connection.js

Ext JS是一个创建丰富互联网应用程序的跨浏览器的JavaScrip库。它包含：高效率

/*
 * Ext JS Library 3.0 Pre-alpha
 * Copyright(c) 2006-2008, Ext JS, LLC.
 * [e-mail]
 * 
 * http://extjs.com/license
 */

(function(){
	var BEFOREREQUEST = "beforerequest",
		REQUESTCOMPLETE = "requestcomplete",
		REQUESTEXCEPTION = "requestexception",
        UNDEFINED = undefined,
		LOAD = 'load',
		POST = 'POST',
		GET = 'GET',
		WINDOW = window;
	
	/**
	 * @class Ext.data.Connection
	 * @extends Ext.util.Observable
	 * <p>The class encapsulates a connection to the page's originating domain, allowing requests to be made
	 * either to a configured URL, or to a URL specified at request time.</p>
	 * <p>Requests made by this class are asynchronous, and will return immediately. No data from
	 * the server will be available to the statement immediately following the {@link #request} call.
	 * To process returned data, use a
	 * <a href="#request-option-success" ext:member="request-option-success" ext:cls="Ext.data.Connection">success callback</a>
	 * in the request options object,
	 * or an {@link #requestcomplete event listener}.</p>
	 * <p><h3>File Uploads</h3><a href="#request-option-isUpload" ext:member="request-option-isUpload" ext:cls="Ext.data.Connection">File uploads</a> are not performed using normal "Ajax" techniques, that
	 * is they are <b>not</b> performed using XMLHttpRequests. Instead the form is submitted in the standard
	 * manner with the DOM <tt>&lt;form></tt> element temporarily modified to have its
	 * <a href="http://www.w3.org/TR/REC-html40/present/frames.html#adef-target">target</a> set to refer
	 * to a dynamically generated, hidden <tt>&lt;iframe></tt> which is inserted into the document
	 * but removed after the return data has been gathered.</p>
	 * <p>The server response is parsed by the browser to create the document for the IFRAME. If the
	 * server is using JSON to send the return object, then the
	 * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.17">Content-Type</a> header
	 * must be set to "text/html" in order to tell the browser to insert the text unchanged into the document body.</p>
	 * <p>Characters which are significant to an HTML parser must be sent as HTML entities, so encode
	 * "&lt;" as "&amp;lt;", "&amp;" as "&amp;amp;" etc.</p>
	 * <p>The response text is retrieved from the document, and a fake XMLHttpRequest object
	 * is created containing a <tt>responseText</tt> property in order to conform to the
	 * requirements of event handlers and callbacks.</p>
	 * <p>Be aware that file upload packets are sent with the content type <a href="http://www.faqs.org/rfcs/rfc2388.html">multipart/form</a>
	 * and some server technologies (notably JEE) may require some custom processing in order to
	 * retrieve parameter names and parameter values from the packet content.</p>
	 * @constructor
	 * @param {Object} config a configuration object.
	 */
	Ext.data.Connection = function(config){	
	    Ext.apply(this, config);
	    this.addEvents(
	        /**
	         * @event beforerequest
	         * Fires before a network request is made to retrieve a data object.
	         * @param {Connection} conn This Connection object.
	         * @param {Object} options The options config object passed to the {@link #request} method.
	         */
	        BEFOREREQUEST,
	        /**
	         * @event requestcomplete
	         * Fires if the request was successfully completed.
	         * @param {Connection} conn This Connection object.
	         * @param {Object} response The XHR object containing the response data.
	         * See <a href="http://www.w3.org/TR/XMLHttpRequest/">The XMLHttpRequest Object</a>
	         * for details.
	         * @param {Object} options The options config object passed to the {@link #request} method.
	         */
	        REQUESTCOMPLETE,
	        /**
	         * @event requestexception
	         * Fires if an error HTTP status was returned from the server.
	         * See <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html">HTTP Status Code Definitions</a>
	         * for details of HTTP status codes.
	         * @param {Connection} conn This Connection object.
	         * @param {Object} response The XHR object containing the response data.
	         * See <a href="http://www.w3.org/TR/XMLHttpRequest/">The XMLHttpRequest Object</a>
	         * for details.
	         * @param {Object} options The options config object passed to the {@link #request} method.
	         */
	        REQUESTEXCEPTION
	    );
	    Ext.data.Connection.superclass.constructor.call(this);
	};

