset - 1, size + 1);
           offset += size;
@@ -229,57 +184,39 @@ class IIPPacket
 
       // }
       // Attribute
-            else if (event == IIPPacketEvent.AttributesUpdated)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+      else if (event == IIPPacketEvent.AttributesUpdated) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         var cl = data.getUint32(offset);
         offset += 4;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         content = data.clip(offset, cl);
 
         offset += cl;
       }
-        }
-        else if (command == IIPPacketCommand.Request)
-        {
-            if (action == IIPPacketAction.AttachResource)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+    } else if (command == IIPPacketCommand.Request) {
+      if (action == IIPPacketAction.AttachResource) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
-            }
-            else if (action == IIPPacketAction.ReattachResource)
-            {
-                if (_notEnough(offset, ends, 12))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.ReattachResource) {
+        if (_notEnough(offset, ends, 12)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
 
         resourceAge = data.getUint64(offset);
         offset += 8;
-
-            }
-            else if (action == IIPPacketAction.DetachResource)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.DetachResource) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
-
-            }
-            else if (action == IIPPacketAction.CreateResource)
-            {
-                if (_notEnough(offset, ends, 12))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.CreateResource) {
+        if (_notEnough(offset, ends, 12)) return -_dataLengthNeeded;
 
         storeId = data.getUint32(offset);
         offset += 4;
@@ -289,106 +226,72 @@ class IIPPacket
         var cl = data.getUint32(offset);
         offset += 4;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         content = data.clip(offset, cl);
-            }
-            else if (action == IIPPacketAction.DeleteResource)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.DeleteResource) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
-
-            }
-            else if (action == IIPPacketAction.AddChild
-                    || action == IIPPacketAction.RemoveChild)
-            {
-                if (_notEnough(offset, ends, 8))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.AddChild ||
+          action == IIPPacketAction.RemoveChild) {
+        if (_notEnough(offset, ends, 8)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
         childId = data.getUint32(offset);
         offset += 4;
-            }
-            else if (action == IIPPacketAction.RenameResource)
-            {
-                if (_notEnough(offset, ends, 6))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.RenameResource) {
+        if (_notEnough(offset, ends, 6)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
         var cl = data.getUint16(offset);
         offset += 2;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         content = data.clip(offset, cl);
         offset += cl;
-            }
-            else if (action == IIPPacketAction.TemplateFromClassName)
-            {
-                if (_notEnough(offset, ends, 1))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.TemplateFromClassName) {
+        if (_notEnough(offset, ends, 1)) return -_dataLengthNeeded;
 
         var cl = data[offset++];
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         className = data.getString(offset, cl);
         offset += cl;
-
-            }
-            else if (action == IIPPacketAction.TemplateFromClassId)
-            {
-                if (_notEnough(offset, ends, 16))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.TemplateFromClassId) {
+        if (_notEnough(offset, ends, 16)) return -_dataLengthNeeded;
 
         classId = data.getGuid(offset);
         offset += 16;
-
-            }
-            else if (action == IIPPacketAction.TemplateFromResourceId)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.TemplateFromResourceId) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
-            }
-            else if (action == IIPPacketAction.QueryLink
-                    || action == IIPPacketAction.LinkTemplates)
-            {
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.QueryLink ||
+          action == IIPPacketAction.LinkTemplates) {
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         var cl = data.getUint16(offset);
         offset += 2;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         resourceLink = data.getString(offset, cl);
         offset += cl;
-            }
-            else if (action == IIPPacketAction.ResourceChildren
-                    || action == IIPPacketAction.ResourceParents)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.ResourceChildren ||
+          action == IIPPacketAction.ResourceParents) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
-            }
-            else if (action == IIPPacketAction.ResourceHistory)
-            {
-                if (_notEnough(offset, ends, 20))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.ResourceHistory) {
+        if (_notEnough(offset, ends, 20)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
@@ -398,13 +301,9 @@ class IIPPacket
 
         toDate = data.getDateTime(offset);
         offset += 8;
-
-            }
-            else if (action == IIPPacketAction.InvokeFunctionArrayArguments
-                    || action == IIPPacketAction.InvokeFunctionNamedArguments)
-            {
-                if (_notEnough(offset, ends, 9))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.InvokeFunctionArrayArguments ||
+          action == IIPPacketAction.InvokeFunctionNamedArguments) {
+        if (_notEnough(offset, ends, 9)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
@@ -414,18 +313,13 @@ class IIPPacket
         var cl = data.getUint32(offset);
         offset += 4;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         content = data.clip(offset, cl);
         offset += cl;
-
-            }
-            else if (action == IIPPacketAction.Listen 
-                  || action == IIPPacketAction.Unlisten)
-            {
-                if (_notEnough(offset, ends, 5))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.Listen ||
+          action == IIPPacketAction.Unlisten) {
+        if (_notEnough(offset, ends, 5)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
@@ -457,72 +351,55 @@ class IIPPacket
       //     offset += 8;
 
       // }
-            else if (action == IIPPacketAction.SetProperty)
-            {
-                if (_notEnough(offset, ends, 6))
-                    return -_dataLengthNeeded;
+      else if (action == IIPPacketAction.SetProperty) {
+        if (_notEnough(offset, ends, 6)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
 
         methodIndex = data[offset++];
 
-
         var dt = data[offset++];
         var size = DataType.size(dt);
 
-                if (size < 0)
-                {
-                    if (_notEnough(offset, ends, 4))
-                        return -_dataLengthNeeded;
+        if (size < 0) {
+          if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
           var cl = data.getUint32(offset);
           offset += 4;
 
-                    if (_notEnough(offset, ends, cl))
-                        return -_dataLengthNeeded;
+          if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
-                    content = data.clip(offset-5, cl + 5);
+          content = data.clip(offset - 5, cl + 5);
           offset += cl;
-                }
-                else
-                {
-                    if (_notEnough(offset, ends, size))
-                        return -_dataLengthNeeded;
+        } else {
+          if (_notEnough(offset, ends, size)) return -_dataLengthNeeded;
 
-                    content = data.clip(offset-1, size + 1);
+          content = data.clip(offset - 1, size + 1);
           offset += size;
         }
       }
       // Attributes
-            else if (action == IIPPacketAction.UpdateAllAttributes
-                    || action == IIPPacketAction.GetAttributes
-                    || action == IIPPacketAction.UpdateAttributes
-                    || action == IIPPacketAction.ClearAttributes)
-            {
-                if (_notEnough(offset, ends, 8))
-                    return -_dataLengthNeeded;
+      else if (action == IIPPacketAction.UpdateAllAttributes ||
+          action == IIPPacketAction.GetAttributes ||
+          action == IIPPacketAction.UpdateAttributes ||
+          action == IIPPacketAction.ClearAttributes) {
+        if (_notEnough(offset, ends, 8)) return -_dataLengthNeeded;
 
         resourceId = data.getUint32(offset);
         offset += 4;
         var cl = data.getUint32(offset);
         offset += 4;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         content = data.clip(offset, cl);
         offset += cl;
       }
-        }
-        else if (command == IIPPacketCommand.Reply)
-        {
-            if (action == IIPPacketAction.AttachResource
-                || action == IIPPacketAction.ReattachResource)
-            {
-
-                if (_notEnough(offset, ends, 26))
-                    return -_dataLengthNeeded;
+    } else if (command == IIPPacketCommand.Reply) {
+      if (action == IIPPacketAction.AttachResource ||
+          action == IIPPacketAction.ReattachResource) {
+        if (_notEnough(offset, ends, 26)) return -_dataLengthNeeded;
 
         classId = data.getGuid(offset);
         offset += 16;
@@ -533,176 +410,132 @@ class IIPPacket
         var cl = data.getUint16(offset);
         offset += 2;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         resourceLink = data.getString(offset, cl);
         offset += cl;
 
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         cl = data.getUint32(offset);
         offset += 4;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         content = data.clip(offset, cl);
         offset += cl;
-            }
-            else if (action == IIPPacketAction.DetachResource)
-            {
+      } else if (action == IIPPacketAction.DetachResource) {
         // nothing to do
-            }
-            else if (action == IIPPacketAction.CreateResource)
-            {
-                if (_notEnough(offset, ends, 20))
-                    return -_dataLengthNeeded;
+      } else if (action == IIPPacketAction.CreateResource) {
+        if (_notEnough(offset, ends, 20)) return -_dataLengthNeeded;
 
         //ClassId = data.GetGuid(offset);
         //offset += 16;
 
         resourceId = data.getUint32(offset);
         offset += 4;
-
-            }
-            else if (action == IIPPacketAction.DetachResource)
-            {
+      } else if (action == IIPPacketAction.DetachResource) {
         // nothing to do
       }
       // Inquire
-            else if (action == IIPPacketAction.TemplateFromClassName
-                    || action == IIPPacketAction.TemplateFromClassId
-                    || action == IIPPacketAction.TemplateFromResourceId
-                    || action == IIPPacketAction.QueryLink
-                    || action == IIPPacketAction.ResourceChildren
-                    || action == IIPPacketAction.ResourceParents
-                    || action == IIPPacketAction.ResourceHistory
-                    || action == IIPPacketAction.LinkTemplates
+      else if (action == IIPPacketAction.TemplateFromClassName ||
+          action == IIPPacketAction.TemplateFromClassId ||
+          action == IIPPacketAction.TemplateFromResourceId ||
+          action == IIPPacketAction.QueryLink ||
+          action == IIPPacketAction.ResourceChildren ||
+          action == IIPPacketAction.ResourceParents ||
+          action == IIPPacketAction.ResourceHistory ||
+          action == IIPPacketAction.LinkTemplates
           // Attribute
-                    || action == IIPPacketAction.GetAllAttributes
-                    || action == IIPPacketAction.GetAttributes)
-            {
-                if (_notEnough(offset, ends, 4))
-                    return -_dataLengthNeeded;
+          ||
+          action == IIPPacketAction.GetAllAttributes ||
+          action == IIPPacketAction.GetAttributes) {
+        if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
         var cl = data.getUint32(offset);
         offset += 4;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         content = data.clip(offset, cl);
         offset += cl;
-            }
-            else if (action == IIPPacketAction.InvokeFunctionArrayArguments
-                || action == IIPPacketAction.InvokeFunctionNamedArguments)
+      } else if (action == IIPPacketAction.InvokeFunctionArrayArguments ||
+          action == IIPPacketAction.InvokeFunctionNamedArguments)
       //|| action == IIPPacketAction.GetProperty
       //|| action == IIPPacketAction.GetPropertyIfModified)
       {
-                if (_notEnough(offset, ends, 1))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, 1)) return -_dataLengthNeeded;
 
         var dt = data[offset++];
         var size = DataType.size(dt);
 
-                if (size < 0)
-                {
-                    if (_notEnough(offset, ends, 4))
-                        return -_dataLengthNeeded;
+        if (size < 0) {
+          if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
           var cl = data.getUint32(offset);
           offset += 4;
 
-                    if (_notEnough(offset, ends, cl))
-                        return -_dataLengthNeeded;
+          if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
           content = data.clip(offset - 5, cl + 5);
           offset += cl;
-                }
-                else
-                {
-                    if (_notEnough(offset, ends, size))
-                        return -_dataLengthNeeded;
+        } else {
+          if (_notEnough(offset, ends, size)) return -_dataLengthNeeded;
 
           content = data.clip(offset - 1, size + 1);
           offset += size;
         }
-            }
-            else if (action == IIPPacketAction.SetProperty 
-                  || action == IIPPacketAction.Listen 
-                  || action == IIPPacketAction.Unlisten)
-            {
+      } else if (action == IIPPacketAction.SetProperty ||
+          action == IIPPacketAction.Listen ||
+          action == IIPPacketAction.Unlisten) {
         // nothing to do
       }
-        }
-        else if (command == IIPPacketCommand.Report)
-        {
-            if (report == IIPPacketReport.ManagementError)
-            {
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+    } else if (command == IIPPacketCommand.Report) {
+      if (report == IIPPacketReport.ManagementError) {
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         errorCode = data.getUint16(offset);
         offset += 2;
-            }
-            else if (report == IIPPacketReport.ExecutionError)
-            {
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+      } else if (report == IIPPacketReport.ExecutionError) {
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         errorCode = data.getUint16(offset);
         offset += 2;
 
