/*!
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* Ext JS Library 3.1.0
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* Copyright(c) 2006-2009 Ext JS, LLC
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* licensing@extjs.com
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* http://www.extjs.com/license
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*/
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/**
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* @class Ext.direct.PollingProvider
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* @extends Ext.direct.JsonProvider
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*
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* <p>Provides for repetitive polling of the server at distinct {@link #interval intervals}.
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* The initial request for data originates from the client, and then is responded to by the
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* server.</p>
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*
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* <p>All configurations for the PollingProvider should be generated by the server-side
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* API portion of the Ext.Direct stack.</p>
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*
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* <p>An instance of PollingProvider may be created directly via the new keyword or by simply
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* specifying <tt>type = 'polling'</tt>. For example:</p>
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* <pre><code>
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var pollA = new Ext.direct.PollingProvider({
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type:'polling',
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url: 'php/pollA.php',
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});
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Ext.Direct.addProvider(pollA);
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pollA.disconnect();
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Ext.Direct.addProvider(
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{
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type:'polling',
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url: 'php/pollB.php',
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id: 'pollB-provider'
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}
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);
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var pollB = Ext.Direct.getProvider('pollB-provider');
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* </code></pre>
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*/
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Ext.direct.PollingProvider = Ext.extend(Ext.direct.JsonProvider, {
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/**
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* @cfg {Number} priority
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* Priority of the request (defaults to <tt>3</tt>). See {@link Ext.direct.Provider#priority}.
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*/
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// override default priority
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priority: 3,
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/**
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* @cfg {Number} interval
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* How often to poll the server-side in milliseconds (defaults to <tt>3000</tt> - every
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* 3 seconds).
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*/
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interval: 3000,
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/**
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* @cfg {Object} baseParams An object containing properties which are to be sent as parameters
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* on every polling request
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*/
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/**
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* @cfg {String/Function} url
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* The url which the PollingProvider should contact with each request. This can also be
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* an imported Ext.Direct method which will accept the baseParams as its only argument.
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*/
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// private
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constructor : function(config){
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Ext.direct.PollingProvider.superclass.constructor.call(this, config);
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this.addEvents(
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/**
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* @event beforepoll
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* Fired immediately before a poll takes place, an event handler can return false
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* in order to cancel the poll.
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* @param {Ext.direct.PollingProvider}
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*/
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'beforepoll',
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/**
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* @event poll
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* This event has not yet been implemented.
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* @param {Ext.direct.PollingProvider}
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*/
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'poll'
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);
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},
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// inherited
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isConnected: function(){
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return !!this.pollTask;
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},
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/**
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* Connect to the server-side and begin the polling process. To handle each
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* response subscribe to the data event.
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*/
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connect: function(){
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if(this.url && !this.pollTask){
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this.pollTask = Ext.TaskMgr.start({
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run: function(){
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if(this.fireEvent('beforepoll', this) !== false){
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if(typeof this.url == 'function'){
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this.url(this.baseParams);
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}else{
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Ext.Ajax.request({
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url: this.url,
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callback: this.onData,
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scope: this,
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params: this.baseParams
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});
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}
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}
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},
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interval: this.interval,
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scope: this
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});
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this.fireEvent('connect', this);
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}else if(!this.url){
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throw 'Error initializing PollingProvider, no url configured.';
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}
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},
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/**
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* Disconnect from the server-side and stop the polling process. The disconnect
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* event will be fired on a successful disconnect.
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*/
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disconnect: function(){
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if(this.pollTask){
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Ext.TaskMgr.stop(this.pollTask);
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delete this.pollTask;
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this.fireEvent('disconnect', this);
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}
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},
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// private
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onData: function(opt, success, xhr){
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if(success){
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var events = this.getEvents(xhr);
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for(var i = 0, len = events.length; i < len; i++){
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var e = events[i];
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this.fireEvent('data', this, e);
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}
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}else{
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var e = new Ext.Direct.ExceptionEvent({
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data: e,
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code: Ext.Direct.exceptions.TRANSPORT,
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message: 'Unable to connect to the server.',
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xhr: xhr
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});
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this.fireEvent('data', this, e);
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}
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}
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});
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Ext.Direct.PROVIDERS['polling'] = Ext.direct.PollingProvider;
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