dojo.provide("dojox.widget.Iterator");
dojo.require("dijit.Declaration");

dojo.experimental("dojox.widget.Iterator"); // level: prototype, designed for dijit.chat.demo

/*
	example:
		from markup:
	|	<span dojoType="dojo.data.ItemFileReadStore" 
	|		jsId="cstore" url="countries.json"></span>
	|	
	|	<div>
	|		<div dojoType="dojox.widget.Iterator" store="cstore"
	|			query="{ name: 'A*'}">
	|			${name} is a ${type}
	|		</div>
	|	</div>

	example:
		programmatic:
	|	var store = new dojo.data.ItemFileReadStore({ url: "countries.json" });
	|	
	|	var iter = new dojox.widget.Iterator({ 
	|		store: store,
	|		template: ""
	|	});
	|		

	example:
		programmatic from an array of objects:
	|	var dataArr = [
	|		{ name: "foo", valueAttr: "bar" },
	|		{ name: "thinger", valueAttr: "blah" }
	|	];
	|	
	|	var iter = new dojox.widget.Iterator({ 
	|		data: dataArr,
	|		template: ""
	|	});

	example:
		programmatic from an array of strings:
	|	var dataArr = [
	|		{ name: "foo", valueAttr: "bar" },
	|		{ name: "thinger", valueAttr: "blah" }
	|	];
	|	
	|	var iter = new dojox.widget.Iterator({ 
	|		data: dataArr,
	|		template: ""
	|	});

*/


dojo.declare("dojox.widget.Iterator",
	[ dijit.Declaration ],
	{

	constructor: (function(){
		var ctr = 0;
		return function(){
			this.attrs = [];
			this.children = [];
			this.widgetClass = "dojox.widget.Iterator._classes._"+(ctr++);
		}
	})(),

	start: 0,
	fetchMax: 1000,
	query: { name: "*" },
	attrs: [],
	defaultValue: "",
	widgetCtor: null,
	dataValues: [], // an array of strings
	data: null, // should be a reference to an Array
	store: null,
	_srcIndex: 0,
	_srcParent: null, 

	_setSrcIndex: function(s){
		this._srcIndex = 0;
		this._srcParent = s.parentNode;
		var ts = s;
		while(ts.previousSibling){
			this._srcIndex++;
			ts = ts.previousSibling;
		};
	},

	postscript: function(p, s){
		// figure out the position of the source node in it's parent
		this._setSrcIndex(s);
		// this._srcIndex = dojo.query(">", this._srcParent).indexOf(s);

		this.inherited("postscript", arguments);
		var wc = this.widgetCtor = dojo.getObject(this.widgetClass);

		this.attrs = dojo.map(
			wc.prototype.templateString.match(/\$\{([^\s\:\}]+)(?:\:([^\s\:\}]+))?\}/g),
			function(s){ return s.slice(2, -1); }
		);
		dojo.forEach(
			this.attrs,
			function(m){ wc.prototype[m] = ""; }
		);
		this.update();
	},

	clear: function(){
		if(this.children.length){
			this._setSrcIndex(this.children[0].domNode);
		}
		dojo.forEach(this.children, "item.destroy();");
		this.children = [];
	},

	update: function(){
		if(this.store){
			// we're executing a query
			this.fetch();
		}else{
			// we came from an array of objects. Easier!
			this.onDataAvailable(this.data||this.dataValues);
		}
	},

	_addItem: function(/*Object*/config, idx){
		if(dojo.isString(config)){
			config = { value: config };
		}
		var widget = new this.widgetCtor(config);
		this.children.push(widget);
		dojo.place(widget.domNode, this._srcParent, this._srcIndex+idx);
	},

	getAttrValuesObj: function(item){
		var obj = {};
		if(dojo.isString(item)){
			dojo.forEach(this.attrs, function(attr){
				obj[attr] = (attr == "value") ? item : this.defaultValue;
			}, this);
		}else{
			dojo.forEach(this.attrs, function(attr){
				if(this.store){
					obj[attr] = this.store.getValue(item, attr)||this.defaultValue;
				}else{
					obj[attr] = item[attr]||this.defaultValue;
				}
			}, this);
		}
		return obj;
	},

	onDataAvailable: function(data){
		this.clear();
		// console.debug(data);
		dojo.forEach(data, function(item, idx){
			this._addItem(this.getAttrValuesObj(item), idx);
		}, this);
	},

	fetch: function(query, start, end){
		this.store.fetch({
			query: query||this.query,
			start: start||this.start,
			count: end||this.fetchMax,
			onComplete: dojo.hitch(this,"onDataAvailable")
		});
	}
});

dojox.widget.Iterator._classes = {};