-                if (_notEnough(offset, ends, 2))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, 2)) return -_dataLengthNeeded;
 
         var cl = data.getUint16(offset);
         offset += 2;
 
-                if (_notEnough(offset, ends, cl))
-                    return -_dataLengthNeeded;
+        if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
         errorMessage = data.getString(offset, cl);
         offset += cl;
-            }
-            else if (report == IIPPacketReport.ProgressReport)
-            {
-                if (_notEnough(offset, ends, 8))
-                    return -_dataLengthNeeded;
+      } else if (report == IIPPacketReport.ProgressReport) {
+        if (_notEnough(offset, ends, 8)) return -_dataLengthNeeded;
 
         progressValue = data.getInt32(offset);
         offset += 4;
         progressMax = data.getInt32(offset);
         offset += 4;
-            }
-            else if (report == IIPPacketReport.ChunkStream)
-            {
-                if (_notEnough(offset, ends, 1))
-                    return -_dataLengthNeeded;
+      } else if (report == IIPPacketReport.ChunkStream) {
+        if (_notEnough(offset, ends, 1)) return -_dataLengthNeeded;
 
         var dt = data[offset++];
         var size = DataType.size(dt);
 
-                if (size < 0)
-                {
-                    if (_notEnough(offset, ends, 4))
-                        return -_dataLengthNeeded;
+        if (size < 0) {
+          if (_notEnough(offset, ends, 4)) return -_dataLengthNeeded;
 
           var cl = data.getUint32(offset);
           offset += 4;
 
-                    if (_notEnough(offset, ends, cl))
-                        return -_dataLengthNeeded;
+          if (_notEnough(offset, ends, cl)) return -_dataLengthNeeded;
 
           content = data.clip(offset - 5, cl + 5);
           offset += cl;
-                }
-                else
-                {
-                    if (_notEnough(offset, ends, size))
-                        return -_dataLengthNeeded;
+        } else {
+          if (_notEnough(offset, ends, size)) return -_dataLengthNeeded;
 
           content = data.clip(offset - 1, size + 1);
           offset += size;
@@ -713,34 +546,21 @@ class IIPPacket
     return offset - _originalOffset;
   }
 
-
-
-
-
-
-
-        toString()
-    {
+  toString() {
     var rt = command.toString();
 
-        if (command == IIPPacketCommand.Event)
-        {
+    if (command == IIPPacketCommand.Event) {
       rt += " " + event.toString();
-        }
-        else if (command == IIPPacketCommand.Request)
-        {
+    } else if (command == IIPPacketCommand.Request) {
       rt += " " + action.toString();
-            if (action == IIPPacketAction.AttachResource)
-            {
-                rt += " CID: " + callbackId.toString() + " RID: " + resourceId.toString(); 
+      if (action == IIPPacketAction.AttachResource) {
+        rt +=
+            " CID: " + callbackId.toString() + " RID: " + resourceId.toString();
       }
-        }
-        else if (command == IIPPacketCommand.Reply)
+    } else if (command == IIPPacketCommand.Reply)
       rt += " " + action.toString();
-        else if (command == IIPPacketCommand.Report)
-            rt += " " + report.toString();
+    else if (command == IIPPacketCommand.Report) rt += " " + report.toString();
 
     return rt;
   }
-
 }

lib/src/Net/SendList.dart

@@ -2,21 +2,16 @@ import '../Data/BinaryList.dart';
 import '../Core/AsyncReply.dart';
 import 'NetworkConnection.dart';
 
-class SendList extends BinaryList
-{
+class SendList extends BinaryList {
   NetworkConnection connection;
-    AsyncReply<List<dynamic>> reply;
+  AsyncReply<List<dynamic>>? reply;
 
-    SendList(NetworkConnection connection, AsyncReply<List<dynamic>> reply)
-    {
-        this.reply = reply;
-        this.connection = connection;
-    }
+  SendList(this.connection, this.reply) {}
 
   @override
-    AsyncReply<List<dynamic>> done()
-    {
+  AsyncReply<List<dynamic>> done() {
     connection.send(super.toDC());
-        return reply;
+
+    return reply ?? AsyncReply.ready([]);
   }
 }

lib/src/Net/Sockets/ISocket.dart

@@ -37,7 +37,7 @@ abstract class ISocket extends IDestructible {
 
   //void send(DC message);
 
-  INetworkReceiver<ISocket> receiver;
+  INetworkReceiver<ISocket>? receiver;
 
   void send(DC message, [int offset, int size]);
   void close();
@@ -45,6 +45,6 @@ abstract class ISocket extends IDestructible {
   bool begin();
 
   AsyncReply<ISocket> accept();
-  IPEndPoint remoteEndPoint;
-  IPEndPoint localEndPoint;
+  IPEndPoint? remoteEndPoint;
+  IPEndPoint? localEndPoint;
 }

lib/src/Net/Sockets/TCPSocket.dart

@@ -37,7 +37,7 @@ import 'IPEndPoint.dart';
 import '../../Core/AsyncReply.dart';
 
 class TCPSocket extends ISocket {
-  Socket sock;
+  Socket? sock;
   NetworkBuffer receiveNetworkBuffer = new NetworkBuffer();
 
   //bool asyncSending;
@@ -61,15 +61,18 @@ class TCPSocket extends ISocket {
     }
     */
 
-  IPEndPoint _localEP, _remoteEP;
+  IPEndPoint? _localEP, _remoteEP;
 
   bool begin() {
     if (began) return false;
 
     began = true;
 
-    _localEP = IPEndPoint(sock.address.rawAddress, sock.port);
-    _remoteEP = IPEndPoint(sock.remoteAddress.rawAddress, sock.remotePort);
+    if (sock != null) {
+      var s = sock as Socket;
+      _localEP = IPEndPoint(s.address.rawAddress, s.port);
+      _remoteEP = IPEndPoint(s.remoteAddress.rawAddress, s.remotePort);
+    }
     return true;
   }
 
@@ -82,7 +85,7 @@ class TCPSocket extends ISocket {
 
       var dc = new DC.fromList(data);
       receiveNetworkBuffer.write(dc, 0, dc.length);
-      receiver.networkReceive(this, receiveNetworkBuffer);
+      receiver?.networkReceive(this, receiveNetworkBuffer);
 
       //emitArgs("receive", [receiveNetworkBuffer]);
 
@@ -101,7 +104,7 @@ class TCPSocket extends ISocket {
 
   void doneHandler() {
     close();
-    sock.destroy();
+    sock?.destroy();
   }
 
   AsyncReply<bool> connect(String hostname, int port) {
@@ -134,13 +137,13 @@ class TCPSocket extends ISocket {
     return rt;
   }
 
-  IPEndPoint get localEndPoint => _localEP;
-  IPEndPoint get remoteEndPoint => _remoteEP;
+  IPEndPoint? get localEndPoint => _localEP;
+  IPEndPoint? get remoteEndPoint => _remoteEP;
 
   SocketState get state => _state;
 
-  TCPSocket.fromSocket(Socket socket) {
-    sock = socket;
+  TCPSocket.fromSocket(this.sock) {
+    //sock = socket;
     //if (socket.)
     //  _state = SocketState.Established;
   }
@@ -160,8 +163,16 @@ class TCPSocket extends ISocket {
     //emitArgs("close", []);
   }
 
-  void send(DC message, [int offset, int size]) {
-    if (state == SocketState.Established) sock.add(message.toList());
+  void send(DC message, [int? offset, int? size]) {
+    if (state == SocketState.Established) {
+      if (offset != null && size == null) {
+        sock?.add(message.clip(offset, message.length - offset).toList());
+      } else if (offset != null && size != null) {
+        sock?.add(message.clip(offset, size).toList());
+      } else {
+        sock?.add(message.toList());
+      }
+    }
   }
 
   void destroy() {

lib/src/Proxy/TemplateGenerator.dart

@@ -21,7 +21,7 @@ class TemplateGenerator {
     rt.writeln("class ${className} extends IRecord {");
 
     template.properties.forEach((p) {
-      var ptTypeName = getTypeName(template, p.valueType, templates);
+      var ptTypeName = getTypeName(template, p.valueType, templates, false);
       rt.writeln("${ptTypeName}? ${p.name};");
       rt.writeln();
     });
@@ -53,8 +53,8 @@ class TemplateGenerator {
     var descProps = template.properties.map((p) {
       var isArray = p.valueType.type & 0x80 == 0x80;
       var ptType = p.valueType.type & 0x7F;
-      var ptTypeName = getTypeName(
-          template, TemplateDataType(ptType, p.valueType.typeGuid), templates);
+      var ptTypeName = getTypeName(template,
+          TemplateDataType(ptType, p.valueType.typeGuid), templates, false);
 //      return "Prop(\"${p.name}\", ${ptTypeName}, ${isArray})";
       return "Prop('${p.name}', ${ptTypeName}, ${isArray}, ${_escape(p.readExpansion)}, ${_escape(p.writeExpansion)})";
     }).join(', ');
@@ -67,17 +67,20 @@ class TemplateGenerator {
     return rt.toString();
   }
 
-  static String _translateClassName(String className) {
+  static String _translateClassName(String className, bool nullable) {
     var cls = className.split('.');
     var nameSpace = cls.take(cls.length - 1).join('_').toLowerCase();
-    return "$nameSpace.${cls.last}";
+    return "$nameSpace.${cls.last}${nullable ? '?' : ''}";
   }
 
-  static String getTypeName(TypeTemplate forTemplate,
-      TemplateDataType templateDataType, List<TypeTemplate> templates) {
+  static String getTypeName(
+      TypeTemplate forTemplate,
+      TemplateDataType templateDataType,
+      List<TypeTemplate> templates,
+      bool nullable) {
     if (templateDataType.type == DataType.Resource) {
       if (templateDataType.typeGuid == forTemplate.classId)
-        return forTemplate.className.split('.').last;
+        return forTemplate.className.split('.').last + (nullable ? "?" : "");
       else {
         var tmp = templates.firstWhere((x) =>
             x.classId == templateDataType.typeGuid &&
@@ -86,11 +89,11 @@ class TemplateGenerator {
 
         if (tmp == null) return "dynamic"; // something went wrong
 
-        return _translateClassName(tmp.className);
+        return _translateClassName(tmp.className, nullable);
       }
     } else if (templateDataType.type == DataType.ResourceArray) {
       if (templateDataType.typeGuid == forTemplate.classId)
-        return "List<${forTemplate.className.split('.').last}>";
+        return "List<${forTemplate.className.split('.').last + (nullable ? '?' : '')}>";
       else {
         var tmp = templates.firstWhere((x) =>
             x.classId == templateDataType.typeGuid &&
@@ -99,27 +102,27 @@ class TemplateGenerator {
 
         if (tmp == null) return "dynamic"; // something went wrong
 
-        return "List<${_translateClassName(tmp.className)}>";
+        return "List<${_translateClassName(tmp.className, nullable)}>";
       }
     } else if (templateDataType.type == DataType.Record) {
       if (templateDataType.typeGuid == forTemplate.classId)
-        return forTemplate.className.split('.').last;
+        return forTemplate.className.split('.').last + (nullable ? '?' : '');
       else {
         var tmp = templates.firstWhere((x) =>
             x.classId == templateDataType.typeGuid &&
             x.type == TemplateType.Record);
         if (tmp == null) return "dynamic"; // something went wrong
-        return _translateClassName(tmp.className);
+        return _translateClassName(tmp.className, nullable);
       }
     } else if (templateDataType.type == DataType.RecordArray) {
       if (templateDataType.typeGuid == forTemplate.classId)
-        return "List<${forTemplate.className.split('.').last}>";
+        return "List<${forTemplate.className.split('.').last + (nullable ? '?' : '')}?>";
       else {
         var tmp = templates.firstWhere((x) =>
             x.classId == templateDataType.typeGuid &&
             x.type == TemplateType.Record);
         if (tmp == null) return "dynamic"; // something went wrong
-        return "List<${_translateClassName(tmp.className)}>";
+        return "List<${_translateClassName(tmp.className, nullable)}>";
       }
     }
 
