xhr.js

这是一个ajax的例子大家好好的看看就是一个鱼眼的效果

if(!dojo._hasResource["dojo._base.xhr"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo._base.xhr"] = true;
dojo.provide("dojo._base.xhr");
dojo.require("dojo._base.Deferred");
dojo.require("dojo._base.json");
dojo.require("dojo._base.lang");
dojo.require("dojo._base.query");

(function(){
	var _d = dojo;
	function setValue(/*Object*/obj, /*String*/name, /*String*/value){
		//summary:
		//		For the nameed property in object, set the value. If a value
		//		already exists and it is a string, convert the value to be an
		//		array of values.
		var val = obj[name];
		if(_d.isString(val)){
			obj[name] = [val, value];
		}else if(_d.isArray(val)){
			val.push(value);
		}else{
			obj[name] = value;
		}
	}

	dojo.formToObject = function(/*DOMNode||String*/ formNode){
		// summary:
		//		dojo.formToObject returns the values encoded in an HTML form as
		//		string properties in an object which it then returns. Disabled form
		//		elements, buttons, and other non-value form elements are skipped.
		//		Multi-select elements are returned as an array of string values.
		// description:
		//		This form:
		//
		//		|	<form id="test_form">
		//		|		<input type="text" name="blah" value="blah">
		//		|		<input type="text" name="no_value" value="blah" disabled>
		//		|		<input type="button" name="no_value2" value="blah">
		//		|		<select type="select" multiple name="multi" size="5">
		//		|			<option value="blah">blah</option>
		//		|			<option value="thud" selected>thud</option>
		//		|			<option value="thonk" selected>thonk</option>
		//		|		</select>
		//		|	</form>
		//
		//		yields this object structure as the result of a call to
		//		formToObject():
		//
		//		|	{ 
		//		|		blah: "blah",
		//		|		multi: [
		//		|			"thud",
		//		|			"thonk"
		//		|		]
		//		|	};
	
		var ret = {};
		var iq = "input:not([type=file]):not([type=submit]):not([type=image]):not([type=reset]):not([type=button]), select, textarea";
		_d.query(iq, formNode).filter(function(node){
			return !node.disabled && node.name;
		}).forEach(function(item){
			var _in = item.name;
			var type = (item.type||"").toLowerCase();
			if(type == "radio" || type == "checkbox"){
				if(item.checked){ setValue(ret, _in, item.value); }
			}else if(item.multiple){
				ret[_in] = [];
				_d.query("option", item).forEach(function(opt){
					if(opt.selected){
						setValue(ret, _in, opt.value);
					}
				});
			}else{ 
				setValue(ret, _in, item.value);
				if(type == "image"){
					ret[_in+".x"] = ret[_in+".y"] = ret[_in].x = ret[_in].y = 0;
				}
			}
		});
		return ret; // Object
	}

	dojo.objectToQuery = function(/*Object*/ map){
		//	summary:
		//		takes a name/value mapping object and returns a string representing
		//		a URL-encoded version of that object.
		//	example:
		//		this object:
		//
		//		|	{ 
		//		|		blah: "blah",
		//		|		multi: [
		//		|			"thud",
		//		|			"thonk"
		//		|		]
		//		|	};
		//
		//	yields the following query string:
		//	
		//	|	"blah=blah&multi=thud&multi=thonk"

		// FIXME: need to implement encodeAscii!!
		var enc = encodeURIComponent;
		var pairs = [];
		var backstop = {};
		for(var name in map){
			var value = map[name];
			if(value != backstop[name]){
				var assign = enc(name) + "=";
				if(_d.isArray(value)){
					for(var i=0; i < value.length; i++){
						pairs.push(assign + enc(value[i]));
					}
				}else{
					pairs.push(assign + enc(value));
				}
			}
		}
		return pairs.join("&"); // String
	}

	dojo.formToQuery = function(/*DOMNode||String*/ formNode){
		// summary:
		//		Returns a URL-encoded string representing the form passed as either a
		//		node or string ID identifying the form to serialize
		return _d.objectToQuery(_d.formToObject(formNode)); // String
	}

