4 * Copyright(c) 2006-2007, Ext JS, LLC.
6 * Originally Released Under LGPL - original licence link has changed is not relivant.
9 * <script type="text/javascript">
12 * @class Roo.tree.TreeLoader
13 * @extends Roo.util.Observable
14 * A TreeLoader provides for lazy loading of an {@link Roo.tree.TreeNode}'s child
15 * nodes from a specified URL. The response must be a javascript Array definition
16 * who's elements are node definition objects. eg:
21 { 'id': 1, 'text': 'A folder Node', 'leaf': false },
22 { 'id': 2, 'text': 'A leaf Node', 'leaf': true }
29 * The old style respose with just an array is still supported, but not recommended.
32 * A server request is sent, and child nodes are loaded only when a node is expanded.
33 * The loading node's id is passed to the server under the parameter name "node" to
34 * enable the server to produce the correct child nodes.
36 * To pass extra parameters, an event handler may be attached to the "beforeload"
37 * event, and the parameters specified in the TreeLoader's baseParams property:
39 myTreeLoader.on("beforeload", function(treeLoader, node) {
40 this.baseParams.category = node.attributes.category;
45 * This would pass an HTTP parameter called "category" to the server containing
46 * the value of the Node's "category" attribute.
48 * Creates a new Treeloader.
49 * @param {Object} config A config object containing config properties.
51 Roo.tree.TreeLoader = function(config){
53 this.requestMethod = "POST";
54 Roo.apply(this, config);
60 * Fires before a network request is made to retrieve the Json text which specifies a node's children.
61 * @param {Object} This TreeLoader object.
62 * @param {Object} node The {@link Roo.tree.TreeNode} object being loaded.
63 * @param {Object} callback The callback function specified in the {@link #load} call.
68 * Fires when the node has been successfuly loaded.
69 * @param {Object} This TreeLoader object.
70 * @param {Object} node The {@link Roo.tree.TreeNode} object being loaded.
71 * @param {Object} response The response object containing the data from the server.
75 * @event loadexception
76 * Fires if the network request failed.
77 * @param {Object} This TreeLoader object.
78 * @param {Object} node The {@link Roo.tree.TreeNode} object being loaded.
79 * @param {Object} response The response object containing the data from the server.
84 * Fires before a node is created, enabling you to return custom Node types
85 * @param {Object} This TreeLoader object.
86 * @param {Object} attr - the data returned from the AJAX call (modify it to suit)
91 Roo.tree.TreeLoader.superclass.constructor.call(this);
94 Roo.extend(Roo.tree.TreeLoader, Roo.util.Observable, {
96 * @cfg {String} dataUrl The URL from which to request a Json string which
97 * specifies an array of node definition object representing the child nodes
101 * @cfg {String} requestMethod either GET or POST
102 * defaults to POST (due to BC)
106 * @cfg {Object} baseParams (optional) An object containing properties which
107 * specify HTTP parameters to be passed to each request for child nodes.
110 * @cfg {Object} baseAttrs (optional) An object containing attributes to be added to all nodes
111 * created by this loader. If the attributes sent by the server have an attribute in this object,
112 * they take priority.
115 * @cfg {Object} uiProviders (optional) An object containing properties which
117 * DEPRECATED - use 'create' event handler to modify attributes - which affect creation.
118 * specify custom {@link Roo.tree.TreeNodeUI} implementations. If the optional
119 * <i>uiProvider</i> attribute of a returned child node is a string rather
120 * than a reference to a TreeNodeUI implementation, this that string value
121 * is used as a property name in the uiProviders object. You can define the provider named
122 * 'default' , and this will be used for all nodes (if no uiProvider is delivered by the node data)
127 * @cfg {Boolean} clearOnLoad (optional) Default to true. Remove previously existing
128 * child nodes before loading.
