_WidgetBase.js

define([
	"require", // require.toUrl
	"dojo/_base/array", // array.forEach array.map
	"dojo/aspect",
	"dojo/_base/config", // config.blankGif
	"dojo/_base/connect", // connect.connect
	"dojo/_base/declare", // declare
	"dojo/dom", // dom.byId
	"dojo/dom-attr", // domAttr.set domAttr.remove
	"dojo/dom-class", // domClass.add domClass.replace
	"dojo/dom-construct", // domConstruct.destroy domConstruct.place
	"dojo/dom-geometry", // isBodyLtr
	"dojo/dom-style", // domStyle.set, domStyle.get
	"dojo/has",
	"dojo/_base/kernel",
	"dojo/_base/lang", // mixin(), isArray(), etc.
	"dojo/on",
	"dojo/ready",
	"dojo/Stateful", // Stateful
	"dojo/topic",
	"dojo/_base/window", // win.body()
	"./Destroyable",
	"dojo/has!dojo-bidi?./_BidiMixin",
	"./registry"    // registry.getUniqueId(), registry.findWidgets()
], function(require, array, aspect, config, connect, declare,
			dom, domAttr, domClass, domConstruct, domGeometry, domStyle, has, kernel,
			lang, on, ready, Stateful, topic, win, Destroyable, _BidiMixin, registry){

	// module:
	//		dijit/_WidgetBase

	// Flag to make dijit load modules the app didn't explicitly request, for backwards compatibility
	has.add("dijit-legacy-requires", !kernel.isAsync);

	// Flag to enable support for textdir attribute
	has.add("dojo-bidi", false);


	// For back-compat, remove in 2.0.
	if(has("dijit-legacy-requires")){
		ready(0, function(){
			var requires = ["dijit/_base/manager"];
			require(requires);	// use indirection so modules not rolled into a build
		});
	}

	// Nested hash listing attributes for each tag, all strings in lowercase.
	// ex: {"div": {"style": true, "tabindex" true}, "form": { ...
	var tagAttrs = {};

	function getAttrs(obj){
		var ret = {};
		for(var attr in obj){
			ret[attr.toLowerCase()] = true;
		}
		return ret;
	}

	function nonEmptyAttrToDom(attr){
		// summary:
		//		Returns a setter function that copies the attribute to this.domNode,
		//		or removes the attribute from this.domNode, depending on whether the
		//		value is defined or not.
		return function(val){
			domAttr[val ? "set" : "remove"](this.domNode, attr, val);
			this._set(attr, val);
		};
	}

	function isEqual(a, b){
		//	summary:
		//		Function that determines whether two values are identical,
		//		taking into account that NaN is not normally equal to itself
		//		in JS.

		return a === b || (/* a is NaN */ a !== a && /* b is NaN */ b !== b);
	}

	var _WidgetBase = declare("dijit._WidgetBase", [Stateful, Destroyable], {
		// summary:
		//		Future base class for all Dijit widgets.
		// description:
		//		Future base class for all Dijit widgets.
		//		_Widget extends this class adding support for various features needed by desktop.
		//
		//		Provides stubs for widget lifecycle methods for subclasses to extend, like postMixInProperties(), buildRendering(),
		//		postCreate(), startup(), and destroy(), and also public API methods like set(), get(), and watch().
		//
		//		Widgets can provide custom setters/getters for widget attributes, which are called automatically by set(name, value).
		//		For an attribute XXX, define methods _setXXXAttr() and/or _getXXXAttr().
		//
		//		_setXXXAttr can also be a string/hash/array mapping from a widget attribute XXX to the widget's DOMNodes:
		//
		//		- DOM node attribute
		// |		_setFocusAttr: {node: "focusNode", type: "attribute"}
		// |		_setFocusAttr: "focusNode"	(shorthand)
		// |		_setFocusAttr: ""		(shorthand, maps to this.domNode)
		//		Maps this.focus to this.focusNode.focus, or (last example) this.domNode.focus
		//
		//		- DOM node innerHTML
		//	|		_setTitleAttr: { node: "titleNode", type: "innerHTML" }
		//		Maps this.title to this.titleNode.innerHTML
		//
		//		- DOM node innerText
		//	|		_setTitleAttr: { node: "titleNode", type: "innerText" }
		//		Maps this.title to this.titleNode.innerText
		//
		//		- DOM node CSS class
		// |		_setMyClassAttr: { node: "domNode", type: "class" }
		//		Maps this.myClass to this.domNode.className
		//
		//		If the value of _setXXXAttr is an array, then each element in the array matches one of the
		//		formats of the above list.
		//
		//		If the custom setter is null, no action is performed other than saving the new value
		//		in the widget (in this).
		//
		//		If no custom setter is defined for an attribute, then it will be copied
		//		to this.focusNode (if the widget defines a focusNode), or this.domNode otherwise.
		//		That's only done though for attributes that match DOMNode attributes (title,
		//		alt, aria-labelledby, etc.)

