path: root/lib/dijit/_WidgetBase.js

/*
	Copyright (c) 2004-2011, The Dojo Foundation All Rights Reserved.
	Available via Academic Free License >= 2.1 OR the modified BSD license.
	see: http://dojotoolkit.org/license for details
*/


if(!dojo._hasResource["dijit._WidgetBase"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dijit._WidgetBase"] = true;
dojo.provide("dijit._WidgetBase");
dojo.require("dijit._base.manager");
dojo.require("dojo.Stateful");


(function(){

dojo.declare("dijit._WidgetBase", dojo.Stateful, {
	// summary:
	//		Future base class for all Dijit widgets.
	//		_Widget extends this class adding support for various features needed by desktop.

	// id: [const] String
	//		A unique, opaque ID string that can be assigned by users or by the
	//		system. If the developer passes an ID which is known not to be
	//		unique, the specified ID is ignored and the system-generated ID is
	//		used instead.
	id: "",

	// lang: [const] String
	//		Rarely used.  Overrides the default Dojo locale used to render this widget,
	//		as defined by the [HTML LANG](http://www.w3.org/TR/html401/struct/dirlang.html#adef-lang) attribute.
	//		Value must be among the list of locales specified during by the Dojo bootstrap,
	//		formatted according to [RFC 3066](http://www.ietf.org/rfc/rfc3066.txt) (like en-us).
	lang: "",

	// dir: [const] String
	//		Bi-directional support, as defined by the [HTML DIR](http://www.w3.org/TR/html401/struct/dirlang.html#adef-dir)
	//		attribute. Either left-to-right "ltr" or right-to-left "rtl".  If undefined, widgets renders in page's
	//		default direction.
	dir: "",

	// class: String
	//		HTML class attribute
	"class": "",

	// style: String||Object
	//		HTML style attributes as cssText string or name/value hash
	style: "",

	// title: String
	//		HTML title attribute.
	//
	//		For form widgets this specifies a tooltip to display when hovering over
	//		the widget (just like the native HTML title attribute).
	//
	//		For TitlePane or for when this widget is a child of a TabContainer, AccordionContainer,
	//		etc., it's used to specify the tab label, accordion pane title, etc.
	title: "",

	// tooltip: String
	//		When this widget's title attribute is used to for a tab label, accordion pane title, etc.,
	//		this specifies the tooltip to appear when the mouse is hovered over that text.
	tooltip: "",

	// baseClass: [protected] String
	//		Root CSS class of the widget (ex: dijitTextBox), used to construct CSS classes to indicate
	//		widget state.
	baseClass: "",

	// srcNodeRef: [readonly] DomNode
	//		pointer to original DOM node
	srcNodeRef: null,

	// domNode: [readonly] DomNode
	//		This is our visible representation of the widget! Other DOM
	//		Nodes may by assigned to other properties, usually through the
	//		template system's dojoAttachPoint syntax, but the domNode
	//		property is the canonical "top level" node in widget UI.
	domNode: null,

	// containerNode: [readonly] DomNode
	//		Designates where children of the source DOM node will be placed.
	//		"Children" in this case refers to both DOM nodes and widgets.
	//		For example, for myWidget:
	//
	//		|	<div dojoType=myWidget>
	//		|		<b> here's a plain DOM node
	//		|		<span dojoType=subWidget>and a widget</span>
	//		|		<i> and another plain DOM node </i>
	//		|	</div>
	//
	//		containerNode would point to:
	//
	//		|		<b> here's a plain DOM node
	//		|		<span dojoType=subWidget>and a widget</span>
	//		|		<i> and another plain DOM node </i>
	//
	//		In templated widgets, "containerNode" is set via a
	//		dojoAttachPoint assignment.
	//
	//		containerNode must be defined for any widget that accepts innerHTML
	//		(like ContentPane or BorderContainer or even Button), and conversely
	//		is null for widgets that don't, like TextBox.
	containerNode: null,

/*=====
	// _started: Boolean
	//		startup() has completed.
	_started: false,
=====*/

