Windows® 8.1 Apps with HTML5 and JavaScript Unleashed

Creating the Data Source Class

The easiest way to create a custom data source is to derive a new class from the base VirtualizedDataSource class. For example, you can use the following code to create a new data source named MyDataSource:

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var MyDataSource = WinJS.Class.derive(    WinJS.UI.VirtualizedDataSource,    // Constructor    function () {        this._adapter = new MyDataAdapter();        this._baseDataSourceConstructor(this._adapter);    });

In the preceding code, two arguments are passed to the WinJS.Class.derive() method to create the new MyDataSource class: a base class (WinJS.UI.VirtualizedDataSource) and a constructor for the new class.

In the constructor for your derived VirtualizedDataSource class, ...