The best fit for your project - Telerik's ASP.NET AJAX ComboBox or AutoCompleteBox?

We have always tried to listen to our customers' feedback and act accordingly in order to provide the best service possible and deliver more than expected:). A common feature request that we are receiving these days is to provide token input that has the same functionality as the one that can be found in Facebook, for example. On a side note, we have noticed that every now and then there are customers, who are having a hard time configuring our RadComboBox in load on demand/autocomplete scenarios. Then an idea came to our minds. - “Hey, why don’t you extract the auto complete functionality from the ComboBox in a new, dedicated control and couple it with a token mode. The new control should be straightforward to use, have lightweight rendering and be easy to bind against WebServices/Declarative Data Sources. ”

Having this idea in mind, we put all the know-how we have gathered from the ComboBox into the newly born RadAutoCompleteBox, which is targeted to fill the gap between the ComboBox and the requests for tokens input/straightforward autocomplete. In the following lines I will highlight the core AutoCompleteBox features and then compare and contrast it with the ComboBox in order to find out which one is the best fit for a given scenario.

Meet the AutoCompleteBox

As its name suggest, the AutoCompleteBox is a text box with … auto completion. It is designed to take that burden from the combo and make it straightforward for developers to implement auto completion in their scenarios. Here are the quick facts:

1. The component is designed to be fast and lightweight. It renders semantic HTML and performs the search on the server for maximum performance.
2. When it comes to binding, the developer can choose among web services – WCF/OData/PageMethods or a Callback binding to a variety of data sources.  
3. Two visual modes – Token or Text. The difference between the two modes is mainly visual, with one exception. In token mode it is currently not possible to edit already selected token. However, we have already gathered a feature request for token editing, so you can expect to see the feature included in the Q3 release.
   
4. Client and server-side templates – The AutoCompleteBox is designed from the very beginning to make use of client templates, which are the natural choice in web-service scenarios. The templates currently apply to the items in the drop down, however, from Q3 2012 we will add templates for tokens as well.

More thorough explanation of each of these features can be found in the online help here.

AutoCompleteBox vs ComboBox

We realize that adding a new control that resembles RadComboBox so closely might be confusing; this is why I will try to emphasize on the strong and weak parts of both controls. Let’s take a look at the comparison table below:

I hope that the above table sheds some light on what are the main differences between the two components. In short, AutoCompleteBox is designed to take away the burden of auto completion from the combo and is now the natural choice in search box with load on demand scenarios and everything that has to do with auto completion. On the other hand, the ComboBox is still the preferred choice for all other drop down related scenarios.

This is it in short. We are now gathering feedback and feature requests so if you have anything to share don’t hesitate to drop us a line. :)