	// attributeMap: [protected] Object
	//		attributeMap sets up a "binding" between attributes (aka properties)
	//		of the widget and the widget's DOM.
	//		Changes to widget attributes listed in attributeMap will be
	//		reflected into the DOM.
	//
	//		For example, calling set('title', 'hello')
	//		on a TitlePane will automatically cause the TitlePane's DOM to update
	//		with the new title.
	//
	//		attributeMap is a hash where the key is an attribute of the widget,
	//		and the value reflects a binding to a:
	//
	//		- DOM node attribute
	// |		focus: {node: "focusNode", type: "attribute"}
	// 		Maps this.focus to this.focusNode.focus
	//
	//		- DOM node innerHTML
	//	|		title: { node: "titleNode", type: "innerHTML" }
	//		Maps this.title to this.titleNode.innerHTML
	//
	//		- DOM node innerText
	//	|		title: { node: "titleNode", type: "innerText" }
	//		Maps this.title to this.titleNode.innerText
	//
	//		- DOM node CSS class
	// |		myClass: { node: "domNode", type: "class" }
	//		Maps this.myClass to this.domNode.className
	//
	//		If the value is an array, then each element in the array matches one of the
	//		formats of the above list.
	//
	//		There are also some shorthands for backwards compatibility:
	//		- string --> { node: string, type: "attribute" }, for example:
	//	|	"focusNode" ---> { node: "focusNode", type: "attribute" }
	//		- "" --> { node: "domNode", type: "attribute" }
	attributeMap: {id:"", dir:"", lang:"", "class":"", style:"", title:""},

	// _blankGif: [protected] String
	//		Path to a blank 1x1 image.
	//		Used by <img> nodes in templates that really get their image via CSS background-image.
	_blankGif: (dojo.config.blankGif || dojo.moduleUrl("dojo", "resources/blank.gif")).toString(),

	//////////// INITIALIZATION METHODS ///////////////////////////////////////

	postscript: function(/*Object?*/params, /*DomNode|String*/srcNodeRef){
		// summary:
		//		Kicks off widget instantiation.  See create() for details.
		// tags:
		//		private
		this.create(params, srcNodeRef);
	},

	create: function(/*Object?*/params, /*DomNode|String?*/srcNodeRef){
		// summary:
		//		Kick off the life-cycle of a widget
		// params:
		//		Hash of initialization parameters for widget, including
		//		scalar values (like title, duration etc.) and functions,
		//		typically callbacks like onClick.
		// srcNodeRef:
		//		If a srcNodeRef (DOM node) is specified:
		//			- use srcNodeRef.innerHTML as my contents
		//			- if this is a behavioral widget then apply behavior
		//			  to that srcNodeRef
		//			- otherwise, replace srcNodeRef with my generated DOM
		//			  tree
		// description:
		//		Create calls a number of widget methods (postMixInProperties, buildRendering, postCreate,
		//		etc.), some of which of you'll want to override. See http://docs.dojocampus.org/dijit/_Widget
		//		for a discussion of the widget creation lifecycle.
		//
		//		Of course, adventurous developers could override create entirely, but this should
		//		only be done as a last resort.
		// tags:
		//		private

		// store pointer to original DOM tree
		this.srcNodeRef = dojo.byId(srcNodeRef);

		// For garbage collection.  An array of handles returned by Widget.connect()
		// Each handle returned from Widget.connect() is an array of handles from dojo.connect()
		this._connects = [];

		// For garbage collection.  An array of handles returned by Widget.subscribe()
		// The handle returned from Widget.subscribe() is the handle returned from dojo.subscribe()
		this._subscribes = [];

		// mix in our passed parameters
		if(this.srcNodeRef && (typeof this.srcNodeRef.id == "string")){ this.id = this.srcNodeRef.id; }
		if(params){
			this.params = params;
			dojo._mixin(this, params);
		}
		this.postMixInProperties();