	// private
    function handleResponse(response){
        this.transId = false;
        var options = response.argument.options;
        response.argument = options ? options.argument : null;
        this.fireEvent(REQUESTCOMPLETE, this, response, options);
        if(options.success) options.success.call(options.scope, response, options);
        if(options.callback) options.callback.call(options.scope, options, true, response);
    }

    // private
    function handleFailure(response, e){
        this.transId = false;
        var options = response.argument.options;
        response.argument = options ? options.argument : null;
        this.fireEvent(REQUESTEXCEPTION, this, response, options, e);
        if(options.failure) options.failure.call(options.scope, response, options);
        if(options.callback) options.callback.call(options.scope, options, false, response);
    }

	// private
    function doFormUpload(o, ps, url){
        var id = Ext.id(),
        	doc = document,
        	frame = doc.createElement('iframe'),
        	form = Ext.getDom(o.form),
        	hiddens = [],
        	hd;
        	
        frame.id = frame.name = id;         
        frame.className = 'x-hidden';        
        frame.src = Ext.SSL_SECURE_URL; // for IE        
        doc.body.appendChild(frame);

        if(Ext.isIE){
        	doc.frames[id].name = id;
        }
        
        form.target = id;
        form.method = POST;
        form.enctype = form.encoding = 'multipart/form-data';        
        form.action = url || "";
        
        // add dynamic params            
        ps = Ext.urlDecode(ps, false);
        for(var k in ps){
            if(ps.hasOwnProperty(k)){
                hd = doc.createElement('input');
                hd.type = 'hidden';                    
                hd.value = ps[hd.name = k];
                form.appendChild(hd);
                hiddens.push(hd);
            }
        }        

        function cb(){
            var me = this,
            	// bogus response object
            	r = {responseText : '',
	                 responseXML : null,
	                 argument : o.argument},
            	doc,
            	firstChild;

            try { 
                doc = frame.contentWindow.document || frame.contentDocument || WINDOW.frames[id].document;
                if (doc) {
	            	if (doc.body) {
		            	if (/textarea/i.test((firstChild = doc.body.firstChild || {}).tagName)) { // json response wrapped in textarea	                    
                        	r.responseText = firstChild.value;
	                    } else {
	                        r.responseText = doc.body.innerHTML;
	                    }
	            	} else {
		            	r.responseXML = doc.XMLDocument || doc;
		           	}
                }
            }
            catch(e) {}

            Ext.EventManager.removeListener(frame, LOAD, cb, me);

            me.fireEvent(REQUESTCOMPLETE, me, r, o);

            Ext.callback(o.success, o.scope, [r, o]);
            Ext.callback(o.callback, o.scope, [o, true, r]);

            if(!me.debugUploads){
                setTimeout(function(){Ext.removeNode(frame);}, 100);
            }
        }

        Ext.EventManager.on(frame, LOAD, cb, this);
        form.submit();
        