		// 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: "",
		_setIdAttr: "domNode", // to copy to this.domNode even for auto-generated id's

		// 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: "",
		// set on domNode even when there's a focus node.	but don't set lang="", since that's invalid.
		_setLangAttr: nonEmptyAttrToDom("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: "",
		// set on domNode even when there's a focus node.	but don't set dir="", since that's invalid.
		_setDirAttr: nonEmptyAttrToDom("dir"), // to set on domNode even when there's a focus node

		// class: String
		//		HTML class attribute
		"class": "",
		_setClassAttr: { node: "domNode", type: "class" },

		// Override automatic assigning type --> focusNode, it causes exception on IE6-8.
		// Instead, type must be specified as ${type} in the template, as part of the original DOM.
		_setTypeAttr: null,

		// 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.  In this case it's
		//		interpreted as HTML.
		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 data-dojo-attach-point 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 data-dojo-type=myWidget>
		//		|		<b> here's a plain DOM node
		//		|		<span data-dojo-type=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 data-dojo-type=subWidget>and a widget</span>
		//		|		<i> and another plain DOM node </i>
		//
		//		In templated widgets, "containerNode" is set via a
		//		data-dojo-attach-point 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,

		// ownerDocument: [const] Document?
		//		The document this widget belongs to.  If not specified to constructor, will default to
		//		srcNodeRef.ownerDocument, or if no sourceRef specified, then to the document global
		ownerDocument: null,
		_setOwnerDocumentAttr: function(val){
			// this setter is merely to avoid automatically trying to set this.domNode.ownerDocument
			this._set("ownerDocument", val);
		},

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

		// attributeMap: [protected] Object
		//		Deprecated.	Instead of attributeMap, widget should have a _setXXXAttr attribute
		//		for each XXX attribute to be mapped to the DOM.
		//
		//		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: {},

		// _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: config.blankGif || require.toUrl("dojo/resources/blank.gif"),

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

		/*=====
		constructor: function(params, srcNodeRef){
			// summary:
			//		Create the widget.
			// params: Object|null
			//		Hash of initialization parameters for widget, including scalar values (like title, duration etc.)
			//		and functions, typically callbacks like onClick.
			//		The hash can contain any of the widget's properties, excluding read-only properties.
			// srcNodeRef: DOMNode|String?
			//		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
		},
		=====*/

		_introspect: function(){
			// summary:
			//		Collect metadata about this widget (only once per class, not once per instance):
			//
			//			- list of attributes with custom setters, storing in this.constructor._setterAttrs
			//			- generate this.constructor._onMap, mapping names like "mousedown" to functions like onMouseDown

			var ctor = this.constructor;
			if(!ctor._setterAttrs){
				var proto = ctor.prototype,
					attrs = ctor._setterAttrs = [], // attributes with custom setters
					onMap = (ctor._onMap = {});

				// Items in this.attributeMap are like custom setters.  For back-compat, remove for 2.0.
				for(var name in proto.attributeMap){
					attrs.push(name);
				}

				// Loop over widget properties, collecting properties with custom setters and filling in ctor._onMap.
				for(name in proto){
					if(/^on/.test(name)){
						onMap[name.substring(2).toLowerCase()] = name;
					}

					if(/^_set[A-Z](.*)Attr$/.test(name)){
						name = name.charAt(4).toLowerCase() + name.substr(5, name.length - 9);
						if(!proto.attributeMap || !(name in proto.attributeMap)){
							attrs.push(name);
						}
					}
				}

				// Note: this isn't picking up info on properties like aria-label and role, that don't have custom setters
				// but that set() maps to attributes on this.domNode or this.focusNode
			}
		},