		// generate an id for the widget if one wasn't specified
		// (be sure to do this before buildRendering() because that function might
		// expect the id to be there.)
		if(!this.id){
			this.id = dijit.getUniqueId(this.declaredClass.replace(/\./g,"_"));
		}
		dijit.registry.add(this);

		this.buildRendering();

		if(this.domNode){
			// Copy attributes listed in attributeMap into the [newly created] DOM for the widget.
			// Also calls custom setters for all attributes with custom setters.
			this._applyAttributes();

			// If srcNodeRef was specified, then swap out original srcNode for this widget's DOM tree.
			// For 2.0, move this after postCreate().  postCreate() shouldn't depend on the
			// widget being attached to the DOM since it isn't when a widget is created programmatically like
			// new MyWidget({}).   See #11635.
			var source = this.srcNodeRef;
			if(source && source.parentNode && this.domNode !== source){
				source.parentNode.replaceChild(this.domNode, source);
			}
		}

		if(this.domNode){
			// Note: for 2.0 may want to rename widgetId to dojo._scopeName + "_widgetId",
			// assuming that dojo._scopeName even exists in 2.0
			this.domNode.setAttribute("widgetId", this.id);
		}
		this.postCreate();

		// If srcNodeRef has been processed and removed from the DOM (e.g. TemplatedWidget) then delete it to allow GC.
		if(this.srcNodeRef && !this.srcNodeRef.parentNode){
			delete this.srcNodeRef;
		}

		this._created = true;
	},

	_applyAttributes: function(){
		// summary:
		//		Step during widget creation to copy all widget attributes to the
		//		DOM as per attributeMap and _setXXXAttr functions.
		// description:
		//		Skips over blank/false attribute values, unless they were explicitly specified
		//		as parameters to the widget, since those are the default anyway,
		//		and setting tabIndex="" is different than not setting tabIndex at all.
		//
		//		It processes the attributes in the attribute map first, and then
		//		it goes through and processes the attributes for the _setXXXAttr
		//		functions that have been specified
		// tags:
		//		private
		var condAttrApply = function(attr, scope){
			if((scope.params && attr in scope.params) || scope[attr]){
				scope.set(attr, scope[attr]);
			}
		};

		// Do the attributes in attributeMap
		for(var attr in this.attributeMap){
			condAttrApply(attr, this);
		}

		// And also any attributes with custom setters
		dojo.forEach(this._getSetterAttributes(), function(a){
			if(!(a in this.attributeMap)){
				condAttrApply(a, this);
			}
		}, this);
	},

	_getSetterAttributes: function(){
		// summary:
		//		Returns list of attributes with custom setters for this widget
		var ctor = this.constructor;
		if(!ctor._setterAttrs){
			var r = (ctor._setterAttrs = []),
				attrs,
				proto = ctor.prototype;
			for(var fxName in proto){
				if(dojo.isFunction(proto[fxName]) && (attrs = fxName.match(/^_set([a-zA-Z]*)Attr$/)) && attrs[1]){
					r.push(attrs[1].charAt(0).toLowerCase() + attrs[1].substr(1));
				}
			}
		}
		return ctor._setterAttrs;	// String[]
	},

	postMixInProperties: function(){
		// summary:
		//		Called after the parameters to the widget have been read-in,
		//		but before the widget template is instantiated. Especially
		//		useful to set properties that are referenced in the widget
		//		template.
		// tags:
		//		protected
	},

	buildRendering: function(){
		// summary:
		//		Construct the UI for this widget, setting this.domNode
		// description:
		//		Most widgets will mixin `dijit._Templated`, which implements this
		//		method.
		// tags:
		//		protected

		if(!this.domNode){
			// Create root node if it wasn't created by _Templated
			this.domNode = this.srcNodeRef || dojo.create('div');
		}

