Roo/tree/AsyncTreeNode.js

/*
 * Based on:
 * Ext JS Library 1.1.1
 * Copyright(c) 2006-2007, Ext JS, LLC.
 *
 * Originally Released Under LGPL - original licence link has changed is not relivant.
 *
 * Fork - LGPL
 * <script type="text/javascript">
 */

/**
 * @class Roo.tree.AsyncTreeNode
 * @extends Roo.tree.TreeNode
 * @cfg {TreeLoader} loader A TreeLoader to be used by this node (defaults to the loader defined on the tree)
 * @constructor
 * @param {Object/String} attributes The attributes/config for the node or just a string with the text for the node 
 */
 Roo.tree.AsyncTreeNode = function(config){
    this.loaded = false;
    this.loading = false;
    Roo.tree.AsyncTreeNode.superclass.constructor.apply(this, arguments);
    /**
    * @event beforeload
    * Fires before this node is loaded, return false to cancel
    * @param {Node} this This node
    */
    this.addEvents({'beforeload':true, 'load': true});
    /**
    * @event load
    * Fires when this node is loaded
    * @param {Node} this This node
    */
    /**
     * The loader used by this node (defaults to using the tree's defined loader)
     * @type TreeLoader
     * @property loader
     */
};
Roo.extend(Roo.tree.AsyncTreeNode, Roo.tree.TreeNode, {
    expand : function(deep, anim, callback){
        if(this.loading){ // if an async load is already running, waiting til it's done
            var timer;
            var f = function(){
                if(!this.loading){ // done loading
                    clearInterval(timer);
                    this.expand(deep, anim, callback);
                }
            }.createDelegate(this);
            timer = setInterval(f, 200);
            return;
        }
        if(!this.loaded){
            if(this.fireEvent("beforeload", this) === false){
                return;
            }
            this.loading = true;
            this.ui.beforeLoad(this);
            var loader = this.loader || this.attributes.loader || this.getOwnerTree().getLoader();
            if(loader){
                loader.load(this, this.loadComplete.createDelegate(this, [deep, anim, callback]));
                return;
            }
        }
        Roo.tree.AsyncTreeNode.superclass.expand.call(this, deep, anim, callback);
    },

    /**
     * Returns true if this node is currently loading
     * @return {Boolean}
     */
    isLoading : function(){
        return this.loading;
    },

    loadComplete : function(deep, anim, callback){
        this.loading = false;
        this.loaded = true;
        this.ui.afterLoad(this);
        this.fireEvent("load", this);
        this.expand(deep, anim, callback);
    },

    /**
     * Returns true if this node has been loaded
     * @return {Boolean}
     */
    isLoaded : function(){
        return this.loaded;
    },

    hasChildNodes : function(){
        if(!this.isLeaf() && !this.loaded){
            return true;
        }else{
            return Roo.tree.AsyncTreeNode.superclass.hasChildNodes.call(this);
        }
    },

    /**
     * Trigger a reload for this node
     * @param {Function} callback
     */
    reload : function(callback){
        this.collapse(false, false);
        while(this.firstChild){
            this.removeChild(this.firstChild);
        }
        this.childrenRendered = false;
        this.loaded = false;
        if(this.isHiddenRoot()){
            this.expanded = false;
        }
        this.expand(false, false, callback);
    }
});