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

			// Note that we skip calling this.inherited(), i.e. dojo/Stateful::postscript(), because 1.x widgets don't
			// expect their custom setters to get called until after buildRendering().  Consider changing for 2.0.

			this.create(params, srcNodeRef);
		},

		create: function(params, srcNodeRef){
			// summary:
			//		Kick off the life-cycle of a widget
			// description:
			//		Create calls a number of widget methods (postMixInProperties, buildRendering, postCreate,
			//		etc.), some of which of you'll want to override. See http://dojotoolkit.org/reference-guide/dijit/_WidgetBase.html
			//		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.
			// params: Object|null
			//		Hash of initialization parameters for widget, including scalar values (like title, duration etc.)
			//		and functions, typically callbacks like onClick.
			//		The hash can contain any of the widget's properties, excluding read-only properties.
			// srcNodeRef: DOMNode|String?
			//		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
			// tags:
			//		private

			// First time widget is instantiated, scan prototype to figure out info about custom setters etc.
			this._introspect();

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

			// No longer used, remove for 2.0.
			this._connects = [];
			this._supportingWidgets = [];

			// this is here for back-compat, remove in 2.0 (but check NodeList-instantiate.html test)
			if(this.srcNodeRef && (typeof this.srcNodeRef.id == "string")){
				this.id = this.srcNodeRef.id;
			}

			// mix in our passed parameters
			if(params){
				this.params = params;
				lang.mixin(this, params);
			}
			this.postMixInProperties();

			// Generate an id for the widget if one wasn't specified, or it was specified as id: undefined.
			// Do this before buildRendering() because it might expect the id to be there.
			if(!this.id){
				this.id = registry.getUniqueId(this.declaredClass.replace(/\./g, "_"));
				if(this.params){
					// if params contains {id: undefined}, prevent _applyAttributes() from processing it
					delete this.params.id;
				}
			}

			// The document and <body> node this widget is associated with
			this.ownerDocument = this.ownerDocument || (this.srcNodeRef ? this.srcNodeRef.ownerDocument : document);
			this.ownerDocumentBody = win.body(this.ownerDocument);

			registry.add(this);

			this.buildRendering();

			var deleteSrcNodeRef;

			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);
					deleteSrcNodeRef = true;
				}

				// 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.
			// I think for back-compatibility it isn't deleting srcNodeRef until after postCreate() has run.
			if(deleteSrcNodeRef){
				delete this.srcNodeRef;
			}

			this._created = true;
		},

		_applyAttributes: function(){
			// summary:
			//		Step during widget creation to copy  widget attributes to the
			//		DOM according to attributeMap and _setXXXAttr objects, and also to call
			//		custom _setXXXAttr() methods.
			//
			//		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.
			//
			//		For backwards-compatibility reasons attributeMap overrides _setXXXAttr when
			//		_setXXXAttr is a hash/string/array, but _setXXXAttr as a functions override attributeMap.
			// tags:
			//		private

			// Call this.set() for each property that was either specified as parameter to constructor,
			// or is in the list found above.	For correlated properties like value and displayedValue, the one
			// specified as a parameter should take precedence.
			// Particularly important for new DateTextBox({displayedValue: ...}) since DateTextBox's default value is
			// NaN and thus is not ignored like a default value of "".

			// Step 1: Save the current values of the widget properties that were specified as parameters to the constructor.
			// Generally this.foo == this.params.foo, except if postMixInProperties() changed the value of this.foo.
			var params = {};
			for(var key in this.params || {}){
				params[key] = this._get(key);
			}

			// Step 2: Call set() for each property with a non-falsy value that wasn't passed as a parameter to the constructor
			array.forEach(this.constructor._setterAttrs, function(key){
				if(!(key in params)){
					var val = this._get(key);
					if(val){
						this.set(key, val);
					}
				}
			}, this);

			// Step 3: Call set() for each property that was specified as parameter to constructor.
			// Use params hash created above to ignore side effects from step #2 above.
			for(key in params){
				this.set(key, params[key]);
			}
		},