		// baseClass is a single class name or occasionally a space-separated list of names.
		// Add those classes to the DOMNode.  If RTL mode then also add with Rtl suffix.
		// TODO: make baseClass custom setter
		if(this.baseClass){
			var classes = this.baseClass.split(" ");
			if(!this.isLeftToRight()){
				classes = classes.concat( dojo.map(classes, function(name){ return name+"Rtl"; }));
			}
			dojo.addClass(this.domNode, classes);
		}
	},

	postCreate: function(){
		// summary:
		//		Processing after the DOM fragment is created
		// description:
		//		Called after the DOM fragment has been created, but not necessarily
		//		added to the document.  Do not include any operations which rely on
		//		node dimensions or placement.
		// tags:
		//		protected
	},

	startup: function(){
		// summary:
		//		Processing after the DOM fragment is added to the document
		// description:
		//		Called after a widget and its children have been created and added to the page,
		//		and all related widgets have finished their create() cycle, up through postCreate().
		//		This is useful for composite widgets that need to control or layout sub-widgets.
		//		Many layout widgets can use this as a wiring phase.
		this._started = true;
	},

	//////////// DESTROY FUNCTIONS ////////////////////////////////

	destroyRecursive: function(/*Boolean?*/ preserveDom){
		// summary:
		// 		Destroy this widget and its descendants
		// description:
		//		This is the generic "destructor" function that all widget users
		// 		should call to cleanly discard with a widget. Once a widget is
		// 		destroyed, it is removed from the manager object.
		// preserveDom:
		//		If true, this method will leave the original DOM structure
		//		alone of descendant Widgets. Note: This will NOT work with
		//		dijit._Templated widgets.

		this._beingDestroyed = true;
		this.destroyDescendants(preserveDom);
		this.destroy(preserveDom);
	},

	destroy: function(/*Boolean*/ preserveDom){
		// summary:
		// 		Destroy this widget, but not its descendants.
		//		This method will, however, destroy internal widgets such as those used within a template.
		// preserveDom: Boolean
		//		If true, this method will leave the original DOM structure alone.
		//		Note: This will not yet work with _Templated widgets

		this._beingDestroyed = true;
		this.uninitialize();
		var d = dojo,
			dfe = d.forEach,
			dun = d.unsubscribe;
		dfe(this._connects, function(array){
			dfe(array, d.disconnect);
		});
		dfe(this._subscribes, function(handle){
			dun(handle);
		});

		// destroy widgets created as part of template, etc.
		dfe(this._supportingWidgets || [], function(w){
			if(w.destroyRecursive){
				w.destroyRecursive();
			}else if(w.destroy){
				w.destroy();
			}
		});

		this.destroyRendering(preserveDom);
		dijit.registry.remove(this.id);
		this._destroyed = true;
	},

	destroyRendering: function(/*Boolean?*/ preserveDom){
		// summary:
		//		Destroys the DOM nodes associated with this widget
		// preserveDom:
		//		If true, this method will leave the original DOM structure alone
		//		during tear-down. Note: this will not work with _Templated
		//		widgets yet.
		// tags:
		//		protected

		if(this.bgIframe){
			this.bgIframe.destroy(preserveDom);
			delete this.bgIframe;
		}

		if(this.domNode){
			if(preserveDom){
				dojo.removeAttr(this.domNode, "widgetId");
			}else{
				dojo.destroy(this.domNode);
			}
			delete this.domNode;
		}

		if(this.srcNodeRef){
			if(!preserveDom){
				dojo.destroy(this.srcNodeRef);
			}
			delete this.srcNodeRef;
		}
	},

	destroyDescendants: function(/*Boolean?*/ preserveDom){
		// summary:
		//		Recursively destroy the children of this widget and their
		//		descendants.
		// preserveDom:
		//		If true, the preserveDom attribute is passed to all descendant
		//		widget's .destroy() method. Not for use with _Templated
		//		widgets.