@@ -130,13 +133,13 @@ class TemplateGenerator {
         case DataType.BoolArray:
           return "List<bool>";
         case DataType.Char:
-          return "String";
+          return "String" + (nullable ? "?" : "");
         case DataType.CharArray:
-          return "List<String>";
+          return "List<String${nullable ? '?' : ''}>";
         case DataType.DateTime:
           return "DateTime";
         case DataType.DateTimeArray:
-          return "List<DateTime>";
+          return "List<DateTime${nullable ? '?' : ''}>";
         case DataType.Decimal:
           return "double";
         case DataType.DecimalArray:
@@ -168,11 +171,11 @@ class TemplateGenerator {
         case DataType.String:
           return "String";
         case DataType.StringArray:
-          return "List<String>";
+          return "List<String${nullable ? '?' : ''}>";
         case DataType.Structure:
-          return "Structure";
+          return "Structure" + (nullable ? "?" : "");
         case DataType.StructureArray:
-          return "List<Structure>";
+          return "List<Structure${(nullable ? '?' : '')}>";
         case DataType.UInt16:
           return "int";
         case DataType.UInt16Array:
@@ -206,24 +209,24 @@ class TemplateGenerator {
   }
 
   static Future<String> getTemplate(String url,
-      [String dir = null,
-      String username = null,
-      String password = null]) async {
+      [String? dir = null,
+      String? username = null,
+      String? password = null]) async {
     try {
       if (!_urlRegex.hasMatch(url)) throw Exception("Invalid IIP URL");
 
       var path = _urlRegex.allMatches(url).first;
       var con = await Warehouse.get<DistributedConnection>(
-          path[1] + "://" + path[2],
+          (path[1] as String) + "://" + (path[2] as String),
           !isNullOrEmpty(username) && !isNullOrEmpty(password)
               ? {username: username, password: password}
               : null);
 
       if (con == null) throw Exception("Can't connect to server");
 
-      if (isNullOrEmpty(dir)) dir = path[2].replaceAll(":", "_");
+      if (isNullOrEmpty(dir)) dir = (path[2] as String).replaceAll(":", "_");
 
-      var templates = await con.getLinkTemplates(path[3]);
+      var templates = await con.getLinkTemplates(path[3] as String);
 
       // no longer needed
       Warehouse.remove(con);
@@ -234,7 +237,7 @@ class TemplateGenerator {
 
       //Map<String, String> namesMap = Map<String, String>();
 
-      var makeImports = (TypeTemplate skipTemplate) {
+      var makeImports = (TypeTemplate? skipTemplate) {
         var imports = StringBuffer();
         imports.writeln("import 'dart:async';");
         imports.writeln("import 'package:esiur/esiur.dart';");
@@ -270,12 +273,12 @@ class TemplateGenerator {
 
       var defineCreators = templates.map((tmp) {
         // creator
-        var className = _translateClassName(tmp.className);
-        return "Warehouse.defineCreator(${className}, () => ${className}(), () => <${className}>[]);";
+        var className = _translateClassName(tmp.className, false);
+        return "Warehouse.defineCreator(${className}, () => ${className}(), () => <${className}?>[]);";
       }).join("\r\n");
 
       var putTemplates = templates.map((tmp) {
-        var className = _translateClassName(tmp.className);
+        var className = _translateClassName(tmp.className, false);
         return "Warehouse.putTemplate(TypeTemplate.fromType(${className}));";
       }).join("\r\n");
 
@@ -291,7 +294,7 @@ class TemplateGenerator {
     }
   }
 
-  static String _escape(String str) {
+  static String _escape(String? str) {
     if (str == null)
       return "null";
     else
@@ -316,10 +319,11 @@ class TemplateGenerator {
     rt.writeln("}");
 
     template.functions.forEach((f) {
-      var rtTypeName = getTypeName(template, f.returnType, templates);
+      var rtTypeName = getTypeName(template, f.returnType, templates, true);
       rt.write("AsyncReply<$rtTypeName> ${f.name}(");
       rt.write(f.arguments
-          .map((x) => getTypeName(template, x.type, templates) + " " + x.name)
+          .map((x) =>
+              getTypeName(template, x.type, templates, true) + " " + x.name)
           .join(","));
 
       rt.writeln(") {");
@@ -333,14 +337,14 @@ class TemplateGenerator {
     });
 
     template.properties.forEach((p) {
-      var ptTypeName = getTypeName(template, p.valueType, templates);
+      var ptTypeName = getTypeName(template, p.valueType, templates, true);
       rt.writeln("${ptTypeName} get ${p.name} { return get(${p.index}); }");
       rt.writeln(
           "set ${p.name}(${ptTypeName} value) { set(${p.index}, value); }");
     });
 
     template.events.forEach((e) {
-      var etTypeName = getTypeName(template, e.argumentType, templates);
+      var etTypeName = getTypeName(template, e.argumentType, templates, true);
 
       rt.writeln(
           "final _${e.name}Controller = StreamController<$etTypeName>();");
@@ -353,22 +357,22 @@ class TemplateGenerator {
     var descProps = template.properties.map((p) {
       var isArray = p.valueType.type & 0x80 == 0x80;
       var ptType = p.valueType.type & 0x7F;
-      var ptTypeName = getTypeName(
-          template, TemplateDataType(ptType, p.valueType.typeGuid), templates);
+      var ptTypeName = getTypeName(template,
+          TemplateDataType(ptType, p.valueType.typeGuid), templates, false);
       return "Prop('${p.name}', ${ptTypeName}, ${isArray}, ${_escape(p.readExpansion)}, ${_escape(p.writeExpansion)})";
     }).join(', ');
 
     var descFuncs = template.functions.map((f) {
       var isArray = f.returnType.type & 0x80 == 0x80;
       var ftType = f.returnType.type & 0x7F;
-      var ftTypeName = getTypeName(
-          template, TemplateDataType(ftType, f.returnType.typeGuid), templates);
+      var ftTypeName = getTypeName(template,
+          TemplateDataType(ftType, f.returnType.typeGuid), templates, false);
 
       var args = f.arguments.map((a) {
         var isArray = a.type.type & 0x80 == 0x80;
         var atType = a.type.type & 0x7F;
-        var atTypeName = getTypeName(
-            template, TemplateDataType(atType, a.type.typeGuid), templates);
+        var atTypeName = getTypeName(template,
+            TemplateDataType(atType, a.type.typeGuid), templates, false);
         return "Arg('${a.name}', ${atTypeName}, ${isArray})";
       }).join(', ');
 
@@ -379,7 +383,7 @@ class TemplateGenerator {
       var isArray = e.argumentType.type & 0x80 == 0x80;
       var etType = e.argumentType.type & 0x7F;
       var etTypeName = getTypeName(template,
-          TemplateDataType(etType, e.argumentType.typeGuid), templates);
+          TemplateDataType(etType, e.argumentType.typeGuid), templates, false);
       return "Evt('${e.name}', ${etTypeName}, ${isArray}, ${e.listenable}, ${_escape(e.expansion)})";
     }).join(', ');
 

lib/src/Resource/FactoryEntry.dart

@@ -1,7 +1,7 @@
 class FactoryEntry {
   final Type type;
-  final Function() instanceCreator;
-  final Function() arrayCreator;
+  final Function instanceCreator;
+  final Function arrayCreator;
 
   FactoryEntry(this.type, this.instanceCreator, this.arrayCreator);
 }

lib/src/Resource/IResource.dart

@@ -33,7 +33,7 @@ import 'Instance.dart';
 abstract class IResource extends IDestructible {
   AsyncReply<bool> trigger(ResourceTrigger trigger);
 
-  Instance instance;
+  Instance? instance;
 
   invoke(String name, List arguments);
   setProperty(String name, value);

lib/src/Resource/IStore.dart

@@ -31,15 +31,17 @@ import '../Data/PropertyValue.dart';
 // old
 // abstract class IStore extends IResource
 // new
-abstract class IStore implements IResource
-{
-    AsyncReply<IResource> get(String path);
-    AsyncReply<IResource> retrieve(int iid);
+abstract class IStore implements IResource {
+  AsyncReply<IResource?> get(String path);
+  AsyncReply<IResource?> retrieve(int iid);
   AsyncReply<bool> put(IResource resource);
-    String link(IResource resource);
-    bool record(IResource resource, String propertyName, dynamic value, int age, DateTime dateTime);
-    bool modify(IResource resource, String propertyName, dynamic value, int age, DateTime dateTime);
+  String? link(IResource resource);
+  bool record(IResource resource, String propertyName, dynamic value, int age,
+      DateTime dateTime);
+  bool modify(IResource resource, String propertyName, dynamic value, int age,
+      DateTime dateTime);
   bool remove(IResource resource);
 
-    AsyncReply<KeyList<PropertyTemplate, List<PropertyValue>>> getRecord(IResource resource, DateTime fromDate, DateTime toDate);
+  AsyncReply<KeyList<PropertyTemplate, List<PropertyValue>>?> getRecord(
+      IResource resource, DateTime fromDate, DateTime toDate);
 }

lib/src/Resource/Instance.dart

@@ -21,73 +21,61 @@ import './Template/MemberTemplate.dart';
 import '../Data/PropertyValue.dart';
 import 'Warehouse.dart';
 
-class Instance extends IEventHandler
-{
+class Instance extends IEventHandler {
   String _name;
 
-    AutoList<IResource, Instance> _children;
+  late AutoList<IResource, Instance> _children;
   IResource _resource;
-    IStore _store;
-    AutoList<IResource, Instance> _parents;
+  IStore? _store;
+  late AutoList<IResource, Instance> _parents;
   //bool inherit;
-    TypeTemplate _template;
+  late TypeTemplate _template;
 
-    AutoList<IPermissionsManager, Instance> _managers;
+  late AutoList<IPermissionsManager, Instance> _managers;
 
+  late KeyList<String, dynamic> _attributes;
 
-    KeyList<String, dynamic> _attributes;
-
-    List<int> _ages = new List<int>();
-    List<DateTime> _modificationDates = new List<DateTime>();
+  List<int> _ages = <int>[];
+  List<DateTime> _modificationDates = <DateTime>[];
   int _instanceAge;
-    DateTime _instanceModificationDate;
+  DateTime? _instanceModificationDate;
 
   int _id;
 
-
   /// <summary>
   /// Instance attributes are custom properties associated with the instance, a place to store information by IStore.
   /// </summary>
   KeyList<String, dynamic> get attributes => _attributes;
 
   @override
-    String toString() => _name + " (" + link + ")";
+  String toString() => _name + " (" + (link ?? '') + ")";
 
-
-    bool removeAttributes([List<String> attributes = null])
-    {
+  bool removeAttributes([List<String>? attributes = null]) {
     if (attributes == null)
       this._attributes.clear();
-        else
-        {
-            for (var attr in attributes)
-                this.attributes.remove(attr);
+    else {
+      for (var attr in attributes) this.attributes.remove(attr);
     }
 
     return true;
   }
 
-    Structure getAttributes([List<String> attributes = null])
-    {
+  Structure getAttributes([List<String>? attributes = null]) {
     var st = new Structure();
 
-        if (attributes == null)
-        {
+    if (attributes == null) {
       var clone = this.attributes.keys.toList();
       clone.add("managers");
       attributes = clone.toList();
     }
 
-        for(var attr in attributes)
-        {
+    for (var attr in attributes) {
       if (attr == "name")
         st["name"] = _name;
-            else if (attr == "managers")
-            {
-                var mngrs = new List<Structure>();
+      else if (attr == "managers") {
+        var mngrs = <Structure>[];
 