		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.
			//		Most widgets will mixin `dijit._TemplatedMixin`, which implements this method.
			// tags:
			//		protected

			if(!this.domNode){
				// Create root node if it wasn't created by _TemplatedMixin
				this.domNode = this.srcNodeRef || this.ownerDocument.createElement("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(array.map(classes, function(name){
						return name + "Rtl";
					}));
				}
				domClass.add(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().
			//
			//		Note that startup() may be called while the widget is still hidden, for example if the widget is
			//		inside a hidden dijit/Dialog or an unselected tab of a dijit/layout/TabContainer.
			//		For widgets that need to do layout, it's best to put that layout code inside resize(), and then
			//		extend dijit/layout/_LayoutWidget so that resize() is called when the widget is visible.
			if(this._started){
				return;
			}
			this._started = true;
			array.forEach(this.getChildren(), function(obj){
				if(!obj._started && !obj._destroyed && lang.isFunction(obj.startup)){
					obj.startup();
					obj._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._TemplatedMixin widgets.

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

		destroy: function(/*Boolean*/ preserveDom){
			// summary:
			//		Destroy this widget, but not its descendants.  Descendants means widgets inside of
			//		this.containerNode.   Will also destroy any resources (including widgets) registered via this.own().
			//
			//		This method will also destroy internal widgets such as those created from a template,
			//		assuming those widgets exist inside of this.domNode but outside of this.containerNode.
			//
			//		For 2.0 it's planned that this method will also destroy descendant widgets, so apps should not
			//		depend on the current ability to destroy a widget without destroying its descendants.   Generally
			//		they should use destroyRecursive() for widgets with children.
			// preserveDom: Boolean
			//		If true, this method will leave the original DOM structure alone.
			//		Note: This will not yet work with _TemplatedMixin widgets

			this._beingDestroyed = true;
			this.uninitialize();

			function destroy(w){
				if(w.destroyRecursive){
					w.destroyRecursive(preserveDom);
				}else if(w.destroy){
					w.destroy(preserveDom);
				}
			}

			// Back-compat, remove for 2.0
			array.forEach(this._connects, lang.hitch(this, "disconnect"));
			array.forEach(this._supportingWidgets, destroy);

			// Destroy supporting widgets, but not child widgets under this.containerNode (for 2.0, destroy child widgets
			// here too).   if() statement is to guard against exception if destroy() called multiple times (see #15815).
			if(this.domNode){
				array.forEach(registry.findWidgets(this.domNode, this.containerNode), destroy);
			}

			this.destroyRendering(preserveDom);
			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){
					domAttr.remove(this.domNode, "widgetId");
				}else{
					domConstruct.destroy(this.domNode);
				}
				delete this.domNode;
			}

			if(this.srcNodeRef){
				if(!preserveDom){
					domConstruct.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
			array.forEach(this.getChildren(), function(widget){
				if(widget.destroyRecursive){
					widget.destroyRecursive(preserveDom);
				}
			});
		},

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

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

		_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.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(lang.isObject(value)){
				domStyle.set(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, /*Object?*/ commands){
			// summary:
			//		Reflect a widget attribute (title, tabIndex, duration etc.) to
			//		the widget DOM, as specified by commands parameter.
			//		If commands isn't specified then it's looked up from attributeMap.
			//		Note some attributes like "type"
			//		cannot be processed this way as they are not mutable.
			// attr:
			//		Name of member variable (ex: "focusNode" maps to this.focusNode) pointing
			//		to DOMNode inside the widget, or alternately pointing to a subwidget
			// tags:
			//		private

			commands = arguments.length >= 3 ? commands : this.attributeMap[attr];

			array.forEach(lang.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(lang.isFunction(value)){ // functions execute in the context of the widget
							value = lang.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);

