/**
+ * @class Ext.ElementLoader
+ * A class used to load remote content to an Element. Sample usage:
+ * <pre><code>
+Ext.get('el').load({
+ url: 'myPage.php',
+ scripts: true,
+ params: {
+ id: 1
+ }
+});
+ * </code></pre>
+ * <p>
+ * In general this class will not be instanced directly, rather the {@link Ext.core.Element#load} method
+ * will be used.
+ * </p>
+ */
+Ext.define('Ext.ElementLoader', {
+
+ /* Begin Definitions */
+
+ mixins: {
+ observable: 'Ext.util.Observable'
+ },
+
+ uses: [
+ 'Ext.data.Connection',
+ 'Ext.Ajax'
+ ],
+
+ statics: {
+ Renderer: {
+ Html: function(loader, response, active){
+ loader.getTarget().update(response.responseText, active.scripts === true);
+ return true;
+ }
+ }
+ },
+
+ /* End Definitions */
+
+ /**
+ * @cfg {String} url The url to retrieve the content from. Defaults to <tt>null</tt>.
+ */
+ url: null,
+
+ /**
+ * @cfg {Object} params Any params to be attached to the Ajax request. These parameters will
+ * be overridden by any params in the load options. Defaults to <tt>null</tt>.
+ */
+ params: null,
+
+ /**
+ * @cfg {Object} baseParams Params that will be attached to every request. These parameters
+ * will not be overridden by any params in the load options. Defaults to <tt>null</tt>.
+ */
+ baseParams: null,
+
+ /**
+ * @cfg {Boolean/Object} autoLoad True to have the loader make a request as soon as it is created. Defaults to <tt>false</tt>.
+ * This argument can also be a set of options that will be passed to {@link #load} is called.
+ */
+ autoLoad: false,
+
+ /**
+ * @cfg {Mixed} target The target element for the loader. It can be the DOM element, the id or an Ext.Element.
+ */
+ target: null,
+
+ /**
+ * @cfg {Mixed} loadMask True or a string to show when the element is loading.
+ */
+ loadMask: false,
+
+ /**
+ * @cfg {Object} ajaxOptions Any additional options to be passed to the request, for example timeout or headers. Defaults to <tt>null</tt>.
+ */
+ ajaxOptions: null,
+
+ /**
+ * @cfg {Boolean} scripts True to parse any inline script tags in the response.
+ */
+ scripts: false,
+
+ /**
+ * @cfg {Function} success A function to be called when a load request is successful.
+ */
+
+ /**
+ * @cfg {Function} failure A function to be called when a load request fails.
+ */
+
+ /**
+ * @cfg {Object} scope The scope to execute the {@link #success} and {@link #failure} functions in.
+ */
+
+ /**
+ * @cfg {Function} renderer A custom function to render the content to the element. The passed parameters
+ * are
+ * <ul>
+ * <li>The loader</li>
+ * <li>The response</li>
+ * <li>The active request</li>
+ * </ul>
+ */
+
+ isLoader: true,
+
+ constructor: function(config) {
+ var me = this,
+ autoLoad;
+
+ config = config || {};
+ Ext.apply(me, config);
+ me.setTarget(me.target);
+ me.addEvents(
+ /**
+ * @event beforeload
+ * Fires before a load request is made to the server.
+ * Returning false from an event listener can prevent the load
+ * from occurring.
+ * @param {Ext.ElementLoader} this
+ * @param {Object} options The options passed to the request
+ */
+ 'beforeload',
+
+ /**
+ * @event exception
+ * Fires after an unsuccessful load.
+ * @param {Ext.ElementLoader} this
+ * @param {Object} response The response from the server
+ * @param {Object} options The options passed to the request
+ */
+ 'exception',
+
+ /**
+ * @event exception
+ * Fires after a successful load.
+ * @param {Ext.ElementLoader} this
+ * @param {Object} response The response from the server
+ * @param {Object} options The options passed to the request
+ */
+ 'load'
+ );
+
+ // don't pass config because we have already applied it.
+ me.mixins.observable.constructor.call(me);
+
+ if (me.autoLoad) {
+ autoLoad = me.autoLoad;
+ if (autoLoad === true) {
+ autoLoad = {};
+ }
+ me.load(autoLoad);
+ }
+ },
+
+ /**
+ * Set an {Ext.Element} as the target of this loader. Note that if the target is changed,
+ * any active requests will be aborted.
+ * @param {Mixed} target The element
+ */
+ setTarget: function(target){
+ var me = this;
+ target = Ext.get(target);
+ if (me.target && me.target != target) {
+ me.abort();
+ }
+ me.target = target;
+ },
+
+ /**
+ * Get the target of this loader.
+ * @return {Ext.Component} target The target, null if none exists.
