domwidget.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.

	templateNode: null,
	templateString: null,
	templateCssString: null,
	preventClobber: false,
	domNode: null, // this is our visible representation of the widget!
	containerNode: null, // holds child elements

	// Process the given child widget, inserting it's dom node as a child of our dom node
	// FIXME: should we support addition at an index in the children arr and
	// order the display accordingly? Right now we always append.
	addChild: function(widget, overrideContainerNode, pos, ref, insertIndex){
		if(!this.isContainer){ // we aren't allowed to contain other widgets, it seems
			dojo.debug("dojo.widget.DomWidget.addChild() attempted on non-container widget");
			return null;
		}else{
			this.addWidgetAsDirectChild(widget, overrideContainerNode, pos, ref, insertIndex);
			this.registerChild(widget, insertIndex);
		}
		return widget;
	},
	
	addWidgetAsDirectChild: function(widget, overrideContainerNode, pos, ref, insertIndex){
		if((!this.containerNode)&&(!overrideContainerNode)){
			this.containerNode = this.domNode;
		}
		var cn = (overrideContainerNode) ? overrideContainerNode : this.containerNode;
		if(!pos){ pos = "after"; }
		if(!ref){ 
			// if(!cn){ cn = document.body; }
			if(!cn){ cn = document.body; }
			ref = cn.lastChild; 
		}
		if(!insertIndex) { insertIndex = 0; }
		widget.domNode.setAttribute("dojoinsertionindex", insertIndex);

		// insert the child widget domNode directly underneath my domNode, in the
		// specified position (by default, append to end)
		if(!ref){
			cn.appendChild(widget.domNode);
		}else{
			// FIXME: was this meant to be the (ugly hack) way to support insert @ index?
			//dojo.dom[pos](widget.domNode, ref, insertIndex);

			// CAL: this appears to be the intended way to insert a node at a given position...
			if (pos == 'insertAtIndex'){
				// dojo.debug("idx:", insertIndex, "isLast:", ref === cn.lastChild);
				dojo.dom.insertAtIndex(widget.domNode, ref.parentNode, insertIndex);
			}else{
				// dojo.debug("pos:", pos, "isLast:", ref === cn.lastChild);
				if((pos == "after")&&(ref === cn.lastChild)){
					cn.appendChild(widget.domNode);
				}else{
					dojo.dom.insertAtPosition(widget.domNode, cn, pos);
				}
			}
		}
	},

	// Record that given widget descends from me
	registerChild: function(widget, insertionIndex){

		// we need to insert the child at the right point in the parent's 
		// 'children' array, based on the insertionIndex

		widget.dojoInsertionIndex = insertionIndex;

		var idx = -1;
		for(var i=0; i<this.children.length; i++){
			if (this.children[i].dojoInsertionIndex < insertionIndex){
				idx = i;
			}
		}

		this.children.splice(idx+1, 0, widget);

		widget.parent = this;
		widget.addedTo(this);
		
		// If this widget was created programatically, then it was erroneously added
		// to dojo.widget.manager.topWidgets.  Fix that here.
		delete dojo.widget.manager.topWidgets[widget.widgetId];
	},

	removeChild: function(widget){
		// detach child domNode from parent domNode
		dojo.dom.removeNode(widget.domNode);

		// remove child widget from parent widget
		return dojo.widget.DomWidget.superclass.removeChild.call(this, widget);
	},

	getFragNodeRef: function(frag){
		if( !frag || !frag["dojo:"+this.widgetType.toLowerCase()] ){
			dojo.raise("Error: no frag for widget type " + this.widgetType +
				", id " + this.widgetId + " (maybe a widget has set it's type incorrectly)");
		}
		return (frag ? frag["dojo:"+this.widgetType.toLowerCase()]["nodeRef"] : null);
	},
	
	// Replace source domNode with generated dom structure, and register
	// widget with parent.
	postInitialize: function(args, frag, parentComp){
		var sourceNodeRef = this.getFragNodeRef(frag);
		// Stick my generated dom into the output tree
		//alert(this.widgetId + ": replacing " + sourceNodeRef + " with " + this.domNode.innerHTML);
		if (parentComp && (parentComp.snarfChildDomOutput || !sourceNodeRef)){
			// Add my generated dom as a direct child of my parent widget
			// This is important for generated widgets, and also cases where I am generating an
			// <li> node that can't be inserted back into the original DOM tree
			parentComp.addWidgetAsDirectChild(this, "", "insertAtIndex", "",  args["dojoinsertionindex"], sourceNodeRef);
		} else if (sourceNodeRef){
			// Do in-place replacement of the my source node with my generated dom
			if(this.domNode && (this.domNode !== sourceNodeRef)){
				var oldNode = sourceNodeRef.parentNode.replaceChild(this.domNode, sourceNodeRef);
			}
		}

		// Register myself with my parent, or with the widget manager if
		// I have no parent
		// TODO: the code below erroneously adds all programatically generated widgets
		// to topWidgets (since we don't know who the parent is until after creation finishes)
		if ( parentComp ) {
			parentComp.registerChild(this, args.dojoinsertionindex);
		} else {
			dojo.widget.manager.topWidgets[this.widgetId]=this;
		}

		// Expand my children widgets
		if(this.isContainer){
			//alert("recurse from " + this.widgetId);
			// build any sub-components with us as the parent
			var fragParser = dojo.widget.getParser();
			fragParser.createSubComponents(frag, this);
		}
	},