-                for (var i = 0; i < _managers.length; i++)
-                {
+        for (var i = 0; i < _managers.length; i++) {
           var mst = new Structure();
           mst["type"] = _managers[i].runtimeType;
           mst["settings"] = _managers[i].settings;
@@ -96,43 +84,29 @@ class Instance extends IEventHandler
         }
 
         st["managers"] = mngrs;
-            }
-            else if (attr == "parents")
-            {
+      } else if (attr == "parents") {
         st["parents"] = _parents.toList();
-            }
-            else if (attr == "children")
-            {
+      } else if (attr == "children") {
         st["children"] = _children.toList();
-            }
-            else if (attr == "childrenCount")
-            {
+      } else if (attr == "childrenCount") {
         st["childrenCount"] = _children.count;
-            }
-            else if (attr == "type")
-            {
+      } else if (attr == "type") {
         st["type"] = resource.runtimeType;
-            }
-            else
+      } else
         st[attr] = _attributes[attr];
     }
 
     return st;
   }
 
-    bool setAttributes(Structure attributes, [bool clearAttributes = false])
-    {            
-        try
-        {
-
-            if (clearAttributes)
-                _attributes.clear();
+  bool setAttributes(Structure attributes, [bool clearAttributes = false]) {
+    try {
+      if (clearAttributes) _attributes.clear();
 
       for (var attrKey in attributes.keys)
         if (attrKey == "name")
-                    _name = attributes[attrKey];
-                else if (attrKey == "managers")
-                {
+          _name = attributes[attrKey] as String;
+        else if (attrKey == "managers") {
           _managers.clear();
 
           var mngrs = attributes[attrKey] as List;
@@ -153,15 +127,10 @@ class Instance extends IEventHandler
                             return false;
                     }
                     */
-                }
-                else
-                {
+        } else {
           _attributes[attrKey] = attributes[attrKey];
         }
-            
-        }
-        catch(ex)
-        {
+    } catch (ex) {
       return false;
     }
 
@@ -197,8 +166,7 @@ class Instance extends IEventHandler
   /// </summary>
   /// <param name="index">Zero-based property index.</param>
   /// <returns>Age.</returns>
-    int getAge(int index)
-    {
+  int getAge(int index) {
     if (index < _ages.length)
       return _ages[index];
     else
@@ -210,13 +178,10 @@ class Instance extends IEventHandler
   /// </summary>
   /// <param name="index">Zero-based property index.</param>
   /// <param name="value">Age.</param>
-    void setAge(int index, int value)
-    {
-        if (index < _ages.length)
-        {
+  void setAge(int index, int value) {
+    if (index < _ages.length) {
       _ages[index] = value;
-            if (value > _instanceAge)
-                _instanceAge = value;
+      if (value > _instanceAge) _instanceAge = value;
     }
   }
 
@@ -225,12 +190,12 @@ class Instance extends IEventHandler
   /// </summary>
   /// <param name="index">Zero-based property index.</param>
   /// <param name="value">Modification date.</param>
-    void setModificationDate(int index, DateTime value)
-    {
-        if (index < _modificationDates.length)
-        {
+  void setModificationDate(int index, DateTime value) {
+    if (index < _modificationDates.length) {
       _modificationDates[index] = value;
-            if (_instanceModificationDate == null || value.millisecondsSinceEpoch > _instanceModificationDate.millisecondsSinceEpoch)
+      if (_instanceModificationDate == null ||
+          value.millisecondsSinceEpoch >
+              (_instanceModificationDate as DateTime).millisecondsSinceEpoch)
         _instanceModificationDate = value;
     }
   }
@@ -240,15 +205,13 @@ class Instance extends IEventHandler
   /// </summary>
   /// <param name="index">Zero-based property index</param>
   /// <returns>Modification date.</returns>
-    DateTime getModificationDate(int index)
-    {
+  DateTime getModificationDate(int index) {
     if (index < _modificationDates.length)
       return _modificationDates[index];
     else
       return new DateTime(0);
   }
 
-    
   /// <summary>
   /// Load property value (used by stores)
   /// </summary>
@@ -256,8 +219,8 @@ class Instance extends IEventHandler
   /// <param name="age">Property age</param>
   /// <param name="value">Property value</param>
   /// <returns></returns>
-    bool loadProperty(String name, int age, DateTime modificationDate, dynamic value)
-    {
+  bool loadProperty(
+      String name, int age, DateTime modificationDate, dynamic value) {
     /*
         var pt = _template.getPropertyTemplate(name);
 
@@ -282,7 +245,6 @@ class Instance extends IEventHandler
 
       */
     return true;
-
   }
 
   /// <summary>
@@ -290,12 +252,12 @@ class Instance extends IEventHandler
   /// </summary>
   int get age => _instanceAge;
   // this must be internal
-    set age (value) => _instanceAge = value;
+  set age(value) => _instanceAge = value;
 
   /// <summary>
   /// Last modification date.
   /// </summary>
-    DateTime get modificationDate => _instanceModificationDate;
+  DateTime? get modificationDate => _instanceModificationDate;
 
   /// <summary>
   /// Instance Id.
@@ -307,13 +269,10 @@ class Instance extends IEventHandler
   /// </summary>
   /// <param name="properties"></param>
   /// <returns></returns>
-    bool deserialize(List<PropertyValue> properties)
-    {
-        for (var i = 0; i < properties.length; i++)
-        {
+  bool deserialize(List<PropertyValue> properties) {
+    for (var i = 0; i < properties.length; i++) {
       var pt = _template.getPropertyTemplateByIndex(i);
-            if (pt != null)
-            {
+      if (pt != null) {
         var pv = properties[i];
         loadProperty(pt.name, pv.age, pv.date, pv.value);
       }
@@ -326,12 +285,10 @@ class Instance extends IEventHandler
   /// Export all properties with ResourceProperty attributed as bytes array.
   /// </summary>
   /// <returns></returns>
-    List<PropertyValue> serialize()
-    {
-        List<PropertyValue> props = new List<PropertyValue>();
+  List<PropertyValue> serialize() {
+    List<PropertyValue> props = <PropertyValue>[];
 
-        for (var pt in _template.properties)
-        {
+    for (var pt in _template.properties) {
       //   var rt = pt.info.getValue(resource, null);
       // props.add(new PropertyValue(rt, _ages[pt.index], _modificationDates[pt.index]));
     }
@@ -409,27 +366,21 @@ class Instance extends IEventHandler
   /// If True, the instance can be stored to disk.
   /// </summary>
   /// <returns></returns>
-    bool isStorable()
-    {
+  bool isStorable() {
     return false;
   }
 
-
-    void emitModification(PropertyTemplate pt, dynamic value)
-    {
+  void emitModification(PropertyTemplate pt, dynamic value) {
     _instanceAge++;
     var now = DateTime.now().toUtc();
 
     _ages[pt.index] = _instanceAge;
     _modificationDates[pt.index] = now;
 
-        if (pt.storage == StorageMode.NonVolatile)
-        {
-            _store.modify(_resource, pt.name, value, _ages[pt.index], now);
-        }
-        else if (pt.storage == StorageMode.Recordable)
-        { 
-            _store.record(_resource, pt.name, value, _ages[pt.index], now);
+    if (pt.storage == StorageMode.NonVolatile) {
+      _store?.modify(_resource, pt.name, value, _ages[pt.index], now);
+    } else if (pt.storage == StorageMode.Recordable) {
+      _store?.record(_resource, pt.name, value, _ages[pt.index], now);
     }
 
     emitArgs("resourceModified", [_resource, pt.name, value]);
@@ -443,19 +394,18 @@ class Instance extends IEventHandler
   /// <param name="propertyName"></param>
   /// <param name="newValue"></param>
   /// <param name="oldValue"></param>
-    modified(String propertyName)
-    {
+  modified(String propertyName) {
     var valueObject = new ValueObject();
-        if (getPropertyValue(propertyName, valueObject))
-        {
+    if (getPropertyValue(propertyName, valueObject)) {
       var pt = _template.getPropertyTemplateByName(propertyName);
-            emitModification(pt, valueObject.value);
+      if (pt != null) emitModification(pt, valueObject.value);
     }
   }
 
-    emitResourceEvent(issuer, List<Session> receivers, String name, dynamic args)
-    {
-        emitArgs("resourceEventOccurred", [_resource, issuer, receivers, name, args]);
+  emitResourceEvent(
+      issuer, List<Session>? receivers, String name, dynamic args) {
+    emitArgs(
+        "resourceEventOccurred", [_resource, issuer, receivers, name, args]);
   }
 
   /// <summary>
@@ -464,8 +414,7 @@ class Instance extends IEventHandler
   /// <param name="name">Property name</param>
   /// <param name="value">Output value</param>
   /// <returns>True, if the resource has the property.</returns>
-    bool getPropertyValue(String name, ValueObject valueObject)
-    {
+  bool getPropertyValue(String name, ValueObject valueObject) {
     var pt = _template.getPropertyTemplateByName(name);
 
     /*
@@ -480,7 +429,6 @@ class Instance extends IEventHandler
     return false;
   }
 
-
   /*
     public bool Inherit
     {
@@ -492,11 +440,10 @@ class Instance extends IEventHandler
   /// </summary>
   AutoList<IResource, Instance> get parents => _parents;
 
-
   /// <summary>
   /// Store responsible for creating and keeping the resource.
   /// </summary>
-    IStore get store => _store;
+  IStore? get store => _store;
 
   /// <summary>
   /// List of children.
@@ -506,29 +453,27 @@ class Instance extends IEventHandler
   /// <summary>
   /// The unique and permanent link to the resource.
   /// </summary>
-    String get link
-    {
+  String? get link {
     if (_store != null)
-            return _store.link(_resource);
-        else
-        {
-            var l = new List<String>();
+      return _store?.link(_resource);
+    else {
+      var l = <String>[];
 
       var p = _resource;
 
-            while (true)
-            {
-                l.insert(0, p.instance.name);
+      while (true) {
+        if (p.instance != null) break;
+        var pi = p.instance as Instance;
 
-                if (p.instance.parents.count == 0)
-                    break;
+        l.insert(0, pi.name);
 
-                p = p.instance.parents.first();
+        if (pi.parents.count == 0) break;
+
+        p = pi.parents.first;
       }
 
       return l.join("/");
     }
-    
   }
 
   /// <summary>
@@ -537,13 +482,11 @@ class Instance extends IEventHandler
   String get name => _name;
   set name(value) => name = value;
 
-
   /// <summary>
   /// Resource managed by this instance.
   /// </summary>
   IResource get resource => _resource;
 
-    
   /// <summary>
   /// Resource template describes the properties, functions and events of the resource.
   /// </summary>
@@ -557,18 +500,15 @@ class Instance extends IEventHandler
   /// <param name="member">Function, property or event to check for permission.</param>
   /// <param name="inquirer">Permission inquirer.</param>
   /// <returns>Ruling.</returns>
-    Ruling applicable(Session session, ActionType action, MemberTemplate member, [dynamic inquirer = null])
-    {
-        
-        for(var i = 0; i < _managers.length; i++)
-        {
-            var r = _managers[i].applicable(this.resource, session, action, member, inquirer);
-            if (r != Ruling.DontCare)
-                return r;
+  Ruling applicable(Session session, ActionType action, MemberTemplate? member,
+      [dynamic inquirer = null]) {
+    for (var i = 0; i < _managers.length; i++) {
+      var r = _managers[i]
+          .applicable(this.resource, session, action, member, inquirer);
+      if (r != Ruling.DontCare) return r;
     }
 
     return Ruling.DontCare;
-
   }
 
   /// <summary>
@@ -583,14 +523,8 @@ class Instance extends IEventHandler
   /// <param name="name">Name of the instance.</param>
   /// <param name="resource">Resource to manage.</param>
   /// <param name="store">Store responsible for the resource.</param>
-    Instance(int id, String name, IResource resource, IStore store, [TypeTemplate customTemplate = null, int age = 0])
-    {
-        _store = store;
-        _resource = resource;
-        _id = id;
-        _name = name;
-        _instanceAge = age;
-
+  Instance(this._id, this._name, this._resource, this._store,
+      [TypeTemplate? customTemplate = null, this._instanceAge = 0]) {
     _attributes = new KeyList<String, dynamic>(this);
     _children = new AutoList<IResource, Instance>(this);
     _parents = new AutoList<IResource, Instance>(this);
@@ -609,10 +543,9 @@ class Instance extends IEventHandler
       _template = Warehouse.getTemplateByType(resource.runtimeType);
 
     // set ages
-        for (int i = 0; i < _template.properties.length; i++)
-        {
+    for (int i = 0; i < _template.properties.length; i++) {
       _ages.add(0);
-            _modificationDates.add(new DateTime(0));//DateTime.MinValue);
+      _modificationDates.add(new DateTime(0)); //DateTime.MinValue);
     }
 