						if(mapNode.tagName){
							// Normal case, mapping to a DOMNode.  Note that modern browsers will have a mapNode.set()
							// method, but for consistency we still call domAttr
							domAttr.set(mapNode, attrName, value);
						}else{
							// mapping to a sub-widget
							mapNode.set(attrName, value);
						}
						break;
					case "innerText":
						mapNode.innerHTML = "";
						mapNode.appendChild(this.ownerDocument.createTextNode(value));
						break;
					case "innerHTML":
						mapNode.innerHTML = value;
						break;
					case "class":
						domClass.replace(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 properties `foo` and `bar`
			//		and a method named `_getFooAttr()`, calling:
			//		`myWidget.get("foo")` would be equivalent to calling
			//		`widget._getFooAttr()` and `myWidget.get("bar")`
			//		would be equivalent to the expression
			//		`widget.bar2`
			var names = this._getAttrNames(name);
			return this[names.g] ? this[names.g]() : this._get(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 properties `foo` and `bar`
			//		and a method named `_setFooAttr()`, calling
			//		`myWidget.set("foo", "Howdy!")` would be equivalent to calling
			//		`widget._setFooAttr("Howdy!")` and `myWidget.set("bar", 3)`
			//		would be equivalent to the statement `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),
				setter = this[names.s];
			if(lang.isFunction(setter)){
				// use the explicit setter
				var result = setter.apply(this, Array.prototype.slice.call(arguments, 1));
			}else{
				// Mapping from widget attribute to DOMNode/subwidget attribute/value/etc.
				// Map according to:
				//		1. attributeMap setting, if one exists (TODO: attributeMap deprecated, remove in 2.0)
				//		2. _setFooAttr: {...} type attribute in the widget (if one exists)
				//		3. apply to focusNode or domNode if standard attribute name, excluding funcs like onClick.
				// Checks if an attribute is a "standard attribute" by whether the DOMNode JS object has a similar
				// attribute name (ex: accept-charset attribute matches jsObject.acceptCharset).
				// Note also that Tree.focusNode() is a function not a DOMNode, so test for that.
				var defaultNode = this.focusNode && !lang.isFunction(this.focusNode) ? "focusNode" : "domNode",
					tag = this[defaultNode] && this[defaultNode].tagName,
					attrsForTag = tag && (tagAttrs[tag] || (tagAttrs[tag] = getAttrs(this[defaultNode]))),
					map = name in this.attributeMap ? this.attributeMap[name] :
						names.s in this ? this[names.s] :
							((attrsForTag && names.l in attrsForTag && typeof value != "function") ||
								/^aria-|^data-|^role$/.test(name)) ? defaultNode : null;
				if(map != null){
					this._attrToDom(name, value, map);
				}
				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.replace(/^[a-z]|-[a-zA-Z]/g, function(c){
				return c.charAt(c.length - 1).toUpperCase();
			});
			return (apn[name] = {
				n: name + "Node",
				s: "_set" + uc + "Attr", // converts dashes to camel case, ex: accept-charset --> _setAcceptCharsetAttr
				g: "_get" + uc + "Attr",
				l: uc.toLowerCase()        // lowercase name w/out dashes, ex: acceptcharset
			});
		},

		_set: function(/*String*/ name, /*anything*/ value){
			// summary:
			//		Helper function to set new value for specified property, and call handlers
			//		registered with watch() if the value has changed.
			var oldValue = this[name];
			this[name] = value;
			if(this._created && !isEqual(oldValue, value)){
				if(this._watchCallbacks){
					this._watchCallbacks(name, oldValue, value);
				}
				this.emit("attrmodified-" + name, {
					detail: {
						prevValue: oldValue,
						newValue: value
					}
				});
			}
		},

		_get: function(/*String*/ name){
			// summary:
			//		Helper function to get value for specified property stored by this._set(),
			//		i.e. for properties with custom setters.  Used mainly by custom getters.
			//
			//		For example, CheckBox._getValueAttr() calls this._get("value").

			// future: return name in this.props ? this.props[name] : this[name];
			return this[name];
		},

		emit: function(/*String*/ type, /*Object?*/ eventObj, /*Array?*/ callbackArgs){
			// summary:
			//		Used by widgets to signal that a synthetic event occurred, ex:
			//	|	myWidget.emit("attrmodified-selectedChildWidget", {}).
			//
			//		Emits an event on this.domNode named type.toLowerCase(), based on eventObj.
			//		Also calls onType() method, if present, and returns value from that method.
			//		By default passes eventObj to callback, but will pass callbackArgs instead, if specified.
			//		Modifies eventObj by adding missing parameters (bubbles, cancelable, widget).
			// tags:
			//		protected

