/src/main/webapp/ext-4.0/src/direct/PollingProvider.js
https://github.com/garyhellman/cprs · JavaScript · 171 lines · 70 code · 17 blank · 84 comment · 11 complexity · aff5e39f14bb954b92bbf66cb56b263f MD5 · raw file
- /*
- This file is part of Ext JS 4
- Copyright (c) 2011 Sencha Inc
- Contact: http://www.sencha.com/contact
- Commercial Usage
- Licensees holding valid commercial licenses may use this file in accordance with the Commercial Software License Agreement provided with the Software or, alternatively, in accordance with the terms contained in a written agreement between you and Sencha.
- If you are unsure which license is appropriate for your use, please contact the sales department at http://www.sencha.com/contact.
- */
- /**
- * @class Ext.direct.PollingProvider
- * @extends Ext.direct.JsonProvider
- *
- * <p>Provides for repetitive polling of the server at distinct {@link #interval intervals}.
- * The initial request for data originates from the client, and then is responded to by the
- * server.</p>
- *
- * <p>All configurations for the PollingProvider should be generated by the server-side
- * API portion of the Ext.Direct stack.</p>
- *
- * <p>An instance of PollingProvider may be created directly via the new keyword or by simply
- * specifying <tt>type = 'polling'</tt>. For example:</p>
- * <pre><code>
- var pollA = new Ext.direct.PollingProvider({
- type:'polling',
- url: 'php/pollA.php',
- });
- Ext.direct.Manager.addProvider(pollA);
- pollA.disconnect();
- Ext.direct.Manager.addProvider(
- {
- type:'polling',
- url: 'php/pollB.php',
- id: 'pollB-provider'
- }
- );
- var pollB = Ext.direct.Manager.getProvider('pollB-provider');
- * </code></pre>
- */
- Ext.define('Ext.direct.PollingProvider', {
-
- /* Begin Definitions */
-
- extend: 'Ext.direct.JsonProvider',
-
- alias: 'direct.pollingprovider',
-
- uses: ['Ext.direct.ExceptionEvent'],
-
- requires: ['Ext.Ajax', 'Ext.util.DelayedTask'],
-
- /* End Definitions */
-
- /**
- * @cfg {Number} interval
- * How often to poll the server-side in milliseconds. Defaults to every 3 seconds.
- */
- interval: 3000,
- /**
- * @cfg {Object} baseParams
- * An object containing properties which are to be sent as parameters on every polling request
- */
-
- /**
- * @cfg {String/Function} url
- * The url which the PollingProvider should contact with each request. This can also be
- * an imported Ext.Direct method which will accept the baseParams as its only argument.
- */
- // private
- constructor : function(config){
- this.callParent(arguments);
- this.addEvents(
- /**
- * @event beforepoll
- * Fired immediately before a poll takes place, an event handler can return false
- * in order to cancel the poll.
- * @param {Ext.direct.PollingProvider} this
- */
- 'beforepoll',
- /**
- * @event poll
- * This event has not yet been implemented.
- * @param {Ext.direct.PollingProvider} this
- */
- 'poll'
- );
- },
- // inherited
- isConnected: function(){
- return !!this.pollTask;
- },
- /**
- * Connect to the server-side and begin the polling process. To handle each
- * response subscribe to the data event.
- */
- connect: function(){
- var me = this, url = me.url;
-
- if (url && !me.pollTask) {
- me.pollTask = Ext.TaskManager.start({
- run: function(){
- if (me.fireEvent('beforepoll', me) !== false) {
- if (Ext.isFunction(url)) {
- url(me.baseParams);
- } else {
- Ext.Ajax.request({
- url: url,
- callback: me.onData,
- scope: me,
- params: me.baseParams
- });
- }
- }
- },
- interval: me.interval,
- scope: me
- });
- me.fireEvent('connect', me);
- } else if (!url) {
- //<debug>
- Ext.Error.raise('Error initializing PollingProvider, no url configured.');
- //</debug>
- }
- },
- /**
- * Disconnect from the server-side and stop the polling process. The disconnect
- * event will be fired on a successful disconnect.
- */
- disconnect: function(){
- var me = this;
-
- if (me.pollTask) {
- Ext.TaskManager.stop(me.pollTask);
- delete me.pollTask;
- me.fireEvent('disconnect', me);
- }
- },
- // private
- onData: function(opt, success, response){
- var me = this,
- i = 0,
- len,
- events;
-
- if (success) {
- events = me.createEvents(response);
- for (len = events.length; i < len; ++i) {
- me.fireEvent('data', me, events[i]);
- }
- } else {
- me.fireEvent('data', me, Ext.create('Ext.direct.ExceptionEvent', {
- data: null,
- code: Ext.direct.Manager.self.exceptions.TRANSPORT,
- message: 'Unable to connect to the server.',
- xhr: response
- }));
- }
- }
- });