In Server Centric Development or UpdatePanel model, the developer creates the pages with regular Controls wrapped in one or more UpdatePanels. This approach adds extra overhead in the regular page life cycle, which is required to generate the changes of the updated part of the page. From the developer point of view, it is rather easy and takes less time to implement Ajax with this model, compared to Client Centric Development.

On the other hand, in the Client Centric Development model, the developer calls Web Services, which return the data. The data is quite small compared to the Server Centric Development Model, as it doesn't contain the HTML that the UpdatePanel returns. The refreshing logic resides in JavaScript code on the client side, and thus offloads the web server from any rendering responsibility. This makes it possible to create more scalable web applications compared to the Server Centric Model. However, implementing this approach takes more time, as the developer does not get the various benefits of the Server Centric Development Model; such as a rich set of Controls, Design time support, familiar APIs and so on.

The Ajax Control Toolkit contains some valuable Controls, but it does not contain Controls that work with data. Currently there is no way to work with the data Controls such as the GridView, DataList or Repeater in the Client Centric Development model. The reason is that these Controls do not have any object model on the client side, which we can leverage with JavaScript. In this article, I will show how to create a simple yet powerful data-bound templated Repeater with ASP.NET AJAX. This Control exposes the same object model on the client side which developers are familiar with from the server side object.