133 * @cfg {String} root (optional) Default to false. Use this to read data from an object
134 * property on loading, rather than expecting an array. (eg. more compatible to a standard
135 * Grid query { data : [ .....] }
140 * @cfg {String} queryParam (optional)
141 * Name of the query as it will be passed on the querystring (defaults to 'node')
142 * eg. the request will be ?node=[id]
149 * Load an {@link Roo.tree.TreeNode} from the URL specified in the constructor.
150 * This is called automatically when a node is expanded, but may be used to reload
151 * a node (or append new children if the {@link #clearOnLoad} option is false.)
152 * @param {Roo.tree.TreeNode} node
153 * @param {Function} callback
155 load : function(node, callback){
156 if(this.clearOnLoad){
157 while(node.firstChild){
158 node.removeChild(node.firstChild);
161 if(node.attributes.children){ // preloaded json children
162 var cs = node.attributes.children;
163 for(var i = 0, len = cs.length; i < len; i++){
164 node.appendChild(this.createNode(cs[i]));
166 if(typeof callback == "function"){
169 }else if(this.dataUrl){
170 this.requestData(node, callback);
174 getParams: function(node){
175 var buf = [], bp = this.baseParams;
177 if(typeof bp[key] != "function"){
178 buf.push(encodeURIComponent(key), "=", encodeURIComponent(bp[key]), "&");
181 var n = this.queryParam === false ? 'node' : this.queryParam;
182 buf.push(n + "=", encodeURIComponent(node.id));
186 requestData : function(node, callback){
187 if(this.fireEvent("beforeload", this, node, callback) !== false){
188 this.transId = Roo.Ajax.request({
189 method:this.requestMethod,
190 url: this.dataUrl||this.url,
191 success: this.handleResponse,
192 failure: this.handleFailure,
194 argument: {callback: callback, node: node},
195 params: this.getParams(node)
198 // if the load is cancelled, make sure we notify
199 // the node that we are done
200 if(typeof callback == "function"){
206 isLoading : function(){
207 return this.transId ? true : false;
211 if(this.isLoading()){
212 Roo.Ajax.abort(this.transId);
217 createNode : function(attr)
219 // apply baseAttrs, nice idea Corey!
221 Roo.applyIf(attr, this.baseAttrs);
223 if(this.applyLoader !== false){
226 // uiProvider = depreciated..
228 if(typeof(attr.uiProvider) == 'string'){
229 attr.uiProvider = this.uiProviders[attr.uiProvider] ||
230 /** eval:var:attr */ eval(attr.uiProvider);
232 if(typeof(this.uiProviders['default']) != 'undefined') {
233 attr.uiProvider = this.uiProviders['default'];
236 this.fireEvent('create', this, attr);
238 attr.leaf = typeof(attr.leaf) == 'string' ? attr.leaf * 1 : attr.leaf;
240 new Roo.tree.TreeNode(attr) :
241 new Roo.tree.AsyncTreeNode(attr));
244 processResponse : function(response, node, callback)
246 var json = response.responseText;
249 var o = Roo.decode(json);
251 if (this.root === false && typeof(o.success) != undefined) {
252 this.root = 'data'; // the default behaviour for list like data..
255 if (this.root !== false && !o.success) {
256 // it's a failure condition.
257 var a = response.argument;
258 this.fireEvent("loadexception", this, a.node, response);
259 Roo.log("Load failed - should have a handler really");
265 if (this.root !== false) {
269 for(var i = 0, len = o.length; i < len; i++){
270 var n = this.createNode(o[i]);
275 if(typeof callback == "function"){
276 callback(this, node);
279 this.handleFailure(response);
283 handleResponse : function(response){
284 this.transId = false;
285 var a = response.argument;
286 this.processResponse(response, a.node, a.callback);
287 this.fireEvent("load", this, a.node, response);
290 handleFailure : function(response)
292 // should handle failure better..
293 this.transId = false;
294 var a = response.argument;
295 this.fireEvent("loadexception", this, a.node, response);
296 if(typeof a.callback == "function"){
297 a.callback(this, a.node);