+ */
+ getTarget: function(){
+ return this.target || null;
+ },
+
+ /**
+ * Aborts the active load request
+ */
+ abort: function(){
+ var active = this.active;
+ if (active !== undefined) {
+ Ext.Ajax.abort(active.request);
+ if (active.mask) {
+ this.removeMask();
+ }
+ delete this.active;
+ }
+ },
+
+ /**
+ * Remove the mask on the target
+ * @private
+ */
+ removeMask: function(){
+ this.target.unmask();
+ },
+
+ /**
+ * Add the mask on the target
+ * @private
+ * @param {Mixed} mask The mask configuration
+ */
+ addMask: function(mask){
+ this.target.mask(mask === true ? null : mask);
+ },
+
+ /**
+ * Load new data from the server.
+ * @param {Object} options The options for the request. They can be any configuration option that can be specified for
+ * the class, with the exception of the target option. Note that any options passed to the method will override any
+ * class defaults.
+ */
+ load: function(options) {
+ //<debug>
+ if (!this.target) {
+ Ext.Error.raise('A valid target is required when loading content');
+ }
+ //</debug>
+
+ options = Ext.apply({}, options);
+
+ var me = this,
+ target = me.target,
+ mask = Ext.isDefined(options.loadMask) ? options.loadMask : me.loadMask,
+ params = Ext.apply({}, options.params),
+ ajaxOptions = Ext.apply({}, options.ajaxOptions),
+ callback = options.callback || me.callback,
+ scope = options.scope || me.scope || me,
+ request;
+
+ Ext.applyIf(ajaxOptions, me.ajaxOptions);
+ Ext.applyIf(options, ajaxOptions);
+
+ Ext.applyIf(params, me.params);
+ Ext.apply(params, me.baseParams);
+
+ Ext.applyIf(options, {
+ url: me.url
+ });
+
+ //<debug>
+ if (!options.url) {
+ Ext.Error.raise('You must specify the URL from which content should be loaded');
+ }
+ //</debug>
+
+ Ext.apply(options, {
+ scope: me,
+ params: params,
+ callback: me.onComplete
+ });
+
+ if (me.fireEvent('beforeload', me, options) === false) {
+ return;
+ }
+
+ if (mask) {
+ me.addMask(mask);
+ }
+
+ request = Ext.Ajax.request(options);
+ me.active = {
+ request: request,
+ options: options,
+ mask: mask,
+ scope: scope,
+ callback: callback,
+ success: options.success || me.success,
+ failure: options.failure || me.failure,
+ renderer: options.renderer || me.renderer,
+ scripts: Ext.isDefined(options.scripts) ? options.scripts : me.scripts
+ };
+ me.setOptions(me.active, options);
+ },
+
+ /**
+ * Set any additional options on the active request
+ * @private
+ * @param {Object} active The active request
+ * @param {Object} options The initial options
+ */
+ setOptions: Ext.emptyFn,
+
+ /**
+ * Parse the response after the request completes
+ * @private
+ * @param {Object} options Ajax options
+ * @param {Boolean} success Success status of the request
+ * @param {Object} response The response object
+ */
+ onComplete: function(options, success, response) {
+ var me = this,
+ active = me.active,
+ scope = active.scope,
+ renderer = me.getRenderer(active.renderer);
+
+
+ if (success) {
+ success = renderer.call(me, me, response, active);
+ }
+
+ if (success) {
+ Ext.callback(active.success, scope, [me, response, options]);
+ me.fireEvent('load', me, response, options);
+ } else {
+ Ext.callback(active.failure, scope, [me, response, options]);
+ me.fireEvent('exception', me, response, options);
+ }
+ Ext.callback(active.callback, scope, [me, success, response, options]);
+
+ if (active.mask) {
+ me.removeMask();
+ }
+
+ delete me.active;
+ },
+
+ /**
+ * Gets the renderer to use
+ * @private
+ * @param {String/Function} renderer The renderer to use
+ * @return {Function} A rendering function to use.
+ */
+ getRenderer: function(renderer){
+ if (Ext.isFunction(renderer)) {
+ return renderer;
+ }
+ return this.statics().Renderer.Html;
+ },
+
+ /**
+ * Automatically refreshes the content over a specified period.
+ * @param {Number} interval The interval to refresh in ms.
+ * @param {Object} options (optional) The options to pass to the load method. See {@link #load}
+ */
+ startAutoRefresh: function(interval, options){
+ var me = this;
+ me.stopAutoRefresh();
+ me.autoRefresh = setInterval(function(){
+ me.load(options);
+ }, interval);
+ },
+
+ /**
+ * Clears any auto refresh. See {@link #startAutoRefresh}.
+ */
+ stopAutoRefresh: function(){
+ clearInterval(this.autoRefresh);
+ delete this.autoRefresh;
+ },
+
+ /**
+ * Checks whether the loader is automatically refreshing. See {@link #startAutoRefresh}.
+ * @return {Boolean} True if the loader is automatically refreshing
+ */
+ isAutoRefreshing: function(){
+ return Ext.isDefined(this.autoRefresh);
+ },
+
+ /**
+ * Destroys the loader. Any active requests will be aborted.
+ */
+ destroy: function(){
+ var me = this;
+ me.stopAutoRefresh();
+ delete me.target;
+ me.abort();
+ me.clearListeners();
+ }
+});
+