     /*
@@ -652,31 +585,31 @@ class Instance extends IEventHandler
         */
   }
 
-    void children_OnRemoved(Instance parent, IResource value)
-    {
-        value.instance.parents.remove(_resource);
+  void children_OnRemoved(Instance parent, IResource value) {
+    value.instance?.parents.remove(_resource);
   }
 
-    void children_OnAdd(Instance parent, IResource value)
-    {
-        if (!value.instance.parents.contains(_resource))
-            value.instance.parents.add(_resource);
+  void children_OnAdd(Instance parent, IResource value) {
+    if (value.instance != null) {
+      var ins = value.instance as Instance;
+      if (ins.parents.contains(_resource))
+        value.instance?.parents.add(_resource);
+    }
   }
 
-    void parents_OnRemoved(Instance parent, IResource value)
-    {
-        value.instance.children.remove(_resource);
+  void parents_OnRemoved(Instance parent, IResource value) {
+    value.instance?.children.remove(_resource);
   }
 
-    void parents_OnAdd(Instance parent, IResource value)
-    {
-        if (!value.instance.children.contains(_resource))
-            value.instance.children.add(_resource);
+  void parents_OnAdd(Instance parent, IResource value) {
+    if (value.instance != null) {
+      var ins = value.instance as Instance;
+      if (!ins.children.contains(_resource))
+        value.instance?.children.add(_resource);
+    }
   }
 
-
-    void resource_OnDestroy(sender)
-    {
+  void resource_OnDestroy(sender) {
     emitArgs("resourceDestroyed", [sender]);
   }
 }

lib/src/Resource/Template/ArgumentTemplate.dart

@@ -3,32 +3,30 @@ import '../../Data/BinaryList.dart';
 import "../../Data/ParseResult.dart";
 import './TemplateDataType.dart';
 
-class ArgumentTemplate
-{
+class ArgumentTemplate {
   String name;
 
   TemplateDataType type;
 
-      static ParseResult<ArgumentTemplate> parse(DC data, int offset)
-      {
+  static ParseResult<ArgumentTemplate> parse(DC data, int offset) {
     var cs = data[offset++];
     var name = data.getString(offset, cs);
     offset += cs;
     var tdr = TemplateDataType.parse(data, offset);
 
-          return ParseResult<ArgumentTemplate>(cs + 1 + tdr.size, ArgumentTemplate(name, tdr.value));
+    return ParseResult<ArgumentTemplate>(
+        cs + 1 + tdr.size, ArgumentTemplate(name, tdr.value));
   }
 
   ArgumentTemplate(this.name, this.type);
 
-      DC compose()
-      {
+  DC compose() {
     var name = DC.stringToBytes(this.name);
 
-          return new BinaryList()
-                  .addUint8(name.length)
-                  .addDC(name)
-                  .addDC(type.compose())
+    return (BinaryList()
+          ..addUint8(name.length)
+          ..addDC(name)
+          ..addDC(type.compose()))
         .toDC();
   }
-  }
+}

lib/src/Resource/Template/EventTemplate.dart

@@ -6,7 +6,7 @@ import 'MemberType.dart';
 import 'TemplateDataType.dart';
 
 class EventTemplate extends MemberTemplate {
-  String expansion;
+  String? expansion;
   bool listenable;
   TemplateDataType argumentType;
 
@@ -14,21 +14,21 @@ class EventTemplate extends MemberTemplate {
     var name = super.compose();
 
     if (expansion != null) {
-      var exp = DC.stringToBytes(expansion);
-      return new BinaryList()
-          .addUint8(listenable ? 0x58 : 0x50)
-          .addUint8(name.length)
-          .addDC(name)
-          .addDC(argumentType.compose())
-          .addInt32(exp.length)
-          .addDC(exp)
+      var exp = DC.stringToBytes(expansion as String);
+      return (BinaryList()
+            ..addUint8(listenable ? 0x58 : 0x50)
+            ..addUint8(name.length)
+            ..addDC(name)
+            ..addDC(argumentType.compose())
+            ..addInt32(exp.length)
+            ..addDC(exp))
           .toDC();
     } else {
-      return new BinaryList()
-          .addUint8(listenable ? 0x48 : 0x40)
-          .addUint8(name.length)
-          .addDC(name)
-          .addDC(argumentType.compose())
+      return (BinaryList()
+            ..addUint8(listenable ? 0x48 : 0x40)
+            ..addUint8(name.length)
+            ..addDC(name)
+            ..addDC(argumentType.compose()))
           .toDC();
     }
   }

lib/src/Resource/Template/FunctionTemplate.dart

@@ -7,8 +7,8 @@ import 'ArgumentTemplate.dart';
 import 'TemplateDataType.dart';
 
 class FunctionTemplate extends MemberTemplate {
-  String expansion;
-  bool isVoid;
+  String? expansion;
+ // bool isVoid;
 
   TemplateDataType returnType;
   List<ArgumentTemplate> arguments;
@@ -18,10 +18,10 @@ class FunctionTemplate extends MemberTemplate {
       var name = super.compose();
             
       var bl = new BinaryList()
-              .addUint8(name.length)
-              .addDC(name)
-              .addDC(returnType.compose())
-              .addUint8(arguments.length);
+              ..addUint8(name.length)
+              ..addDC(name)
+              ..addDC(returnType.compose())
+              ..addUint8(arguments.length);
 
       for (var i = 0; i < arguments.length; i++)
           bl.addDC(arguments[i].compose());
@@ -29,9 +29,9 @@ class FunctionTemplate extends MemberTemplate {
 
       if (expansion != null)
       {
-          var exp = DC.stringToBytes(expansion);
-          bl.addInt32(exp.length)
-          .addDC(exp);
+          var exp = DC.stringToBytes(expansion as String);
+          bl..addInt32(exp.length)
+            ..addDC(exp);
           bl.insertUint8(0, 0x10);
       }
       else
@@ -41,9 +41,9 @@ class FunctionTemplate extends MemberTemplate {
   }
 
   FunctionTemplate(TypeTemplate template, int index, String name,
-      this.arguments, this.returnType, String expansion)
+      this.arguments, this.returnType, this.expansion)
       : super(template, MemberType.Property, index, name) {
-    this.isVoid = isVoid;
-    this.expansion = expansion;
+    
+    
   }
 }

lib/src/Resource/Template/MemberTemplate.dart

@@ -17,12 +17,8 @@ class MemberTemplate
 
     TypeTemplate get template => _template;
 
-    MemberTemplate(TypeTemplate template, MemberType type, int index, String name)
+    MemberTemplate(this._template, this._type, this._index, this._name)
     {
-        this._template = template;
-        this._type = type;
-        this._index = index;
-        this._name = name;
     }
 
     String get fullname => _template.className + "." + _name;

lib/src/Resource/Template/PropertyTemplate.dart

@@ -14,63 +14,59 @@ class PropertyTemplate extends MemberTemplate {
 
   int storage;
 
-  String readExpansion;
+  String? readExpansion;
 
-  String writeExpansion;
+  String? writeExpansion;
 
   DC compose() {
     var name = super.compose();
     var pv = ((permission) << 1) | (storage == StorageMode.Recordable ? 1 : 0);
 
     if (writeExpansion != null && readExpansion != null) {
-      var rexp = DC.stringToBytes(readExpansion);
-      var wexp = DC.stringToBytes(writeExpansion);
-      return new BinaryList()
-          .addUint8(0x38 | pv)
-          .addUint8(name.length)
-          .addDC(name)
-          .addDC(valueType.compose())
-          .addInt32(wexp.length)
-          .addDC(wexp)
-          .addInt32(rexp.length)
-          .addDC(rexp)
+      var rexp = DC.stringToBytes(readExpansion as String);
+      var wexp = DC.stringToBytes(writeExpansion as String);
+      return (BinaryList()
+            ..addUint8(0x38 | pv)
+            ..addUint8(name.length)
+            ..addDC(name)
+            ..addDC(valueType.compose())
+            ..addInt32(wexp.length)
+            ..addDC(wexp)
+            ..addInt32(rexp.length)
+            ..addDC(rexp))
           .toDC();
     } else if (writeExpansion != null) {
-      var wexp = DC.stringToBytes(writeExpansion);
-      return new BinaryList()
-          .addUint8(0x30 | pv)
-          .addUint8(name.length)
-          .addDC(name)
-          .addDC(valueType.compose())
-          .addInt32(wexp.length)
-          .addDC(wexp)
+      var wexp = DC.stringToBytes(writeExpansion as String);
+      return (BinaryList()
+            ..addUint8(0x30 | pv)
+            ..addUint8(name.length)
+            ..addDC(name)
+            ..addDC(valueType.compose())
+            ..addInt32(wexp.length)
+            ..addDC(wexp))
           .toDC();
     } else if (readExpansion != null) {
-      var rexp = DC.stringToBytes(readExpansion);
-      return new BinaryList()
-          .addUint8(0x28 | pv)
-          .addUint8(name.length)
-          .addDC(name)
-          .addDC(valueType.compose())
-          .addInt32(rexp.length)
-          .addDC(rexp)
+      var rexp = DC.stringToBytes(readExpansion as String);
+      return (BinaryList()
+            ..addUint8(0x28 | pv)
+            ..addUint8(name.length)
+            ..addDC(name)
+            ..addDC(valueType.compose())
+            ..addInt32(rexp.length)
+            ..addDC(rexp))
           .toDC();
     } else
-      return new BinaryList()
-          .addUint8(0x20 | pv)
-          .addUint8(name.length)
-          .addDC(name)
-          .addDC(valueType.compose())
+      return (BinaryList()
+            ..addUint8(0x20 | pv)
+            ..addUint8(name.length)
+            ..addDC(name)
+            ..addDC(valueType.compose()))
           .toDC();
   }
 
   PropertyTemplate(TypeTemplate template, int index, String name,
-      TemplateDataType valueType, String read, String write, int storage)
+      this.valueType, this.readExpansion, this.writeExpansion, this.storage)
       : super(template, MemberType.Property, index, name) {
     //this.Recordable = recordable;
-    this.storage = storage;
-    this.readExpansion = read;
-    this.writeExpansion = write;
-    this.valueType = valueType;
   }
 }

lib/src/Resource/Template/TemplateDataType.dart

@@ -16,11 +16,12 @@ import '../../Resource/Warehouse.dart';
 import 'TemplateType.dart';
 
 class TemplateDataType {
-  int type;
-  TypeTemplate get typeTemplate =>
-      typeGuid == null ? null : Warehouse.getTemplateByClassId(typeGuid);
+  late int type;
+  TypeTemplate? get typeTemplate => typeGuid == null
+      ? null
+      : Warehouse.getTemplateByClassId(typeGuid as Guid);
 
-  Guid typeGuid;
+  Guid? typeGuid;
 
 //  @TODO: implement fromType
   TemplateDataType.fromType(type, bool isArray) {
@@ -98,7 +99,10 @@ class TemplateDataType {
         type == DataType.ResourceArray ||
         type == DataType.Record ||
         type == DataType.RecordArray) {
-      return BinaryList().addUint8(type).addDC(typeGuid.value).toDC();
+      return (BinaryList()
+            ..addUint8(type)
+            ..addDC((typeGuid as Guid).value))
+          .toDC();
     } else
       return DC.fromList([type]);
   }

lib/src/Resource/Template/TemplateDescriber.dart

@@ -1,9 +1,9 @@
 import '../../Data/DataType.dart';
 
 class TemplateDescriber {
-  final List<Prop> properties;
-  final List<Evt> events;
-  final List<Func> functions;
+  final List<Prop>? properties;
+  final List<Evt>? events;
+  final List<Func>? functions;
   final String nameSpace;
   final int version;
 
@@ -47,8 +47,8 @@ class Prop {
   final String name;
   final Type type;
   final bool isArray;
-  final String readAnnotation;
-  final String writeAnnotation;
+  final String? readAnnotation;
+  final String? writeAnnotation;
   Prop(this.name, this.type, this.isArray,
       [this.readAnnotation = null, this.writeAnnotation = null]);
 }
@@ -58,7 +58,7 @@ class Evt {
   final bool listenable;
   final Type type;
   final bool isArray;
-  final String annotation;
+  final String? annotation;
 
