Steps to overriding Sencha ExtJS standard component functionality (Ext.tree.Panel & Ext.data.TreeStore as two examples)

Question

Suppose I am extending a standard Sencha ExtJS 4 widget/component, and I found a bunch of things that don\'t work the way I want them to, or perhaps they are just broken and

Answer 1

Override the functions which you think are not working correctly or the way you want it to work

Example

Ext.define('MyApp.store.TreeGridStore', {
extend: 'Ext.data.TreeStore',
getTotalCount : function() {
    if(!this.proxy.reader.rawData) return 0;
    this.totalCount = this.proxy.reader.rawData.recordCount;
    return this.totalCount;
},  
....

In the above example I want the getTotalCount function to calculate the count differently, so I extended the treestore and overrided the method.