		// get all direct descendants and destroy them recursively
		dojo.forEach(this.getChildren(), function(widget){
			if(widget.destroyRecursive){
				widget.destroyRecursive(preserveDom);
			}
		});
	},

	uninitialize: function(){
		// summary:
		//		Stub function. Override to implement custom widget tear-down
		//		behavior.
		// tags:
		//		protected
		return false;
	},

	////////////////// GET/SET, CUSTOM SETTERS, ETC. ///////////////////

	_setClassAttr: function(/*String*/ value){
		// summary:
		//		Custom setter for the CSS "class" attribute
		// tags:
		//		protected
		var mapNode = this[this.attributeMap["class"] || 'domNode'];
		dojo.replaceClass(mapNode, value, this["class"]);
		this._set("class", value);
	},

	_setStyleAttr: function(/*String||Object*/ value){
		// summary:
		//		Sets the style attribute of the widget according to value,
		//		which is either a hash like {height: "5px", width: "3px"}
		//		or a plain string
		// description:
		//		Determines which node to set the style on based on style setting
		//		in attributeMap.
		// tags:
		//		protected

		var mapNode = this[this.attributeMap.style || 'domNode'];

		// Note: technically we should revert any style setting made in a previous call
		// to his method, but that's difficult to keep track of.

		if(dojo.isObject(value)){
			dojo.style(mapNode, value);
		}else{
			if(mapNode.style.cssText){
				mapNode.style.cssText += "; " + value;
			}else{
				mapNode.style.cssText = value;
			}
		}

		this._set("style", value);
	},

	_attrToDom: function(/*String*/ attr, /*String*/ value){
		// summary:
		//		Reflect a widget attribute (title, tabIndex, duration etc.) to
		//		the widget DOM, as specified in attributeMap.
		//		Note some attributes like "type"
		//		cannot be processed this way as they are not mutable.
		//
		// tags:
		//		private

		var commands = this.attributeMap[attr];
		dojo.forEach(dojo.isArray(commands) ? commands : [commands], function(command){

			// Get target node and what we are doing to that node
			var mapNode = this[command.node || command || "domNode"];	// DOM node
			var type = command.type || "attribute";	// class, innerHTML, innerText, or attribute

			switch(type){
				case "attribute":
					if(dojo.isFunction(value)){ // functions execute in the context of the widget
						value = dojo.hitch(this, value);
					}

					// Get the name of the DOM node attribute; usually it's the same
					// as the name of the attribute in the widget (attr), but can be overridden.
					// Also maps handler names to lowercase, like onSubmit --> onsubmit
					var attrName = command.attribute ? command.attribute :
						(/^on[A-Z][a-zA-Z]*$/.test(attr) ? attr.toLowerCase() : attr);

					dojo.attr(mapNode, attrName, value);
					break;
				case "innerText":
					mapNode.innerHTML = "";
					mapNode.appendChild(dojo.doc.createTextNode(value));
					break;
				case "innerHTML":
					mapNode.innerHTML = value;
					break;
				case "class":
					dojo.replaceClass(mapNode, value, this[attr]);
					break;
			}
		}, this);
	},

	get: function(name){
		// summary:
		//		Get a property from a widget.
		//	name:
		//		The property to get.
		// description:
		//		Get a named property from a widget. The property may
		//		potentially be retrieved via a getter method. If no getter is defined, this
		// 		just retrieves the object's property.
		// 		For example, if the widget has a properties "foo"
		//		and "bar" and a method named "_getFooAttr", calling:
		//	|	myWidget.get("foo");
		//		would be equivalent to writing:
		//	|	widget._getFooAttr();
		//		and:
		//	|	myWidget.get("bar");
		//		would be equivalent to writing:
		//	|	widget.bar;
		var names = this._getAttrNames(name);
		return this[names.g] ? this[names.g]() : this[name];
	},
	
	set: function(name, value){
		// summary:
		//		Set a property on a widget
		//	name:
		//		The property to set.
		//	value:
		//		The value to set in the property.
		// description:
		//		Sets named properties on a widget which may potentially be handled by a
		// 		setter in the widget.
		// 		For example, if the widget has a properties "foo"
		//		and "bar" and a method named "_setFooAttr", calling:
		//	|	myWidget.set("foo", "Howdy!");
		//		would be equivalent to writing:
		//	|	widget._setFooAttr("Howdy!");
		//		and:
		//	|	myWidget.set("bar", 3);
		//		would be equivalent to writing:
		//	|	widget.bar = 3;
		//
		//	set() may also be called with a hash of name/value pairs, ex:
		//	|	myWidget.set({
		//	|		foo: "Howdy",
		//	|		bar: 3
		//	|	})
		//	This is equivalent to calling set(foo, "Howdy") and set(bar, 3)