   Evt(this.name, this.type, this.isArray,
       [this.listenable = false, this.annotation]);
@@ -69,7 +69,7 @@ class Func {
   final Type returnType;
   final List<Arg> argsType;
   final bool isArray;
-  final String annotation;
+  final String? annotation;
 
   Func(this.name, this.returnType, this.isArray, this.argsType,
       [this.annotation = null]);

lib/src/Resource/Template/TypeTemplate.dart

@@ -22,26 +22,26 @@ import 'TemplateDataType.dart';
 import 'TemplateType.dart';
 
 class TypeTemplate {
-  Guid _classId;
-  String _className;
+  late Guid _classId;
+  late String _className;
   List<MemberTemplate> _members = [];
   List<FunctionTemplate> _functions = [];
   List<EventTemplate> _events = [];
   List<PropertyTemplate> _properties = [];
-  int _version;
+  late int _version;
   //bool isReady;
 
-  TemplateType _templateType;
+  late TemplateType _templateType;
 
-  DC _content;
+  late DC _content;
 
   DC get content => _content;
 
   TemplateType get type => _templateType;
 
-  Type _definedType;
+  Type? _definedType;
 
-  Type get definedType => _definedType;
+  Type? get definedType => _definedType;
 /*
     MemberTemplate getMemberTemplate(MemberInfo member)
     {
@@ -59,32 +59,32 @@ class TypeTemplate {
 //@TODO: implement
   static List<TypeTemplate> getDependencies(TypeTemplate template) => [];
 
-  EventTemplate getEventTemplateByName(String eventName) {
+  EventTemplate? getEventTemplateByName(String eventName) {
     for (var i in _events) if (i.name == eventName) return i;
     return null;
   }
 
-  EventTemplate getEventTemplateByIndex(int index) {
+  EventTemplate? getEventTemplateByIndex(int index) {
     for (var i in _events) if (i.index == index) return i;
     return null;
   }
 
-  FunctionTemplate getFunctionTemplateByName(String functionName) {
+  FunctionTemplate? getFunctionTemplateByName(String functionName) {
     for (var i in _functions) if (i.name == functionName) return i;
     return null;
   }
 
-  FunctionTemplate getFunctionTemplateByIndex(int index) {
+  FunctionTemplate? getFunctionTemplateByIndex(int index) {
     for (var i in _functions) if (i.index == index) return i;
     return null;
   }
 
-  PropertyTemplate getPropertyTemplateByIndex(int index) {
+  PropertyTemplate? getPropertyTemplateByIndex(int index) {
     for (var i in _properties) if (i.index == index) return i;
     return null;
   }
 
-  PropertyTemplate getPropertyTemplateByName(String propertyName) {
+  PropertyTemplate? getPropertyTemplateByName(String propertyName) {
     for (var i in _properties) if (i.name == propertyName) return i;
     return null;
   }
@@ -143,9 +143,11 @@ class TypeTemplate {
     if (addToWarehouse) Warehouse.putTemplate(this);
     // _templates.add(template.classId, template);
 
-    if (describer.properties != null)
-      for (var i = 0; i < describer.properties.length; i++) {
-        var pi = describer.properties[i];
+    if (describer.properties != null) {
+      var props = describer.properties as List<Prop>;
+
+      for (var i = 0; i < props.length; i++) {
+        var pi = props[i];
         var pt = PropertyTemplate(
             this,
             i,
@@ -156,10 +158,13 @@ class TypeTemplate {
             0);
         properties.add(pt);
       }
+    }
 
-    if (describer.functions != null)
-      for (var i = 0; i < describer.functions.length; i++) {
-        var fi = describer.functions[i];
+    if (describer.functions != null) {
+      var funcs = describer.functions as List<Func>;
+
+      for (var i = 0; i < funcs.length; i++) {
+        var fi = funcs[i];
 
         List<ArgumentTemplate> args = fi.argsType
             .map((arg) => ArgumentTemplate(
@@ -176,10 +181,12 @@ class TypeTemplate {
 
         functions.add(ft);
       }
+    }
 
-    if (describer.events != null)
-      for (var i = 0; i < describer.events.length; i++) {
-        var ei = describer.events[i];
+    if (describer.events != null) {
+      var evts = describer.events as List<Evt>;
+      for (var i = 0; i < evts.length; i++) {
+        var ei = evts[i];
 
         var et = new EventTemplate(
             this,
@@ -191,6 +198,7 @@ class TypeTemplate {
 
         events.add(et);
       }
+    }
 
     // append signals
     events.forEach(_members.add);
@@ -200,14 +208,13 @@ class TypeTemplate {
     properties.forEach(_members.add);
 
     // bake it binarily
-    var b = new BinaryList();
-    b
-        .addUint8(_templateType.index)
-        .addGuid(classId)
-        .addUint8(className.length)
-        .addString(className)
-        .addInt32(_version)
-        .addUint16(_members.length);
+    var b = BinaryList()
+      ..addUint8(_templateType.index)
+      ..addGuid(classId)
+      ..addUint8(className.length)
+      ..addString(className)
+      ..addInt32(_version)
+      ..addUint16(_members.length);
 
     functions.forEach((ft) => b.addDC(ft.compose()));
     properties.forEach((pt) => b.addDC(pt.compose()));
@@ -429,7 +436,7 @@ class TypeTemplate {
 
 */
 
-  TypeTemplate.parse(DC data, [int offset = 0, int contentLength]) {
+  TypeTemplate.parse(DC data, [int offset = 0, int? contentLength]) {
     // cool Dart feature
     contentLength ??= data.length;
 
@@ -464,7 +471,7 @@ class TypeTemplate {
 
       if (type == 0) // function
       {
-        String expansion = null;
+        String? expansion = null;
         var hasExpansion = ((data[offset++] & 0x10) == 0x10);
 
         var name = data.getString(offset + 1, data[offset]);
@@ -497,7 +504,7 @@ class TypeTemplate {
         _functions.add(ft);
       } else if (type == 1) // property
       {
-        String readExpansion = null, writeExpansion = null;
+        String? readExpansion = null, writeExpansion = null;
 
         var hasReadExpansion = ((data[offset] & 0x8) == 0x8);
         var hasWriteExpansion = ((data[offset] & 0x10) == 0x10);
@@ -539,7 +546,7 @@ class TypeTemplate {
         _properties.add(pt);
       } else if (type == 2) // Event
       {
-        String expansion = null;
+        String? expansion = null;
         var hasExpansion = ((data[offset] & 0x10) == 0x10);
         var listenable = ((data[offset++] & 0x8) == 0x8);
 

lib/src/Resource/Warehouse.dart

@@ -22,6 +22,10 @@ SOFTWARE.
 
 */
 
+import '../Core/AsyncException.dart';
+import '../Core/ErrorType.dart';
+import '../Core/ExceptionCode.dart';
+
 import '../Data/AutoList.dart';
 import 'FactoryEntry.dart';
 import 'Template/TemplateType.dart';
@@ -41,8 +45,7 @@ import '../Net/IIP/DistributedConnection.dart';
 
 // Centeral Resource Issuer
 class Warehouse {
-  static AutoList<IResource, Instance> _stores =
-      new AutoList<IResource, Instance>(null);
+  static AutoList<IStore, Instance> _stores = AutoList<IStore, Instance>();
   static Map<int, IResource> _resources = new Map<int, IResource>();
   static int resourceCounter = 0;
 
@@ -74,8 +77,8 @@ class Warehouse {
   /// </summary>
   /// <param name="name">Store instance name</param>
   /// <returns></returns>
-  static IStore getStore(String name) {
-    for (var s in _stores) if (s.instance.name == name) return s;
+  static IStore? getStore(String name) {
+    for (var s in _stores) if (s.instance?.name == name) return s;
     return null;
   }
 
@@ -84,11 +87,11 @@ class Warehouse {
   /// </summary>
   /// <param name="id">Instance Id</param>
   /// <returns></returns>
-  static AsyncReply<IResource> getById(int id) {
+  static AsyncReply<IResource?> getById(int id) {
     if (_resources.containsKey(id))
-      return new AsyncReply<IResource>.ready(_resources[id]);
+      return new AsyncReply<IResource?>.ready(_resources[id]);
     else
-      return new AsyncReply<IResource>.ready(null);
+      return new AsyncReply<IResource?>.ready(null);
   }
 
   /// <summary>
@@ -106,20 +109,21 @@ class Warehouse {
     var rt = new AsyncReply<bool>();
     bag.then((x) {
       for (var b in x)
-        if (!b) {
+        if (b == null || b == false) {
           rt.trigger(false);
           return;
         }
 
       var rBag = new AsyncBag<bool>();
       for (var rk in _resources.keys)
-        rBag.add(_resources[rk].trigger(ResourceTrigger.SystemInitialized));
+        rBag.add((_resources[rk] as IResource)
+            .trigger(ResourceTrigger.SystemInitialized));
 
       rBag.seal();
 
       rBag.then((y) {
         for (var b in y)
-          if (!b) {
+          if (b == null || b == false) {
             rt.trigger(false);
             return;
           }
@@ -158,7 +162,7 @@ class Warehouse {
     var rt = new AsyncReply<bool>();
     bag.then((x) {
       for (var b in x)
-        if (!b) {
+        if (b == null || b == false) {
           rt.trigger(false);
           return;
         }
@@ -178,19 +182,21 @@ class Warehouse {
         for (var child in resources) rt.add(child);
       else
         for (var child in resources)
-          if (child.instance.name == path[index]) rt.add(child);
+          if (child.instance?.name == path[index]) rt.add(child);
     } else
       for (var child in resources)
-        if (child.instance.name == path[index])
-          rt.addAll(qureyIn(path, index + 1, child.instance.children));
+        if (child.instance?.name == path[index])
+          rt.addAll(qureyIn(path, index + 1,
+              child.instance?.children as AutoList<IResource, Instance>));
 
     return rt;
   }
 
-  static AsyncReply<List<IResource>> query(String path) {
+  static AsyncReply<List<IResource>?> query(String? path) {
     if (path == null || path == "") {
-      var roots = _stores.where((s) => s.instance.parents.length == 0).toList();
-      return new AsyncReply<List<IResource>>.ready(roots);
+      var roots =
+          _stores.where((s) => s.instance?.parents.length == 0).toList();
+      return new AsyncReply<List<IResource>?>.ready(roots);
     } else {
       var rt = new AsyncReply<List<IResource>>();
       get(path).then((x) {
@@ -215,35 +221,41 @@ class Warehouse {
   /// </summary>
   /// <param name="path"></param>
   /// <returns>Resource instance.</returns>
-  static AsyncReply<T> get<T extends IResource>(String path,
+  static AsyncReply<T?> get<T extends IResource>(String path,
       [attributes = null,
-      IResource parent = null,
-      IPermissionsManager manager = null]) {
-    var rt = AsyncReply<T>();
+      IResource? parent = null,
+      IPermissionsManager? manager = null]) {
+    var rt = AsyncReply<T?>();
 
