hostenv_browser.js

对java中如何使用Ajax技术

	function dj_addNodeEvtHdlr(/*DomNode*/node, /*String*/evtName, /*Function*/fp){
		// summary:
		//		non-destructively adds the specified function to the node's
		//		evtName handler.
		// node: the DomNode to add the handler to
		// evtName: should be in the form "click" for "onclick" handlers
		var oldHandler = node["on"+evtName] || function(){};
		node["on"+evtName] = function(){
			fp.apply(node, arguments);
			oldHandler.apply(node, arguments);
		}
		return true;
	}

	//	BEGIN DOMContentLoaded, from Dean Edwards (http://dean.edwards.name/weblog/2006/06/again/)
	function dj_load_init(e){
		// allow multiple calls, only first one will take effect
		// A bug in khtml calls events callbacks for document for event which isnt supported
		// for example a created contextmenu event calls DOMContentLoaded, workaround
		var type = (e && e.type) ? e.type.toLowerCase() : "load";
		if(arguments.callee.initialized || (type!="domcontentloaded" && type!="load")){ return; }
		arguments.callee.initialized = true;
		if(typeof(_timer) != 'undefined'){
			clearInterval(_timer);
			delete _timer;
		}

		var initFunc = function(){
			//perform initialization
			if(dojo.render.html.ie){
				dojo.hostenv.makeWidgets();
			}
		};

		if(dojo.hostenv.inFlightCount == 0){
			initFunc();
			dojo.hostenv.modulesLoaded();
		}else{
			//This else case should be xdomain loading.
			//Make sure this is the first thing in the load listener array.
			//Part of the dojo.addOnLoad guarantee is that when the listeners are notified,
			//It means the DOM (or page) has loaded and that widgets have been parsed.
			dojo.hostenv.modulesLoadedListeners.unshift(initFunc);
		}
	}

	//	START DOMContentLoaded
	// Mozilla and Opera 9 expose the event we could use
	if(document.addEventListener){
		if(dojo.render.html.opera || (dojo.render.html.moz && !djConfig.delayMozLoadingFix)){
			document.addEventListener("DOMContentLoaded", dj_load_init, null);
		}

		//	mainly for Opera 8.5, won't be fired if DOMContentLoaded fired already.
		//  also used for Mozilla because of trac #1640
		window.addEventListener("load", dj_load_init, null);
	}

	// 	for Internet Explorer. readyState will not be achieved on init call, but dojo doesn't need it
	//	however, we'll include it because we don't know if there are other functions added that might.
	//	Note that this has changed because the build process strips all comments--including conditional
	//		ones.
	if(dojo.render.html.ie && dojo.render.os.win){
		document.attachEvent("onreadystatechange", function(e){
			if(document.readyState == "complete"){
				dj_load_init();
			}
		});
	}

	if (/(WebKit|khtml)/i.test(navigator.userAgent)) { // sniff
		var _timer = setInterval(function() {
			if (/loaded|complete/.test(document.readyState)) {
				dj_load_init(); // call the onload handler
			}
		}, 10);
	}
	//	END DOMContentLoaded

	// IE WebControl hosted in an application can fire "beforeunload" and "unload"
	// events when control visibility changes, causing Dojo to unload too soon. The
	// following code fixes the problem
	// Reference: http://support.microsoft.com/default.aspx?scid=kb;en-us;199155
	if(dojo.render.html.ie){
		dj_addNodeEvtHdlr(window, "beforeunload", function(){
			dojo.hostenv._unloading = true;
			window.setTimeout(function() {
				dojo.hostenv._unloading = false;
			}, 0);
		});
	}

	dj_addNodeEvtHdlr(window, "unload", function(){
		dojo.hostenv.unloaded();
		if((!dojo.render.html.ie)||(dojo.render.html.ie && dojo.hostenv._unloading)){
			dojo.hostenv.unloaded();
		}
	});

	dojo.hostenv.makeWidgets = function(){
		// you can put searchIds in djConfig and dojo.hostenv at the moment
		// we should probably eventually move to one or the other
		var sids = [];
		if(djConfig.searchIds && djConfig.searchIds.length > 0) {
			sids = sids.concat(djConfig.searchIds);
		}
		if(dojo.hostenv.searchIds && dojo.hostenv.searchIds.length > 0) {
			sids = sids.concat(dojo.hostenv.searchIds);
		}

		if((djConfig.parseWidgets)||(sids.length > 0)){
			if(dojo.evalObjPath("dojo.widget.Parse")){
				// we must do this on a delay to avoid:
				//	http://www.shaftek.org/blog/archives/000212.html
				// (IE bug)
					var parser = new dojo.xml.Parse();
					if(sids.length > 0){
						for(var x=0; x<sids.length; x++){
							var tmpNode = document.getElementById(sids[x]);
							if(!tmpNode){ continue; }
							var frag = parser.parseElement(tmpNode, null, true);
							dojo.widget.getParser().createComponents(frag);
						}
					}else if(djConfig.parseWidgets){
						var frag  = parser.parseElement(dojo.body(), null, true);
						dojo.widget.getParser().createComponents(frag);
					}
			}
		}
	}

	dojo.addOnLoad(function(){
		if(!dojo.render.html.ie) {
			dojo.hostenv.makeWidgets();
		}
	});

	try{
		if(dojo.render.html.ie){
			document.namespaces.add("v","urn:schemas-microsoft-com:vml");
			document.createStyleSheet().addRule("v\\:*", "behavior:url(#default#VML)");
		}
	}catch(e){ }