		if(typeof name === "object"){
			for(var x in name){
				this.set(x, name[x]);
			}
			return this;
		}
		var names = this._getAttrNames(name);
		if(this[names.s]){
			// use the explicit setter
			var result = this[names.s].apply(this, Array.prototype.slice.call(arguments, 1));
		}else{
			// if param is specified as DOM node attribute, copy it
			if(name in this.attributeMap){
				this._attrToDom(name, value);
			}
			this._set(name, value);
		}
		return result || this;
	},
	
	_attrPairNames: {},		// shared between all widgets
	_getAttrNames: function(name){
		// summary:
		//		Helper function for get() and set().
		//		Caches attribute name values so we don't do the string ops every time.
		// tags:
		//		private

		var apn = this._attrPairNames;
		if(apn[name]){ return apn[name]; }
		var uc = name.charAt(0).toUpperCase() + name.substr(1);
		return (apn[name] = {
			n: name+"Node",
			s: "_set"+uc+"Attr",
			g: "_get"+uc+"Attr"
		});
	},

	_set: function(/*String*/ name, /*anything*/ value){
		// summary:
		//		Helper function to set new value for specified attribute, and call handlers
		//		registered with watch() if the value has changed.
		var oldValue = this[name];
		this[name] = value;
		if(this._watchCallbacks && this._created && value !== oldValue){
			this._watchCallbacks(name, oldValue, value);
		}
	},

	toString: function(){
		// summary:
		//		Returns a string that represents the widget
		// description:
		//		When a widget is cast to a string, this method will be used to generate the
		//		output. Currently, it does not implement any sort of reversible
		//		serialization.
		return '[Widget ' + this.declaredClass + ', ' + (this.id || 'NO ID') + ']'; // String
	},

	getDescendants: function(){
		// summary:
		//		Returns all the widgets contained by this, i.e., all widgets underneath this.containerNode.
		//		This method should generally be avoided as it returns widgets declared in templates, which are
		//		supposed to be internal/hidden, but it's left here for back-compat reasons.

		return this.containerNode ? dojo.query('[widgetId]', this.containerNode).map(dijit.byNode) : []; // dijit._Widget[]
	},

	getChildren: function(){
		// summary:
		//		Returns all the widgets contained by this, i.e., all widgets underneath this.containerNode.
		//		Does not return nested widgets, nor widgets that are part of this widget's template.
		return this.containerNode ? dijit.findWidgets(this.containerNode) : []; // dijit._Widget[]
	},

	connect: function(
			/*Object|null*/ obj,
			/*String|Function*/ event,
			/*String|Function*/ method){
		// summary:
		//		Connects specified obj/event to specified method of this object
		//		and registers for disconnect() on widget destroy.
		// description:
		//		Provide widget-specific analog to dojo.connect, except with the
		//		implicit use of this widget as the target object.
		//		Events connected with `this.connect` are disconnected upon
		//		destruction.
		// returns:
		//		A handle that can be passed to `disconnect` in order to disconnect before
		//		the widget is destroyed.
		// example:
		//	|	var btn = new dijit.form.Button();
		//	|	// when foo.bar() is called, call the listener we're going to
		//	|	// provide in the scope of btn
		//	|	btn.connect(foo, "bar", function(){
		//	|		console.debug(this.toString());
		//	|	});
		// tags:
		//		protected

		var handles = [dojo._connect(obj, event, this, method)];
		this._connects.push(handles);
		return handles;		// _Widget.Handle
	},