     // Should we create a new store ?
     if (_urlRegex.hasMatch(path)) {
       var url = _urlRegex.allMatches(path).first;
 
       if (protocols.containsKey(url[1])) {
-        var handler = protocols[url[1]];
+        var handler =
+            protocols[url[1]] as AsyncReply<IStore> Function(String, dynamic);
 
         var getFromStore = () {
-          handler(url[2], attributes).then<IStore>((store) {
-            if (url[3].length > 0 && url[3] != "")
-              store.get(url[3]).then<dynamic>((r) {
-                rt.trigger(r);
-              }).error((e) => rt.triggerError(e));
+          handler(url[2] as String, attributes)
+            ..then((store) {
+              if ((url[3] as String).length > 0 && url[3] != "")
+                store.get(url[3] as String)
+                  ..then((r) {
+                    rt.trigger(r as T);
+                  })
+                  ..error((e) => rt.triggerError(e));
               else
                 rt.trigger(store as T);
-          }).error((e) {
+            })
+            ..error((e) {
               rt.triggerError(e);
               //Warehouse.remove(store);
             });
         };
 
         if (!_warehouseIsOpen)
-          open().then((v) {
+          open()
+            ..then((v) {
               if (v)
                 getFromStore();
               else
@@ -258,7 +270,7 @@ class Warehouse {
 
     query(path).then((rs) {
       if (rs != null && rs.length > 0)
-        rt.trigger(rs[0]);
+        rt.trigger(rs[0] as T);
       else
         rt.trigger(null);
     });
@@ -342,14 +354,14 @@ class Warehouse {
   /// <param name="name">Resource name.</param>
   /// <param name="store">IStore that manages the resource. Can be null if the resource is a store.</param>
   /// <param name="parent">Parent resource. if not presented the store becomes the parent for the resource.</param>
-  static AsyncReply<T> put<T extends IResource>(String name, T resource,
-      [IStore store = null,
-      IResource parent = null,
-      TypeTemplate customTemplate = null,
+  static AsyncReply<T?> put<T extends IResource>(String name, T resource,
+      [IStore? store = null,
+      IResource? parent = null,
+      TypeTemplate? customTemplate = null,
       int age = 0,
-      IPermissionsManager manager = null,
+      IPermissionsManager? manager = null,
       attributes = null]) {
-    var rt = AsyncReply<T>();
+    var rt = AsyncReply<T?>();
 
     if (resource.instance != null) {
       rt.triggerError(Exception("Resource has a store."));
@@ -415,19 +427,21 @@ class Warehouse {
         resourceCounter++, name, resource, store, customTemplate, age);
 
     if (attributes != null)
-      resource.instance.setAttributes(Structure.fromMap(attributes));
+      resource.instance?.setAttributes(Structure.fromMap(attributes));
 
-    if (manager != null) resource.instance.managers.add(manager);
+    if (manager != null) resource.instance?.managers.add(manager);
 
     if (store == parent) parent = null;
 
     if (parent == null) {
-      if (!(resource is IStore)) store.instance.children.add(resource);
+      if (!(resource is IStore)) store?.instance?.children.add(resource);
     } else
-      parent.instance.children.add(resource);
+      parent.instance?.children.add(resource);
 
     var initResource = () {
-      _resources[resource.instance.id] = resource;
+      if (resource.instance == null) return;
+
+      _resources[(resource.instance as Instance).id] = resource;
 
       if (_warehouseIsOpen) {
         resource.trigger(ResourceTrigger.Initialize).then<dynamic>((value) {
@@ -451,7 +465,7 @@ class Warehouse {
       _stores.add(resource);
       initResource();
     } else {
-      store.put(resource).then<dynamic>((value) {
+      store?.put(resource).then<dynamic>((value) {
         if (value)
           initResource();
         else
@@ -468,20 +482,23 @@ class Warehouse {
   }
 
   static T createInstance<T>(Type T) {
-    return _factory[T].instanceCreator.call();
+    return _factory[T]?.instanceCreator.call();
   }
 
   static List<T> createArray<T>(Type T) {
-    return _factory[T].arrayCreator.call();
+    return _factory[T]?.arrayCreator.call();
   }
 
   static AsyncReply<T> newResource<T extends IResource>(String name,
-      [IStore store = null,
-      IResource parent = null,
-      IPermissionsManager manager = null,
+      [IStore? store = null,
+      IResource? parent = null,
+      IPermissionsManager? manager = null,
       attributes = null,
       properties = null]) {
-    var resource = _factory[T].instanceCreator.call();
+    if (_factory[T] == null)
+      throw Exception("No Instance Creator was found for type ${T}");
+
+    var resource = _factory[T]?.instanceCreator.call();
 
     if (properties != null) {
       dynamic d = resource;
@@ -494,12 +511,16 @@ class Warehouse {
     var rt = AsyncReply<T>();
 
     put<T>(name, resource, store, parent, null, 0, manager, attributes)
-        .then<IResource>((value) {
+      ..then((value) {
         if (value != null)
           rt.trigger(resource);
         else
-        rt.trigger(null);
-    }).error((ex) => rt.triggerError(ex));
+          rt.triggerError(AsyncException(
+              ErrorType.Management,
+              ExceptionCode.GeneralFailure.index,
+              "Can't put the resource")); // .trigger(null);
+      })
+      ..error((ex) => rt.triggerError(ex));
 
     return rt;
 
@@ -516,7 +537,7 @@ class Warehouse {
   /// </summary>
   /// <param name="template">Resource template.</param>
   static void putTemplate(TypeTemplate template) {
-    _templates[template.type][template.classId] = template;
+    _templates[template.type]?[template.classId] = template;
   }
 
   /// <summary>
@@ -541,22 +562,22 @@ class Warehouse {
   /// </summary>
   /// <param name="classId">Class Id.</param>
   /// <returns>Resource template.</returns>
-  static TypeTemplate getTemplateByClassId(Guid classId,
+  static TypeTemplate? getTemplateByClassId(Guid classId,
       [TemplateType templateType = TemplateType.Unspecified]) {
     if (templateType == TemplateType.Unspecified) {
       // look in resources
-      var template = _templates[TemplateType.Resource][classId];
+      var template = _templates[TemplateType.Resource]?[classId];
       if (template != null) return template;
 
       // look in records
-      template = _templates[TemplateType.Record][classId];
+      template = _templates[TemplateType.Record]?[classId];
       if (template != null) return template;
 
       // look in wrappers
-      template = _templates[TemplateType.Wrapper][classId];
+      template = _templates[TemplateType.Wrapper]?[classId];
       return template;
     } else {
-      return _templates[templateType][classId];
+      return _templates[templateType]?[classId];
     }
   }
 
@@ -565,29 +586,29 @@ class Warehouse {
   /// </summary>
   /// <param name="className">Class name.</param>
   /// <returns>Resource template.</returns>
-  static TypeTemplate getTemplateByClassName(String className,
+  static TypeTemplate? getTemplateByClassName(String className,
       [TemplateType templateType = TemplateType.Unspecified]) {
     if (templateType == TemplateType.Unspecified) {
       // look in resources
       var template = _templates[TemplateType.Resource]
-          .values
+          ?.values
           .firstWhere((x) => x.className == className);
       if (template != null) return template;
 
       // look in records
       template = _templates[TemplateType.Record]
-          .values
+          ?.values
           .firstWhere((x) => x.className == className);
       if (template != null) return template;
 
       // look in wrappers
       template = _templates[TemplateType.Wrapper]
-          .values
+          ?.values
           .firstWhere((x) => x.className == className);
       return template;
     } else {
       return _templates[templateType]
-          .values
+          ?.values
           .firstWhere((x) => x.className == className);
     }
   }
@@ -595,8 +616,8 @@ class Warehouse {
   static bool remove(IResource resource) {
     if (resource.instance == null) return false;
 
-    if (_resources.containsKey(resource.instance.id))
-      _resources.remove(resource.instance.id);
+    if (_resources.containsKey(resource.instance?.id))
+      _resources.remove(resource.instance?.id);
     else
       return false;
 
@@ -605,14 +626,14 @@ class Warehouse {
 
       // remove all objects associated with the store
       var toBeRemoved =
-          _resources.values.where((x) => x.instance.store == resource);
+          _resources.values.where((x) => x.instance?.store == resource);
       for (var o in toBeRemoved) remove(o);
 
       // StoreDisconnected?.Invoke(resource as IStore);
     }
 
-    if (resource.instance.store != null)
-      resource.instance.store.remove(resource);
+    if (resource.instance?.store != null)
+      resource.instance?.store?.remove(resource);
 
     resource.destroy();
 

lib/src/Security/Authority/Authentication.dart

@@ -27,27 +27,20 @@ import 'AuthenticationMethod.dart';
 import 'AuthenticationType.dart';
 import 'Source.dart';
 
-class Authentication
-{
+class Authentication {
+  int? tokenIndex;
+  AuthenticationMethod method = AuthenticationMethod.None;
 
-    int tokenIndex;
-    AuthenticationMethod method;
-
-    String username;
+  String? username;
   //Certificate certificate;
-    String domain;
+  String? domain;
 
-    String get fullName => username + "@" + domain;
-    int state;
-
-    Source source = new Source();
+  String get fullName => (username ?? '') + '@' + (domain ?? '');
+  int state = 0;
 
+  Source? source;
 
   final AuthenticationType type;
 
-    Authentication(this.type)
-    {
-
-    }
+  Authentication(this.type) {}
 }
-

lib/src/Security/Authority/Session.dart

@@ -31,7 +31,7 @@ class Session
     Authentication get remoteAuthentication => _remoteAuth;
 
     // public Source Source { get; }
-    DC id;
+    DC? id;
 
     //DateTime get creation => _creation;
 
@@ -45,10 +45,8 @@ class Session
     Authentication _localAuth, _remoteAuth;
     
 
-    Session(Authentication localAuthentication, Authentication remoteAuthentication)
+    Session(this._localAuth, this._remoteAuth)
     {
           
-        this._localAuth = localAuthentication;
-        this._remoteAuth = remoteAuthentication;
     }
 }

lib/src/Security/Authority/Source.dart

@@ -25,22 +25,12 @@ SOFTWARE.
 import '../../Data/KeyList.dart';
 import 'SourceAttributeType.dart';
 
-class Source
-{
-
+class Source {
   //string id;
   String id;
 
-    KeyList<SourceAttributeType, dynamic> attributes;
-
-    Source.from(this.id, this.attributes)
-    {
-
-    }
-
-    Source()
-    {
-        attributes = new KeyList<SourceAttributeType, dynamic>();
-    }
+  KeyList<SourceAttributeType, dynamic> attributes =
+      new KeyList<SourceAttributeType, dynamic>();
 
+  Source.from(this.id, this.attributes) {}
 }

lib/src/Security/Integrity/SHA256.dart

@@ -2,22 +2,17 @@ import '../../Data/DC.dart';
 import '../../Data/BinaryList.dart';
 import 'dart:typed_data';
 
-class SHA256
-{
-
-    static int RROT(int n, int d)
-    {
+class SHA256 {
+  static int RROT(int n, int d) {
     return ZSHIFT(n, d) | (n << (32 - d));
   }
 
   // Zero-fill right shift
-    static int ZSHIFT(int n, int d)
-    {
+  static int ZSHIFT(int n, int d) {
     return (n & 0xFFFFFFFF) >> d;
   }
 
-    static DC compute(DC msg)
-    {
+  static DC compute(DC msg) {
     /*
         Note 1: All variables are 32 bit unsigned integers and addition is calculated modulo 2^32
         Note 2: For each round, there is one round constant k[i] and one entry in the message schedule array w[i], 0 ≤ i ≤ 63
@@ -30,22 +25,85 @@ class SHA256
     // Initialize hash values:
     // (first 32 bits of the fractional parts of the square roots of the first 8 primes 2..19):
 
-        var hash = new Uint32List.fromList([0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f,
-                                            0x9b05688c, 0x1f83d9ab, 0x5be0cd19 ]);
+    var hash = new Uint32List.fromList([
+      0x6a09e667,
+      0xbb67ae85,
+      0x3c6ef372,
+      0xa54ff53a,
+      0x510e527f,
+      0x9b05688c,
+      0x1f83d9ab,
+      0x5be0cd19
+    ]);
 
     // Initialize array of round constants:
     // (first 32 bits of the fractional parts of the cube roots of the first 64 primes 2..311):
     var k = new Uint32List.fromList([
-            0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
-            0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
-            0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
-            0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
-            0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
-            0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
-            0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
-            0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 ]);
-
-
+      0x428a2f98,
+      0x71374491,
+      0xb5c0fbcf,
+      0xe9b5dba5,
+      0x3956c25b,
+      0x59f111f1,
+      0x923f82a4,
+      0xab1c5ed5,
+      0xd807aa98,
+      0x12835b01,
+      0x243185be,
+      0x550c7dc3,
+      0x72be5d74,
+      0x80deb1fe,
+      0x9bdc06a7,
+      0xc19bf174,
+      0xe49b69c1,
+      0xefbe4786,
+      0x0fc19dc6,
+      0x240ca1cc,
+      0x2de92c6f,
+      0x4a7484aa,
+      0x5cb0a9dc,
+      0x76f988da,
+      0x983e5152,
+      0xa831c66d,
+      0xb00327c8,
+      0xbf597fc7,
+      0xc6e00bf3,
+      0xd5a79147,
+      0x06ca6351,
+      0x14292967,
+      0x27b70a85,
+      0x2e1b2138,
+      0x4d2c6dfc,
+      0x53380d13,
+      0x650a7354,
+      0x766a0abb,
+      0x81c2c92e,
+      0x92722c85,
+      0xa2bfe8a1,
+      0xa81a664b,
+      0xc24b8b70,
+      0xc76c51a3,
+      0xd192e819,
+      0xd6990624,
+      0xf40e3585,
+      0x106aa070,
+      0x19a4c116,
+      0x1e376c08,
+      0x2748774c,
+      0x34b0bcb5,
+      0x391c0cb3,
+      0x4ed8aa4a,
+      0x5b9cca4f,
+      0x682e6ff3,
+      0x748f82ee,
+      0x78a5636f,
+      0x84c87814,
+      0x8cc70208,
+      0x90befffa,
+      0xa4506ceb,
+      0xbef9a3f7,
+      0xc67178f2
+    ]);
 
