So normally the page of data that is exposed to the extension is defined in the definition.xml file through a pageheight value. If no value is present it will default to 20 rows I believe.
Now, you can also control this and which pages to fetch. This is some psuedo code.
//Set your initial PageSize.
this.Data.SetPagesizeY( 2000 );
//cache the Data class.
var data = this.Data
//Click the extension and call SetOffset(page). This should cause a re-render of the extension.
$(this.Element).on('click', function() {
data.SetOffset({ y: data.PageOffset.y + data.PageSize.y, x: data.PageOffset.x });
})
Attached is also a sample extension which demonstrates paging.
