/*! - * Ext JS Library 3.2.2 - * Copyright(c) 2006-2010 Ext JS, Inc. - * licensing@extjs.com - * http://www.extjs.com/license - */ -/** - * @class Ext.data.ScriptTagProxy - * @extends Ext.data.DataProxy - * An implementation of Ext.data.DataProxy that reads a data object from a URL which may be in a domain - * other than the originating domain of the running page.
- *- * Note that if you are retrieving data from a page that is in a domain that is NOT the same as the originating domain - * of the running page, you must use this class, rather than HttpProxy.
- *- * The content passed back from a server resource requested by a ScriptTagProxy must be executable JavaScript - * source code because it is used as the source inside a <script> tag.
- *- * In order for the browser to process the returned data, the server must wrap the data object - * with a call to a callback function, the name of which is passed as a parameter by the ScriptTagProxy. - * Below is a Java example for a servlet which returns data for either a ScriptTagProxy, or an HttpProxy - * depending on whether the callback name was passed: - *
- *
- *-boolean scriptTag = false; -String cb = request.getParameter("callback"); -if (cb != null) { - scriptTag = true; - response.setContentType("text/javascript"); -} else { - response.setContentType("application/x-json"); -} -Writer out = response.getWriter(); -if (scriptTag) { - out.write(cb + "("); -} -out.print(dataBlock.toJsonString()); -if (scriptTag) { - out.write(");"); -} -Below is a PHP example to do the same thing:
- *-$callback = $_REQUEST['callback']; - -// Create the output object. -$output = array('a' => 'Apple', 'b' => 'Banana'); - -//start output -if ($callback) { - header('Content-Type: text/javascript'); - echo $callback . '(' . json_encode($output) . ');'; -} else { - header('Content-Type: application/x-json'); - echo json_encode($output); -} -Below is the ASP.Net code to do the same thing:
- * - * @constructor - * @param {Object} config A configuration object. - */ -Ext.data.ScriptTagProxy = function(config){ - Ext.apply(this, config); - - Ext.data.ScriptTagProxy.superclass.constructor.call(this, config); - - this.head = document.getElementsByTagName("head")[0]; - - /** - * @event loadexception - * Deprecated in favor of 'exception' event. - * Fires if an exception occurs in the Proxy during data loading. This event can be fired for one of two reasons: - *-String jsonString = "{success: true}"; -String cb = Request.Params.Get("callback"); -String responseString = ""; -if (!String.IsNullOrEmpty(cb)) { - responseString = cb + "(" + jsonString + ")"; -} else { - responseString = jsonString; -} -Response.Write(responseString); -
The server-side processing must read this parameter value, and generate - * javascript output which calls this named function passing the data object as its only parameter. - */ - callbackParam : "callback", -
/** - * @cfg {Boolean} nocache (optional) Defaults to true. Disable caching by adding a unique parameter - * name to the request. - */ - nocache : true, - - /** - * HttpProxy implementation of DataProxy#doRequest - * @param {String} action - * @param {Ext.data.Record/Ext.data.Record[]} rs If action is read, rs will be null - * @param {Object} params An object containing properties which are to be used as HTTP parameters - * for the request to the remote server. - * @param {Ext.data.DataReader} reader The Reader object which converts the data - * object into a block of Ext.data.Records. - * @param {Function} callback The function into which to pass the block of Ext.data.Records. - * The function must be passedthis reference) in which the callback function is executed. Defaults to the browser window.
- * @param {Object} arg An optional argument which is passed to the callback as its second parameter.