	// stub, over-ridden by debugging code. This will at least keep us from
	// breaking when it's not included
	dojo.hostenv.writeIncludes = function(){}

	//TODOC:  HOW TO DOC THIS?
	// @global: dj_currentDocument
	// summary:
	//		Current document object. 'dj_currentDocument' can be modified for temporary context shifting.
	// description:
	//    dojo.doc() returns dojo.currentDocument.
	//		Refer to dojo.doc() rather than referring to 'window.document' to ensure your
	//		code runs correctly in managed contexts.
	if(!dj_undef("document", this)){
		dj_currentDocument = this.document;
	}

	dojo.doc = function(){
		// summary:
		//		return the document object associated with the dojo.global()
		return dj_currentDocument;
	}

	dojo.body = function(){
		// summary:
		//		return the body object associated with dojo.doc()
		// Note: document.body is not defined for a strict xhtml document
		return dojo.doc().body || dojo.doc().getElementsByTagName("body")[0];
	}

	dojo.byId = function(/*String*/id, /*DocumentElement*/doc){
		// summary:
		// 		similar to other library's "$" function, takes a string
		// 		representing a DOM id or a DomNode and returns the
		// 		corresponding DomNode. If a Node is passed, this function is a
		// 		no-op. Returns a single DOM node or null, working around
		// 		several browser-specific bugs to do so.
		// id: DOM id or DOM Node
		// doc:
		//		optional, defaults to the current value of dj_currentDocument.
		//		Can be used to retreive node references from other documents.
		if((id)&&((typeof id == "string")||(id instanceof String))){
			if(!doc){ doc = dj_currentDocument; }
			var ele = doc.getElementById(id);
			// workaround bug in IE and Opera 8.2 where getElementById returns wrong element
			if(ele && (ele.id != id) && doc.all){
				ele = null;
				// get all matching elements with this id
				eles = doc.all[id];
				if(eles){
					// if more than 1, choose first with the correct id
					if(eles.length){
						for(var i=0; i<eles.length; i++){
							if(eles[i].id == id){
								ele = eles[i];
								break;
							}
						}
					// return 1 and only element
					}else{
						ele = eles;
					}
				}
			}
			return ele; // DomNode
		}
		return id; // DomNode
	}

	dojo.setContext = function(/*Object*/globalObject, /*DocumentElement*/globalDocument){
		// summary:
		//		changes the behavior of many core Dojo functions that deal with
		//		namespace and DOM lookup, changing them to work in a new global
		//		context. The varibles dj_currentContext and dj_currentDocument
		//		are modified as a result of calling this function.
		dj_currentContext = globalObject;
		dj_currentDocument = globalDocument;
	};

	dojo._fireCallback = function(callback, context, cbArguments){
		if((context)&&((typeof callback == "string")||(callback instanceof String))){
			callback=context[callback];
		}
		return (context ? callback.apply(context, cbArguments || [ ]) : callback());
	}

	dojo.withGlobal = function(/*Object*/globalObject, /*Function*/callback, /*Object?*/thisObject, /*Array?*/cbArguments){
		// summary:
		//		Call callback with globalObject as dojo.global() and globalObject.document
		//		as dojo.doc(). If provided, globalObject will be executed in the context of
		//		object thisObject
		// description:
		//		When callback() returns or throws an error, the dojo.global() and dojo.doc() will
		//		be restored to its previous state.
		var rval;
		var oldGlob = dj_currentContext;
		var oldDoc = dj_currentDocument;
		try{
			dojo.setContext(globalObject, globalObject.document);
			rval = dojo._fireCallback(callback, thisObject, cbArguments);
		}finally{
			dojo.setContext(oldGlob, oldDoc);
		}
		return rval;
	}

	dojo.withDoc = function (/*Object*/documentObject, /*Function*/callback, /*Object?*/thisObject, /*Array?*/cbArguments) {
		// summary:
		//		Call callback with documentObject as dojo.doc(). If provided, callback will be executed
		//		in the context of object thisObject
		// description:
		//		When callback() returns or throws an error, the dojo.doc() will
		//		be restored to its previous state.
		var rval;
		var oldDoc = dj_currentDocument;
		try{
			dj_currentDocument = documentObject;
			rval = dojo._fireCallback(callback, thisObject, cbArguments);
		}finally{
			dj_currentDocument = oldDoc;
		}
		return rval;
	}

} //if (typeof window != 'undefined')