	disconnect: function(/* _Widget.Handle */ handles){
		// summary:
		//		Disconnects handle created by `connect`.
		//		Also removes handle from this widget's list of connects.
		// tags:
		//		protected
		for(var i=0; i<this._connects.length; i++){
			if(this._connects[i] == handles){
				dojo.forEach(handles, dojo.disconnect);
				this._connects.splice(i, 1);
				return;
			}
		}
	},

	subscribe: function(
			/*String*/ topic,
			/*String|Function*/ method){
		// summary:
		//		Subscribes to the specified topic and calls the specified method
		//		of this object and registers for unsubscribe() on widget destroy.
		// description:
		//		Provide widget-specific analog to dojo.subscribe, except with the
		//		implicit use of this widget as the target object.
		// example:
		//	|	var btn = new dijit.form.Button();
		//	|	// when /my/topic is published, this button changes its label to
		//	|   // be the parameter of the topic.
		//	|	btn.subscribe("/my/topic", function(v){
		//	|		this.set("label", v);
		//	|	});
		var handle = dojo.subscribe(topic, this, method);

		// return handles for Any widget that may need them
		this._subscribes.push(handle);
		return handle;
	},

	unsubscribe: function(/*Object*/ handle){
		// summary:
		//		Unsubscribes handle created by this.subscribe.
		//		Also removes handle from this widget's list of subscriptions
		for(var i=0; i<this._subscribes.length; i++){
			if(this._subscribes[i] == handle){
				dojo.unsubscribe(handle);
				this._subscribes.splice(i, 1);
				return;
			}
		}
	},

	isLeftToRight: function(){
		// summary:
		//		Return this widget's explicit or implicit orientation (true for LTR, false for RTL)
		// tags:
		//		protected
		return this.dir ? (this.dir == "ltr") : dojo._isBodyLtr(); //Boolean
	},

	placeAt: function(/* String|DomNode|_Widget */reference, /* String?|Int? */position){
		// summary:
		//		Place this widget's domNode reference somewhere in the DOM based
		//		on standard dojo.place conventions, or passing a Widget reference that
		//		contains and addChild member.
		//
		// description:
		//		A convenience function provided in all _Widgets, providing a simple
		//		shorthand mechanism to put an existing (or newly created) Widget
		//		somewhere in the dom, and allow chaining.
		//
		// reference:
		//		The String id of a domNode, a domNode reference, or a reference to a Widget posessing
		//		an addChild method.
		//
		// position:
		//		If passed a string or domNode reference, the position argument
		//		accepts a string just as dojo.place does, one of: "first", "last",
		//		"before", or "after".
		//
		//		If passed a _Widget reference, and that widget reference has an ".addChild" method,
		//		it will be called passing this widget instance into that method, supplying the optional
		//		position index passed.
		//
		// returns:
		//		dijit._Widget
		//		Provides a useful return of the newly created dijit._Widget instance so you
		//		can "chain" this function by instantiating, placing, then saving the return value
		//		to a variable.
		//
		// example:
		// | 	// create a Button with no srcNodeRef, and place it in the body:
		// | 	var button = new dijit.form.Button({ label:"click" }).placeAt(dojo.body());
		// | 	// now, 'button' is still the widget reference to the newly created button
		// | 	dojo.connect(button, "onClick", function(e){ console.log('click'); });
		//
		// example:
		// |	// create a button out of a node with id="src" and append it to id="wrapper":
		// | 	var button = new dijit.form.Button({},"src").placeAt("wrapper");
		//
		// example:
		// |	// place a new button as the first element of some div
		// |	var button = new dijit.form.Button({ label:"click" }).placeAt("wrapper","first");
		//
		// example:
		// |	// create a contentpane and add it to a TabContainer
		// |	var tc = dijit.byId("myTabs");
		// |	new dijit.layout.ContentPane({ href:"foo.html", title:"Wow!" }).placeAt(tc)

		if(reference.declaredClass && reference.addChild){
			reference.addChild(this, position);
		}else{
			dojo.place(this.domNode, reference, position);
		}
		return this;
	}
});

})();

}