widget.js

dojo与json创建无限级树的时候,当在父结点下添加了一个新结点,我怎么让父亲结点重新调用json加载一下子结点内容.

/*
	Copyright (c) 2004-2006, The Dojo Foundation
	All Rights Reserved.

	Licensed under the Academic Free License version 2.1 or above OR the
	modified BSD license. For more information on Dojo licensing, see:

		http://dojotoolkit.org/community/licensing.shtml
*/

dojo.provide("dojo.widget.Widget");
dojo.provide("dojo.widget.tags");

dojo.require("dojo.lang.func");
dojo.require("dojo.lang.array");
dojo.require("dojo.lang.extras");
dojo.require("dojo.lang.declare");
dojo.require("dojo.widget.Manager");
dojo.require("dojo.event.*");

dojo.declare("dojo.widget.Widget", null, {
	initializer: function() {								 
		// these properties aren't primitives and need to be created on a per-item
		// basis.
		this.children = [];
		// this.selection = new dojo.widget.Selection();
		// FIXME: need to replace this with context menu stuff
		this.extraArgs = {};
	},
	// FIXME: need to be able to disambiguate what our rendering context is
	//        here!
	//
	// needs to be a string with the end classname. Every subclass MUST
	// over-ride.
	//
	// base widget properties
	parent: null,
	// obviously, top-level and modal widgets should set these appropriately
	isTopLevel:  false,
	isModal: false,

	isEnabled: true,
	isHidden: false,
	isContainer: false, // can we contain other widgets?
	widgetId: "",
	widgetType: "Widget", // used for building generic widgets

	toString: function() {
		return '[Widget ' + this.widgetType + ', ' + (this.widgetId || 'NO ID') + ']';
	},

	repr: function(){
		return this.toString();
	},

	enable: function(){
		// should be over-ridden
		this.isEnabled = true;
	},

	disable: function(){
		// should be over-ridden
		this.isEnabled = false;
	},

	hide: function(){
		// should be over-ridden
		this.isHidden = true;
	},

	show: function(){
		// should be over-ridden
		this.isHidden = false;
	},

	onResized: function(){
		// Clients should override this function to do special processing,
		// then call this.notifyChildrenOfResize() to notify children of resize
		this.notifyChildrenOfResize();
	},
	
	notifyChildrenOfResize: function(){
		for(var i=0; i<this.children.length; i++){
			var child = this.children[i];
			//dojo.debug(this.widgetId + " resizing child " + child.widgetId);
			if( child.onResized ){
				child.onResized();
			}
		}
	},

	create: function(args, fragment, parentComp){
		// dojo.debug(this.widgetType, "create");
		this.satisfyPropertySets(args, fragment, parentComp);
		// dojo.debug(this.widgetType, "-> mixInProperties");
		this.mixInProperties(args, fragment, parentComp);
		// dojo.debug(this.widgetType, "-> postMixInProperties");
		this.postMixInProperties(args, fragment, parentComp);
		// dojo.debug(this.widgetType, "-> dojo.widget.manager.add");
		dojo.widget.manager.add(this);
		// dojo.debug(this.widgetType, "-> buildRendering");
		this.buildRendering(args, fragment, parentComp);
		// dojo.debug(this.widgetType, "-> initialize");
		this.initialize(args, fragment, parentComp);
		// dojo.debug(this.widgetType, "-> postInitialize");
		this.postInitialize(args, fragment, parentComp);
		// dojo.debug(this.widgetType, "-> postCreate");
		this.postCreate(args, fragment, parentComp);
		// dojo.debug(this.widgetType, "done!");
		return this;
	},

	// Destroy this widget and it's descendants
	destroy: function(finalize){
		// FIXME: this is woefully incomplete
		this.destroyChildren();
		this.uninitialize();
		this.destroyRendering(finalize);
		dojo.widget.manager.removeById(this.widgetId);
	},

	// Destroy the children of this widget, and their descendents
	destroyChildren: function(){
		while(this.children.length > 0){
			var tc = this.children[0];
			this.removeChild(tc);
			tc.destroy();
		}
	},

	getChildrenOfType: function(type, recurse){
		var ret = [];
		var isFunc = dojo.lang.isFunction(type);
		if(!isFunc){
			type = type.toLowerCase();
		}
		for(var x=0; x<this.children.length; x++){
			if(isFunc){
				if(this.children[x] instanceof type){
					ret.push(this.children[x]);
				}
			}else{
				if(this.children[x].widgetType.toLowerCase() == type){
					ret.push(this.children[x]);
				}
			}
			if(recurse){
				ret = ret.concat(this.children[x].getChildrenOfType(type, recurse));
			}
		}
		return ret;
	},

	getDescendants: function(){
		var result = [];
		var stack = [this];
		var elem;
		while (elem = stack.pop()){
			result.push(elem);
			dojo.lang.forEach(elem.children, function(elem) { stack.push(elem); });
		}
		return result;
	},

	satisfyPropertySets: function(args){
		// dojo.profile.start("satisfyPropertySets");
		// get the default propsets for our component type
		/*
		var typePropSets = []; // FIXME: need to pull these from somewhere!
		var localPropSets = []; // pull out propsets from the parser's return structure