			// Specify fallback values for bubbles, cancelable in case they are not set in eventObj.
			// Also set pointer to widget, although since we can't add a pointer to the widget for native events
			// (see #14729), maybe we shouldn't do it here?
			eventObj = eventObj || {};
			if(eventObj.bubbles === undefined){
				eventObj.bubbles = true;
			}
			if(eventObj.cancelable === undefined){
				eventObj.cancelable = true;
			}
			if(!eventObj.detail){
				eventObj.detail = {};
			}
			eventObj.detail.widget = this;

			var ret, callback = this["on" + type];
			if(callback){
				ret = callback.apply(this, callbackArgs ? callbackArgs : [eventObj]);
			}

			// Emit event, but avoid spurious emit()'s as parent sets properties on child during startup/destroy
			if(this._started && !this._beingDestroyed){
				on.emit(this.domNode, type.toLowerCase(), eventObj);
			}

			return ret;
		},

		on: function(/*String|Function*/ type, /*Function*/ func){
			// summary:
			//		Call specified function when event occurs, ex: myWidget.on("click", function(){ ... }).
			// type:
			//		Name of event (ex: "click") or extension event like touch.press.
			// description:
			//		Call specified function when event `type` occurs, ex: `myWidget.on("click", function(){ ... })`.
			//		Note that the function is not run in any particular scope, so if (for example) you want it to run in the
			//		widget's scope you must do `myWidget.on("click", lang.hitch(myWidget, func))`.

			// For backwards compatibility, if there's an onType() method in the widget then connect to that.
			// Remove in 2.0.
			var widgetMethod = this._onMap(type);
			if(widgetMethod){
				return aspect.after(this, widgetMethod, func, true);
			}

			// Otherwise, just listen for the event on this.domNode.
			
			// We lowercase the event type so as to mimic the behaviour of emit
			if (typeof type === 'string') {
				type = type.toLowerCase();
			}
			
			return this.own(on(this.domNode, type, func))[0];
		},

		_onMap: function(/*String|Function*/ type){
			// summary:
			//		Maps on() type parameter (ex: "mousemove") to method name (ex: "onMouseMove").
			//		If type is a synthetic event like touch.press then returns undefined.
			var ctor = this.constructor, map = ctor._onMap;
			if(!map){
				map = (ctor._onMap = {});
				for(var attr in ctor.prototype){
					if(/^on/.test(attr)){
						map[attr.replace(/^on/, "").toLowerCase()] = attr;
					}
				}
			}
			return map[typeof type == "string" && type.toLowerCase()];	// String
		},

		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
		},

		getChildren: function(){
			// summary:
			//		Returns all direct children of this widget, i.e. all widgets underneath this.containerNode whose parent
			//		is this widget.   Note that it does not return all descendants, but rather just direct children.
			//		Analogous to [Node.childNodes](https://developer.mozilla.org/en-US/docs/DOM/Node.childNodes),
			//		except containing widgets rather than DOMNodes.
			//
			//		The result intentionally excludes internally created widgets (a.k.a. supporting widgets)
			//		outside of this.containerNode.
			//
			//		Note that the array returned is a simple array.  Application code should not assume
			//		existence of methods like forEach().

			return this.containerNode ? registry.findWidgets(this.containerNode) : []; // dijit/_WidgetBase[]
		},

		getParent: function(){
			// summary:
			//		Returns the parent widget of this widget.

			return registry.getEnclosingWidget(this.domNode.parentNode);
		},

		connect: function(/*Object|null*/ obj, /*String|Function*/ event, /*String|Function*/ method){
			// summary:
			//		Deprecated, will be removed in 2.0, use this.own(on(...)) or this.own(aspect.after(...)) instead.
			//
			//		Connects specified obj/event to specified method of this object
			//		and registers for disconnect() on widget destroy.
			//
			//		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 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

			return this.own(connect.connect(obj, event, this, method))[0];	// handle
		},

		disconnect: function(handle){
			// summary:
			//		Deprecated, will be removed in 2.0, use handle.remove() instead.
			//
			//		Disconnects handle created by `connect`.
			// tags:
			//		protected

			handle.remove();
		},

		subscribe: function(t, method){
			// summary:
			//		Deprecated, will be removed in 2.0, use this.own(topic.subscribe()) instead.
			//
			//		Subscribes to the specified topic and calls the specified method
			//		of this object and registers for unsubscribe() on widget destroy.
			//
			//		Provide widget-specific analog to dojo.subscribe, except with the
			//		implicit use of this widget as the target object.
			// t: String
			//		The topic
			// method: Function
			//		The callback
			// example:
			//	|	var btn = new 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);
			//	|	});
			// tags:
			//		protected
			return this.own(topic.subscribe(t, lang.hitch(this, method)))[0];	// handle
		},