	dojo.formToJson = function(/*DOMNode||String*/ formNode, /*Boolean?*/prettyPrint){
		// summary:
		//		return a serialized JSON string from a form node or string
		//		ID identifying the form to serialize
		return _d.toJson(_d.formToObject(formNode), prettyPrint); // String
	}

	dojo.queryToObject = function(/*String*/ str){
		// summary:
		//		returns an object representing a de-serialized query section of a
		//		URL. Query keys with multiple values are returned in an array.
		// description:
		//		This string:
		//
		//	|		"foo=bar&foo=baz&thinger=%20spaces%20=blah&zonk=blarg&"
		//		
		//		results in this object structure:
		//
		//	|		{
		//	|			foo: [ "bar", "baz" ],
		//	|			thinger: " spaces =blah",
		//	|			zonk: "blarg"
		//	|		}
		//	
		//		Note that spaces and other urlencoded entities are correctly
		//		handled.

		// FIXME: should we grab the URL string if we're not passed one?
		var ret = {};
		var qp = str.split("&");
		var dec = decodeURIComponent;
		_d.forEach(qp, function(item){
			if(item.length){
				var parts = item.split("=");
				var name = dec(parts.shift());
				var val = dec(parts.join("="));
				if(_d.isString(ret[name])){
					ret[name] = [ret[name]];
				}
				if(_d.isArray(ret[name])){
					ret[name].push(val);
				}else{
					ret[name] = val;
				}
			}
		});
		return ret; // Object
	}

	/*
		from refactor.txt:

		all bind() replacement APIs take the following argument structure:

			{
				url: "blah.html",

				// all below are optional, but must be supported in some form by
				// every IO API
				timeout: 1000, // milliseconds
				handleAs: "text", // replaces the always-wrong "mimetype"
				content: { 
					key: "value"
				},

				// browser-specific, MAY be unsupported
				sync: true, // defaults to false
				form: dojo.byId("someForm") 
			}
	*/

	// need to block async callbacks from snatching this thread as the result
	// of an async callback might call another sync XHR, this hangs khtml forever
	// must checked by watchInFlight()

	dojo._blockAsync = false;

	dojo._contentHandlers = {
		"text": function(xhr){ return xhr.responseText; },
		"json": function(xhr){
			if(!dojo.config.usePlainJson){
				console.warn("Consider using mimetype:text/json-comment-filtered"
					+ " to avoid potential security issues with JSON endpoints"
					+ " (use djConfig.usePlainJson=true to turn off this message)");
			}
			return (xhr.status == 204) ? undefined : _d.fromJson(xhr.responseText);
		},
		"json-comment-filtered": function(xhr){ 
			// NOTE: we provide the json-comment-filtered option as one solution to
			// the "JavaScript Hijacking" issue noted by Fortify and others. It is
			// not appropriate for all circumstances.

			var value = xhr.responseText;
			var cStartIdx = value.indexOf("\/*");
			var cEndIdx = value.lastIndexOf("*\/");
			if(cStartIdx == -1 || cEndIdx == -1){
				throw new Error("JSON was not comment filtered");
			}
			return (xhr.status == 204) ? undefined :
				_d.fromJson(value.substring(cStartIdx+2, cEndIdx));
		},
		"javascript": function(xhr){ 
			// FIXME: try Moz and IE specific eval variants?
			return _d.eval(xhr.responseText);
		},
		"xml": function(xhr){ 
			var result = xhr.responseXML;
			if(_d.isIE && (!result || window.location.protocol == "file:")){
				_d.forEach(["MSXML2", "Microsoft", "MSXML", "MSXML3"], function(prefix){
					try{
						var dom = new ActiveXObject(prefix + ".XMLDOM");
						dom.async = false;
						dom.loadXML(xhr.responseText);
						result = dom;
					}catch(e){ /* Not available. Squelch and try next one. */ }
				});
			}
			return result; // DOMDocument
		}
	};

	dojo._contentHandlers["json-comment-optional"] = function(xhr){
		var handlers = _d._contentHandlers;
		try{
			return handlers["json-comment-filtered"](xhr);
		}catch(e){
			return handlers["json"](xhr);
		}
	};