		// for(var x=0; x<args.length; x++){
		// }

		for(var x=0; x<typePropSets.length; x++){
		}

		for(var x=0; x<localPropSets.length; x++){
		}
		*/
		// dojo.profile.end("satisfyPropertySets");
		
		return args;
	},

	mixInProperties: function(args, frag){
		if((args["fastMixIn"])||(frag["fastMixIn"])){
			// dojo.profile.start("mixInProperties_fastMixIn");
			// fast mix in assumes case sensitivity, no type casting, etc...
			// dojo.lang.mixin(this, args);
			for(var x in args){
				this[x] = args[x];
			}
			// dojo.profile.end("mixInProperties_fastMixIn");
			return;
		}
		// dojo.profile.start("mixInProperties");
		/*
		 * the actual mix-in code attempts to do some type-assignment based on
		 * PRE-EXISTING properties of the "this" object. When a named property
		 * of a propset is located, it is first tested to make sure that the
		 * current object already "has one". Properties which are undefined in
		 * the base widget are NOT settable here. The next step is to try to
		 * determine type of the pre-existing property. If it's a string, the
		 * property value is simply assigned. If a function, the property is
		 * replaced with a "new Function()" declaration. If an Array, the
		 * system attempts to split the string value on ";" chars, and no
		 * further processing is attempted (conversion of array elements to a
		 * integers, for instance). If the property value is an Object
		 * (testObj.constructor === Object), the property is split first on ";"
		 * chars, secondly on ":" chars, and the resulting key/value pairs are
		 * assigned to an object in a map style. The onus is on the property
		 * user to ensure that all property values are converted to the
		 * expected type before usage.
		 */

		var undef;

		// NOTE: we cannot assume that the passed properties are case-correct
		// (esp due to some browser bugs). Therefore, we attempt to locate
		// properties for assignment regardless of case. This may cause
		// problematic assignments and bugs in the future and will need to be
		// documented with big bright neon lights.

		// FIXME: fails miserably if a mixin property has a default value of null in 
		// a widget

		// NOTE: caching lower-cased args in the prototype is only 
		// acceptable if the properties are invariant.
		// if we have a name-cache, get it
		var lcArgs = dojo.widget.lcArgsCache[this.widgetType];
		if ( lcArgs == null ){
			// build a lower-case property name cache if we don't have one
			lcArgs = {};
			for(var y in this){
				lcArgs[((new String(y)).toLowerCase())] = y;
			}
			dojo.widget.lcArgsCache[this.widgetType] = lcArgs;
		}
		var visited = {};
		for(var x in args){
			if(!this[x]){ // check the cache for properties
				var y = lcArgs[(new String(x)).toLowerCase()];
				if(y){
					args[y] = args[x];
					x = y; 
				}
			}
			if(visited[x]){ continue; }
			visited[x] = true;
			if((typeof this[x]) != (typeof undef)){
				if(typeof args[x] != "string"){
					this[x] = args[x];
				}else{
					if(dojo.lang.isString(this[x])){
						this[x] = args[x];
					}else if(dojo.lang.isNumber(this[x])){
						this[x] = new Number(args[x]); // FIXME: what if NaN is the result?
					}else if(dojo.lang.isBoolean(this[x])){
						this[x] = (args[x].toLowerCase()=="false") ? false : true;
					}else if(dojo.lang.isFunction(this[x])){

						// FIXME: need to determine if always over-writing instead
						// of attaching here is appropriate. I suspect that we
						// might want to only allow attaching w/ action items.
						
						// RAR, 1/19/05: I'm going to attach instead of
						// over-write here. Perhaps function objects could have
						// some sort of flag set on them? Or mixed-into objects
						// could have some list of non-mutable properties
						// (although I'm not sure how that would alleviate this
						// particular problem)? 

						// this[x] = new Function(args[x]);

						// after an IRC discussion last week, it was decided
						// that these event handlers should execute in the
						// context of the widget, so that the "this" pointer
						// takes correctly.
						
						// argument that contains no punctuation other than . is 
						// considered a function spec, not code
						if(args[x].search(/[^\w\.]+/i) == -1){
							this[x] = dojo.evalObjPath(args[x], false);
						}else{
							var tn = dojo.lang.nameAnonFunc(new Function(args[x]), this);
							dojo.event.connect(this, x, this, tn);
						}