- */
- doRequest : function(action, rs, params, reader, callback, scope, arg) {
- var p = Ext.urlEncode(Ext.apply(params, this.extraParams));
-
- var url = this.buildUrl(action, rs);
- if (!url) {
- throw new Ext.data.Api.Error('invalid-url', url);
- }
- url = Ext.urlAppend(url, p);
-
- if(this.nocache){
- url = Ext.urlAppend(url, '_dc=' + (new Date().getTime()));
- }
- var transId = ++Ext.data.ScriptTagProxy.TRANS_ID;
- var trans = {
- id : transId,
- action: action,
- cb : "stcCallback"+transId,
- scriptId : "stcScript"+transId,
- params : params,
- arg : arg,
- url : url,
- callback : callback,
- scope : scope,
- reader : reader
- };
- window[trans.cb] = this.createCallback(action, rs, trans);
- url += String.format("&{0}={1}", this.callbackParam, trans.cb);
- if(this.autoAbort !== false){
- this.abort();
- }
-
- trans.timeoutId = this.handleFailure.defer(this.timeout, this, [trans]);
-
- var script = document.createElement("script");
- script.setAttribute("src", url);
- script.setAttribute("type", "text/javascript");
- script.setAttribute("id", trans.scriptId);
- this.head.appendChild(script);
-
- this.trans = trans;
- },
-
- // @private createCallback
- createCallback : function(action, rs, trans) {
- var self = this;
- return function(res) {
- self.trans = false;
- self.destroyTrans(trans, true);
- if (action === Ext.data.Api.actions.read) {
- self.onRead.call(self, action, trans, res);
- } else {
- self.onWrite.call(self, action, trans, res, rs);
- }
- };
- },
- /**
- * Callback for read actions
- * @param {String} action [Ext.data.Api.actions.create|read|update|destroy]
- * @param {Object} trans The request transaction object
- * @param {Object} res The server response
- * @protected
- */
- onRead : function(action, trans, res) {
- var result;
- try {
- result = trans.reader.readRecords(res);
- }catch(e){
- // @deprecated: fire loadexception
- this.fireEvent("loadexception", this, trans, res, e);
-
- this.fireEvent('exception', this, 'response', action, trans, res, e);
- trans.callback.call(trans.scope||window, null, trans.arg, false);
- return;
- }
- if (result.success === false) {
- // @deprecated: fire old loadexception for backwards-compat.
- this.fireEvent('loadexception', this, trans, res);
-
- this.fireEvent('exception', this, 'remote', action, trans, res, null);
- } else {
- this.fireEvent("load", this, res, trans.arg);
- }
- trans.callback.call(trans.scope||window, result, trans.arg, result.success);
- },
- /**
- * Callback for write actions
- * @param {String} action [Ext.data.Api.actions.create|read|update|destroy]
- * @param {Object} trans The request transaction object
- * @param {Object} res The server response
- * @protected
- */
- onWrite : function(action, trans, response, rs) {
- var reader = trans.reader;
- try {
- // though we already have a response object here in STP, run through readResponse to catch any meta-data exceptions.
- var res = reader.readResponse(action, response);
- } catch (e) {
- this.fireEvent('exception', this, 'response', action, trans, res, e);
- trans.callback.call(trans.scope||window, null, res, false);
- return;
- }
- if(!res.success === true){
- this.fireEvent('exception', this, 'remote', action, trans, res, rs);
- trans.callback.call(trans.scope||window, null, res, false);
- return;
- }
- this.fireEvent("write", this, action, res.data, res, rs, trans.arg );
- trans.callback.call(trans.scope||window, res.data, res, true);
- },
-
- // private
- isLoading : function(){
- return this.trans ? true : false;
- },
-
- /**
- * Abort the current server request.
- */
- abort : function(){
- if(this.isLoading()){
- this.destroyTrans(this.trans);
- }
- },
-
- // private
- destroyTrans : function(trans, isLoaded){
- this.head.removeChild(document.getElementById(trans.scriptId));
- clearTimeout(trans.timeoutId);
- if(isLoaded){
- window[trans.cb] = undefined;
- try{
- delete window[trans.cb];
- }catch(e){}
- }else{
- // if hasn't been loaded, wait for load to remove it to prevent script error
- window[trans.cb] = function(){
- window[trans.cb] = undefined;
- try{
- delete window[trans.cb];
- }catch(e){}
- };
- }
- },
-
- // private
- handleFailure : function(trans){
- this.trans = false;
- this.destroyTrans(trans, false);
- if (trans.action === Ext.data.Api.actions.read) {
- // @deprecated firing loadexception
- this.fireEvent("loadexception", this, null, trans.arg);
- }
-
- this.fireEvent('exception', this, 'response', trans.action, {
- response: null,
- options: trans.arg
- });
- trans.callback.call(trans.scope||window, null, trans.arg, false);
- },
-
- // inherit docs
- destroy: function(){
- this.abort();
- Ext.data.ScriptTagProxy.superclass.destroy.call(this);
- }
-});
-
-
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