Stores are a collection of model instances that allow these models to be manipulated (for example, sorted, filtered, searched, and so on). They also provide a platform for backend interaction. Many of Ext JS' components can be bound to data stores and take care of a lot of the plumbing required to react to changes in the data held within it.
In this section, we will discuss how to construct a simple store and how to perform simple manipulation of the data within it; how to create different views of a dataset using Chained stores; and finally, how hierarchical data can be stored using TreeStores.
To define a store, you must extend the Ext.data.Store class and configure it with a model class that it will hold a collection of. The following store definition shows a store containing a collection of user records:
Ext.define('BizDash.store.Users', {
extend: 'Ext.data.Store',
model: 'BizDash.model.User'
});