     // Pre-processing:
     // begin with the original message of length L bits
@@ -56,16 +114,17 @@ class SHA256
 
     var K = 512 - ((L + 1 + 64) % 512);
 
-        if (K == 512)
-            K = 0;
+    if (K == 512) K = 0;
 
     var paddingLength = (K + 1) ~/ 8;
     var paddingBytes = new DC(paddingLength);
     paddingBytes[0] = 0x80;
 
-        var data = new BinaryList().addDC(msg).addDC(paddingBytes).addUint64(L).toDC();
-
-
+    var data = (BinaryList()
+          ..addDC(msg)
+          ..addDC(paddingBytes)
+          ..addUint64(L))
+        .toDC();
 
     // append L as a 64-bit big-endian integer, making the total post-processed length a multiple of 512 bits
 
@@ -73,15 +132,13 @@ class SHA256
     // break message into 512-bit chunks
     // for each chunk
 
-        for (var chunk = 0; chunk < data.length; chunk += 64)
-        {
+    for (var chunk = 0; chunk < data.length; chunk += 64) {
       // create a 64-entry message schedule array w[0..63] of 32-bit words
       // (The initial values in w[0..63] don't matter, so many implementations zero them here)
       // copy chunk into first 16 words w[0..15] of the message schedule array
 
-            var w = new Uint64List(64);// uint[64];
-            for (var i = 0; i < 16; i++)
-                w[i] = data.getUint32(chunk + (i * 4));
+      var w = new Uint64List(64); // uint[64];
+      for (var i = 0; i < 16; i++) w[i] = data.getUint32(chunk + (i * 4));
 
       //for(var i = 16; i < 64; i++)
       //  w[i] = 0;
@@ -92,10 +149,13 @@ class SHA256
       //        s1 := (w[i-2] rightrotate 17) xor (w[i-2] rightrotate 19) xor (w[i-2] rightshift 10)
       //        w[i] := w[i-16] + s0 + w[i-7] + s1
 
-            for (var i = 16; i < 64; i++)
-            {
-                var s0 = SHA256.RROT(w[i - 15], 7) ^ SHA256.RROT(w[i - 15], 18) ^ ZSHIFT(w[i - 15], 3);
-                var s1 = SHA256.RROT(w[i - 2], 17) ^ SHA256.RROT(w[i - 2], 19) ^ ZSHIFT(w[i - 2], 10);
+      for (var i = 16; i < 64; i++) {
+        var s0 = SHA256.RROT(w[i - 15], 7) ^
+            SHA256.RROT(w[i - 15], 18) ^
+            ZSHIFT(w[i - 15], 3);
+        var s1 = SHA256.RROT(w[i - 2], 17) ^
+            SHA256.RROT(w[i - 2], 19) ^
+            ZSHIFT(w[i - 2], 10);
         w[i] = w[i - 16] + s0 + w[i - 7] + s1;
       }
 
@@ -109,10 +169,8 @@ class SHA256
       var g = hash[6];
       var h = hash[7];
 
-
       // Compression function main loop:
-            for (var i = 0; i < 64; i++)
-            {
+      for (var i = 0; i < 64; i++) {
         var S1 = SHA256.RROT(e, 6) ^ SHA256.RROT(e, 11) ^ SHA256.RROT(e, 25);
         var ch = (e & f) ^ ((~e) & g);
         var temp1 = h + S1 + ch + k[i] + w[i];
@@ -133,27 +191,20 @@ class SHA256
       // Add the compressed chunk to the current hash value:
 
       hash[0] = ZSHIFT(hash[0] + a, 0);
-            hash[1] = ZSHIFT(hash[1] + b , 0);
-            hash[2] = ZSHIFT(hash[2] + c , 0);
-            hash[3] = ZSHIFT(hash[3] + d , 0);
-            hash[4] = ZSHIFT(hash[4] + e , 0);
-            hash[5] = ZSHIFT(hash[5] + f , 0);
-            hash[6] = ZSHIFT(hash[6] + g , 0);
+      hash[1] = ZSHIFT(hash[1] + b, 0);
+      hash[2] = ZSHIFT(hash[2] + c, 0);
+      hash[3] = ZSHIFT(hash[3] + d, 0);
+      hash[4] = ZSHIFT(hash[4] + e, 0);
+      hash[5] = ZSHIFT(hash[5] + f, 0);
+      hash[6] = ZSHIFT(hash[6] + g, 0);
       hash[7] = ZSHIFT(hash[7] + h, 0);
-
-
     }
 
-
-
-
     // Produce the final hash value (big-endian):
     //digest := hash := h0 append h1 append h2 append h3 append h4 append h5 append h6 append h7
 
     var results = new BinaryList();
-        for (var i = 0; i < 8; i++)
-            results.addUint32(hash[i]);
-
+    for (var i = 0; i < 8; i++) results.addUint32(hash[i]);
 
     return results.toDC();
   }

pubspec.lock

@@ -7,28 +7,28 @@ packages:
       name: _fe_analyzer_shared
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "22.0.0"
+    version: "23.0.0"
   analyzer:
     dependency: transitive
     description:
       name: analyzer
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.1"
+    version: "2.0.0"
   args:
     dependency: "direct main"
     description:
       name: args
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.0"
+    version: "2.2.0"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.7.0"
+    version: "2.8.1"
   boolean_selector:
     dependency: transitive
     description:
@@ -42,7 +42,7 @@ packages:
       name: build
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.2"
+    version: "2.0.3"
   charcode:
     dependency: transitive
     description:
@@ -63,7 +63,7 @@ packages:
       name: cli_util
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.0"
+    version: "0.3.3"
   collection:
     dependency: transitive
     description:
@@ -77,14 +77,14 @@ packages:
       name: convert
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.0"
+    version: "3.0.1"
   coverage:
     dependency: transitive
     description:
       name: coverage
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.15.2"
+    version: "1.0.3"
   crypto:
     dependency: transitive
     description:
@@ -98,7 +98,7 @@ packages:
       name: dart_style
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.1"
+    version: "2.0.3"
   file:
     dependency: transitive
     description:
@@ -106,6 +106,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "6.1.2"
+  frontend_server_client:
+    dependency: transitive
+    description:
+      name: frontend_server_client
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.0"
   glob:
     dependency: transitive
     description:
@@ -119,21 +126,21 @@ packages:
       name: http_multi_server
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.2.0"
+    version: "3.0.1"
   http_parser:
     dependency: transitive
     description:
       name: http_parser
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.1.3"
+    version: "4.0.0"
   io:
     dependency: transitive
     description:
       name: io
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.3"
+    version: "1.0.3"
   js:
     dependency: transitive
     description:
@@ -147,7 +154,7 @@ packages:
       name: json_annotation
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.0.1"
+    version: "4.1.0"
   logging:
     dependency: transitive
     description:
@@ -168,21 +175,21 @@ packages:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0"
+    version: "1.7.0"
   mime:
     dependency: transitive
     description:
       name: mime
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.9.6+3"
+    version: "1.0.0"
   node_preamble:
     dependency: transitive
     description:
       name: node_preamble
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.8"
+    version: "2.0.1"
   package_config:
     dependency: transitive
     description:
@@ -231,35 +238,35 @@ packages:
       name: shelf
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.7.5"
+    version: "1.2.0"
   shelf_packages_handler:
     dependency: transitive
     description:
       name: shelf_packages_handler
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "3.0.0"
   shelf_static:
     dependency: transitive
     description:
       name: shelf_static
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.9+2"
+    version: "1.1.0"
   shelf_web_socket:
     dependency: transitive
     description:
       name: shelf_web_socket
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.3"
+    version: "1.0.1"
   source_gen:
     dependency: "direct main"
     description:
       name: source_gen
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.2"
+    version: "1.0.5"
   source_map_stack_trace:
     dependency: transitive
     description:
@@ -315,21 +322,21 @@ packages:
       name: test
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.16.5"
+    version: "1.17.10"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19"
+    version: "0.4.2"
   test_core:
     dependency: transitive
     description:
       name: test_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.15"
+    version: "0.4.0"
   typed_data:
     dependency: transitive
     description:
@@ -343,7 +350,7 @@ packages:
       name: vm_service
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.0.0"
+    version: "7.1.1"
   watcher:
     dependency: transitive
     description:
@@ -357,7 +364,7 @@ packages:
       name: web_socket_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "2.1.0"
   webkit_inspection_protocol:
     dependency: transitive
     description:

pubspec.yaml

@@ -1,20 +1,20 @@
 name: esiur
 description: Distributed Object Framework.
-version: 1.4.0
+version: 1.4.1
 #author: Ahmed Zamil <ahmed@esiur.com>
 homepage: https://github.com/esiur/esiur-dart
 
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
-  source_gen: ^1.0.2 
+  source_gen: 
   args: #
   pubspec_parse:
 
 dev_dependencies:
-  test: ^1.14.2
+  test: 
 
 # For information on the generic Dart part of this file, see the
 # following page: https://www.dartlang.org/tools/pub/pubspec

test/main.dart

@@ -10,31 +10,31 @@ main() async {
   }
 }
 
-// describe object
-desc(dynamic x) {
-  if (x is List) {
-    for (var i = 0; i < x.length; i++) desc(x[i]);
-  } else if (x is DistributedResource) {
-    var y = x.instance.template;
-    print("Fucntions = ${y.functions.length}\n");
-    for (var i = 0; i < y.functions.length; i++) {
-      print("Function ${y.functions[i].name} ${y.functions[i].expansion}");
-    }
-    print("------------------------------\n");
-    print("Events = ${y.events.length}\n");
-    for (var i = 0; i < y.events.length; i++) {
-      print("Events ${y.events[i].name} ${y.events[i].expansion}");
-    }
+// // describe object
+// desc(dynamic x) {
+//   if (x is List) {
+//     for (var i = 0; i < x.length; i++) desc(x[i]);
+//   } else if (x is DistributedResource) {
+//     var y = x.instance?.template;
+//     print("Fucntions = ${y.functions.length}\n");
+//     for (var i = 0; i < y.functions.length; i++) {
+//       print("Function ${y.functions[i].name} ${y.functions[i].expansion}");
+//     }
+//     print("------------------------------\n");
+//     print("Events = ${y.events.length}\n");
+//     for (var i = 0; i < y.events.length; i++) {
+//       print("Events ${y.events[i].name} ${y.events[i].expansion}");
+//     }
 
-    print("------------------------------\n");
-    print("Properties = ${y.properties.length}\n");
-    for (var i = 0; i < y.properties.length; i++) {
-      print(
-          "Property ${y.properties[i].name} ${y.properties[i].readExpansion}");
-      // recursion
-      //print("value = ${desc(x.get(y.properties[i].index))}");
-    }
-  } else {
-    print(x.toString());
-  }
-}
+//     print("------------------------------\n");
+//     print("Properties = ${y.properties.length}\n");
+//     for (var i = 0; i < y.properties.length; i++) {
+//       print(
+//           "Property ${y.properties[i].name} ${y.properties[i].readExpansion}");
+//       // recursion
+//       //print("value = ${desc(x.get(y.properties[i].index))}");
+//     }
+//   } else {
+//     print(x.toString());
+//   }
+// }