	/*=====
	dojo.__IoArgs = function(){
		//	url: String
		//		URL to server endpoint.
		//	content: Object?
		//		Contains properties with string values. These
		//		properties will be serialized as name1=value2 and
		//		passed in the request.
		//	timeout: Integer?
		//		Milliseconds to wait for the response. If this time
		//		passes, the then error callbacks are called.
		//	form: DOMNode?
		//		DOM node for a form. Used to extract the form values
		//		and send to the server.
		//	preventCache: Boolean?
		//		Default is false. If true, then a
		//		"dojo.preventCache" parameter is sent in the request
		//		with a value that changes with each request
		//		(timestamp). Useful only with GET-type requests.
		//	handleAs: String?
		//		Acceptable values depend on the type of IO
		//		transport (see specific IO calls for more information).
		//	load: Function?
		//		function(response, ioArgs){}. response is an Object, ioArgs
		//		is of type dojo.__IoCallbackArgs. The load function will be
		//		called on a successful response.
		//	error: Function?
		//		function(response, ioArgs){}. response is an Object, ioArgs
		//		is of type dojo.__IoCallbackArgs. The error function will
		//		be called in an error case. 
		//	handle: Function?
		//		function(response, ioArgs){}. response is an Object, ioArgs
		//		is of type dojo.__IoCallbackArgs. The handle function will
		//		be called in either the successful or error case.  For
		//		the load, error and handle functions, the ioArgs object
		//		will contain the following properties: 
		this.url = url;
		this.content = content;
		this.timeout = timeout;
		this.form = form;
		this.preventCache = preventCache;
		this.handleAs = handleAs;
		this.load = load;
		this.error = error;
		this.handle = handle;
	}
	=====*/

	/*=====
	dojo.__IoCallbackArgs = function(args, xhr, url, query, handleAs, id, canDelete, json){
		//	args: Object
		//		the original object argument to the IO call.
		//	xhr: XMLHttpRequest
		//		For XMLHttpRequest calls only, the
		//		XMLHttpRequest object that was used for the
		//		request.
		//	url: String
		//		The final URL used for the call. Many times it
		//		will be different than the original args.url
		//		value.
		//	query: String
		//		For non-GET requests, the
		//		name1=value1&name2=value2 parameters sent up in
		//		the request.
		//	handleAs: String
		//		The final indicator on how the response will be
		//		handled.
		//	id: String
		//		For dojo.io.script calls only, the internal
		//		script ID used for the request.
		//	canDelete: Boolean
		//		For dojo.io.script calls only, indicates
		//		whether the script tag that represents the
		//		request can be deleted after callbacks have
		//		been called. Used internally to know when
		//		cleanup can happen on JSONP-type requests.
		//	json: Object
		//		For dojo.io.script calls only: holds the JSON
		//		response for JSONP-type requests. Used
		//		internally to hold on to the JSON responses.
		//		You should not need to access it directly --
		//		the same object should be passed to the success
		//		callbacks directly.
		this.args = args;
		this.xhr = xhr;
		this.url = url;
		this.query = query;
		this.handleAs = handleAs;
		this.id = id;
		this.canDelete = canDelete;
		this.json = json;
	}
	=====*/



	dojo._ioSetArgs = function(/*dojo.__IoArgs*/args,
			/*Function*/canceller,
			/*Function*/okHandler,
			/*Function*/errHandler){
		//	summary: 
		//		sets up the Deferred and ioArgs property on the Deferred so it
		//		can be used in an io call.
		//	args:
		//		The args object passed into the public io call. Recognized properties on
		//		the args object are:
		//	canceller:
		//		The canceller function used for the Deferred object. The function