	// method over-ride
	buildRendering: function(args, frag){
		// DOM widgets construct themselves from a template
		var ts = dojo.widget._templateCache[this.widgetType];
		if(	
			(!this.preventClobber)&&(
				(this.templatePath)||
				(this.templateNode)||
				(
					(this["templateString"])&&(this.templateString.length) 
				)||
				(
					(typeof ts != "undefined")&&( (ts["string"])||(ts["node"]) )
				)
			)
		){
			// if it looks like we can build the thing from a template, do it!
			this.buildFromTemplate(args, frag);
		}else{
			// otherwise, assign the DOM node that was the source of the widget
			// parsing to be the root node
			this.domNode = this.getFragNodeRef(frag);
		}
		this.fillInTemplate(args, frag); 	// this is where individual widgets
											// will handle population of data
											// from properties, remote data
											// sets, etc.
	},

	buildFromTemplate: function(args, frag){
		// var start = new Date();
		// copy template properties if they're already set in the templates object
		// dojo.debug("buildFromTemplate:", this);
		var avoidCache = false;
		if(args["templatecsspath"]){
			args["templateCssPath"] = args["templatecsspath"];
		}
		if(args["templatepath"]){
			avoidCache = true;
			args["templatePath"] = args["templatepath"];
		}
		dojo.widget.fillFromTemplateCache(	this, 
											args["templatePath"], 
											args["templateCssPath"],
											null,
											avoidCache);
		var ts = dojo.widget._templateCache[this.widgetType];
		if((ts)&&(!avoidCache)){
			if(!this.templateString.length){
				this.templateString = ts["string"];
			}
			if(!this.templateNode){
				this.templateNode = ts["node"];
			}
		}
		var matches = false;
		var node = null;
		// var tstr = new String(this.templateString); 
		var tstr = this.templateString; 
		// attempt to clone a template node, if there is one
		if((!this.templateNode)&&(this.templateString)){
			matches = this.templateString.match(/\$\{([^\}]+)\}/g);
			if(matches) {
				// if we do property replacement, don't create a templateNode
				// to clone from.
				var hash = this.strings || {};
				// FIXME: should this hash of default replacements be cached in
				// templateString?
				for(var key in dojo.widget.defaultStrings) {
					if(dojo.lang.isUndefined(hash[key])) {
						hash[key] = dojo.widget.defaultStrings[key];
					}
				}
				// FIXME: this is a lot of string munging. Can we make it faster?
				for(var i = 0; i < matches.length; i++) {
					var key = matches[i];
					key = key.substring(2, key.length-1);
					var kval = (key.substring(0, 5) == "this.") ? dojo.lang.getObjPathValue(key.substring(5), this) : hash[key];
					var value;
					if((kval)||(dojo.lang.isString(kval))){
						value = (dojo.lang.isFunction(kval)) ? kval.call(this, key, this.templateString) : kval;
						tstr = tstr.replace(matches[i], value);
					}
				}
			}else{
				// otherwise, we are required to instantiate a copy of the template
				// string if one is provided.
				
				// FIXME: need to be able to distinguish here what should be done
				// or provide a generic interface across all DOM implementations
				// FIMXE: this breaks if the template has whitespace as its first 
				// characters
				// node = this.createNodesFromText(this.templateString, true);
				// this.templateNode = node[0].cloneNode(true); // we're optimistic here
				this.templateNode = this.createNodesFromText(this.templateString, true)[0];
				if(!avoidCache){
					ts.node = this.templateNode;
				}
			}
		}
		if((!this.templateNode)&&(!matches)){ 
			dojo.debug("weren't able to create template!");
			return false;
		}else if(!matches){
			node = this.templateNode.cloneNode(true);
			if(!node){ return false; }
		}else{
			node = this.createNodesFromText(tstr, true)[0];
		}

		// recurse through the node, looking for, and attaching to, our
		// attachment points which should be defined on the template node.

		this.domNode = node;
		// dojo.profile.start("attachTemplateNodes");
		this.attachTemplateNodes(this.domNode, this);
		// dojo.profile.end("attachTemplateNodes");
		
		// relocate source contents to templated container node
		// this.containerNode must be able to receive children, or exceptions will be thrown
		if (this.isContainer && this.containerNode){
			var src = this.getFragNodeRef(frag);
			if (src){
				dojo.dom.moveChildren(src, this.containerNode);
			}
		}
	},

	attachTemplateNodes: function(baseNode, targetObj){
		if(!targetObj){ targetObj = this; }
		return dojo.widget.attachTemplateNodes(baseNode, targetObj, 
					dojo.widget.getDojoEventsFromStr(this.templateString));
	},

	fillInTemplate: function(){
		// dojo.unimplemented("dojo.widget.DomWidget.fillInTemplate");
	},
	
	// method over-ride
	destroyRendering: function(){
		try{
			delete this.domNode;
		}catch(e){ /* squelch! */ }
	},

	// FIXME: method over-ride
	cleanUp: function(){},
	
	getContainerHeight: function(){
		dojo.unimplemented("dojo.widget.DomWidget.getContainerHeight");
	},

	getContainerWidth: function(){
		dojo.unimplemented("dojo.widget.DomWidget.getContainerWidth");
	},

	createNodesFromText: function(){
		dojo.unimplemented("dojo.widget.DomWidget.createNodesFromText");
	}
});