		unsubscribe: function(/*Object*/ handle){
			// summary:
			//		Deprecated, will be removed in 2.0, use handle.remove() instead.
			//
			//		Unsubscribes handle created by this.subscribe.
			//		Also removes handle from this widget's list of subscriptions
			// tags:
			//		protected

			handle.remove();
		},

		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") : domGeometry.isBodyLtr(this.ownerDocument); //Boolean
		},

		isFocusable: function(){
			// summary:
			//		Return true if this widget can currently be focused
			//		and false if not
			return this.focus && (domStyle.get(this.domNode, "display") != "none");
		},

		placeAt: function(/*String|DomNode|DocumentFragment|dijit/_WidgetBase*/ reference, /*String|Int?*/ position){
			// summary:
			//		Place this widget somewhere in the DOM based
			//		on standard domConstruct.place() conventions.
			// 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:
			//		Widget, DOMNode, DocumentFragment, or id of widget or DOMNode
			// position:
			//		If reference is a widget (or id of widget), and that widget has an ".addChild" method,
			//		it will be called passing this widget instance into that method, supplying the optional
			//		position index passed.  In this case position (if specified) should be an integer.
			//
			//		If reference is a DOMNode (or id matching a DOMNode but not a widget),
			//		the position argument can be a numeric index or a string
			//		"first", "last", "before", or "after", same as dojo/dom-construct::place().
			// returns: dijit/_WidgetBase
			//		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 Button({ label:"click" }).placeAt(win.body());
			//	|	// now, 'button' is still the widget reference to the newly created button
			//	|	button.on("click", 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 Button({},"src").placeAt("wrapper");
			// example:
			//	|	// place a new button as the first element of some div
			//	|	var button = new Button({ label:"click" }).placeAt("wrapper","first");
			// example:
			//	|	// create a contentpane and add it to a TabContainer
			//	|	var tc = dijit.byId("myTabs");
			//	|	new ContentPane({ href:"foo.html", title:"Wow!" }).placeAt(tc)

			var refWidget = !reference.tagName && registry.byId(reference);
			if(refWidget && refWidget.addChild && (!position || typeof position === "number")){
				// Adding this to refWidget and can use refWidget.addChild() to handle everything.
				refWidget.addChild(this, position);
			}else{
				// "reference" is a plain DOMNode, or we can't use refWidget.addChild().   Use domConstruct.place() and
				// target refWidget.containerNode for nested placement (position==number, "first", "last", "only"), and
				// refWidget.domNode otherwise ("after"/"before"/"replace").  (But not supported officially, see #14946.)
				var ref = refWidget && ("domNode" in refWidget) ?
					(refWidget.containerNode && !/after|before|replace/.test(position || "") ?
						refWidget.containerNode : refWidget.domNode) : dom.byId(reference, this.ownerDocument);
				domConstruct.place(this.domNode, ref, position);

				// Start this iff it has a parent widget that's already started.
				// TODO: for 2.0 maybe it should also start the widget when this.getParent() returns null??
				if(!this._started && (this.getParent() || {})._started){
					this.startup();
				}
			}
			return this;
		},

		defer: function(fcn, delay){
			// summary:
			//		Wrapper to setTimeout to avoid deferred functions executing
			//		after the originating widget has been destroyed.
			//		Returns an object handle with a remove method (that returns null) (replaces clearTimeout).
			// fcn: Function
			//		Function reference.
			// delay: Number?
			//		Delay, defaults to 0.
			// tags:
			//		protected

			var timer = setTimeout(lang.hitch(this,
				function(){
					if(!timer){
						return;
					}
					timer = null;
					if(!this._destroyed){
						lang.hitch(this, fcn)();
					}
				}),
				delay || 0
			);
			return {
				remove: function(){
					if(timer){
						clearTimeout(timer);
						timer = null;
					}
					return null; // so this works well: handle = handle.remove();
				}
			};
		}
	});

	if(has("dojo-bidi")){
		_WidgetBase.extend(_BidiMixin);
	}

	return _WidgetBase;
});