export default class RefsCollection
{

    constructor(rootElement){
        this._rootElement = rootElement;
    }

    _build(element, append) {

        if (element == undefined)
            element = this._rootElement;

        if (!append)
            for(var i in this)
                if (i != "_rootElement" && i != "_build")
                    delete this[i];

        for(var i = 0; i < element.children.length; i++)
        {
            let child = element.children[i];

            if (child.hasAttribute("ref"))
            {
                let ref = child.getAttribute("ref");
				if (this[ref] == null)
					this[ref] = child;
				else if (this[ref] == child){
					// do nothing
				}
				else if (this[ref] instanceof Array){
					this[ref].push(child);
				} else {
					var firstRef = this[ref];
					this[ref] =[firstRef, child];
				}
            }

            if (child.refs != undefined)
                // opt out if the element handles referencing
                break;
            else
                this._build(child, true);
        }
    }
}