        Ext.each(hiddens, function(h) {
	        Ext.removeNode(h);
        });
    }
    	    
	Ext.extend(Ext.data.Connection, Ext.util.Observable, {
	    /**
	     * @cfg {String} url (Optional) The default URL to be used for requests to the server. (defaults to undefined)
	     */
	    /**
	     * @cfg {Object} extraParams (Optional) An object containing properties which are used as
	     * extra parameters to each request made by this object. (defaults to undefined)
	     */
	    /**
	     * @cfg {Object} defaultHeaders (Optional) An object containing request headers which are added
	     *  to each request made by this object. (defaults to undefined)
	     */
	    /**
	     * @cfg {String} method (Optional) The default HTTP method to be used for requests.
	     * (defaults to undefined; if not set, but {@link #request} params are present, POST will be used;
	     * otherwise, GET will be used.)
	     */
	    /**
	     * @cfg {Number} timeout (Optional) The timeout in milliseconds to be used for requests. (defaults to 30000)
	     */
	    timeout : 30000,
	    /**
	     * @cfg {Boolean} autoAbort (Optional) Whether this request should abort any pending requests. (defaults to false)
	     * @type Boolean
	     */
	    autoAbort:false,
	
	    /**
	     * @cfg {Boolean} disableCaching (Optional) True to add a unique cache-buster param to GET requests. (defaults to true)
	     * @type Boolean
	     */
	    disableCaching: true,
	    
	    /**
	     * @cfg {String} disableCachingParam (Optional) Change the parameter which is sent went disabling caching
	     * through a cache buster. Defaults to '_dc'
	     * @type String
	     */
	    disableCachingParam: '_dc',
        
	    /**
	     * <p>Sends an HTTP request to a remote server.</p>
	     * <p><b>Important:</b> Ajax server requests are asynchronous, and this call will
	     * return before the response has been received. Process any returned data
	     * in a callback function.</p>
	     * <pre><code>
Ext.Ajax.request({
   url: 'ajax_demo/sample.json',
   success: function(response, opts) {
      var obj = Ext.decode(response.responseText);
      console.dir(obj);
   },
   failure: function(response, opts) {
      console.log('server-side failure with status code ' + response.status);
   }
});
	     * </code></pre>
	     * <p>To execute a callback function in the correct scope, use the <tt>scope</tt> option.</p>
	     * @param {Object} options An object which may contain the following properties:<ul>
	     * <li><b>url</b> : String/Function (Optional)<div class="sub-desc">The URL to
	     * which to send the request, or a function to call which returns a URL string. The scope of the
	     * function is specified by the <tt>scope</tt> option. Defaults to the configured
	     * <tt>{@link #url}</tt>.</div></li>
	     * <li><b>params</b> : Object/String/Function (Optional)<div class="sub-desc">
	     * An object containing properties which are used as parameters to the
	     * request, a url encoded string or a function to call to get either. The scope of the function
	     * is specified by the <tt>scope</tt> option.</div></li>
	     * <li><b>method</b> : String (Optional)<div class="sub-desc">The HTTP method to use
	     * for the request. Defaults to the configured method, or if no method was configured,
	     * "GET" if no parameters are being sent, and "POST" if parameters are being sent.  Note that
	     * the method name is case-sensitive and should be all caps.</div></li>
	     * <li><b>callback</b> : Function (Optional)<div class="sub-desc">The
	     * function to be called upon receipt of the HTTP response. The callback is
	     * called regardless of success or failure and is passed the following
	     * parameters:<ul>
	     * <li><b>options</b> : Object<div class="sub-desc">The parameter to the request call.</div></li>
	     * <li><b>success</b> : Boolean<div class="sub-desc">True if the request succeeded.</div></li>
	     * <li><b>response</b> : Object<div class="sub-desc">The XMLHttpRequest object containing the response data. 
	     * See <a href="http://www.w3.org/TR/XMLHttpRequest/">http://www.w3.org/TR/XMLHttpRequest/</a> for details about 
	     * accessing elements of the response.</div></li>
	     * </ul></div></li>
	     * <li><a id="request-option-success"></a><b>success</b> : Function (Optional)<div class="sub-desc">The function
	     * to be called upon success of the request. The callback is passed the following
	     * parameters:<ul>
	     * <li><b>response</b> : Object<div class="sub-desc">The XMLHttpRequest object containing the response data.</div></li>
	     * <li><b>options</b> : Object<div class="sub-desc">The parameter to the request call.</div></li>
	     * </ul></div></li>