Extjs4 重写Ext.data.TreeStore的load方法，不使多次加载

Ext.override(Ext.data.TreeStore, {

load : function(options) {

options = options || {};

options.params = options.params || {};

var me = this, node = options.node || me.tree.getRootNode(), root;

// If there is not a node it means the user hasnt defined a rootnode

// yet. In this case lets just

// create one for them.

if (!node) {

node = me.setRootNode( {

expanded : true

});

}

if (me.clearOnLoad) {

node.removeAll(false);

}

Ext.applyIf(options, {

node : node

});

options.params[me.nodeParam] = node ? node.getId() : 'root';

if (node) {

node.set('loading', true);

}

return me.callParent( [ options ]);

}

});