load on demand wcf client side tips and tricks required for data integrity

[Mac P]

Hello,
I want to avail the functionality to load on demand on the dropdown arrow click and just able to select the entire list item text because list item value is the id that is to be stored in database. AFter going through the documentation i realised that load on demand doesnt allow to select the entire list item text. So is there a trick or tip regarding how to avail this functionality as i dont want to display the text other than what is listed in dropdown. If there is trick that will allow to search on demand than that will be great but i am content if the first part of requirement is achieved.

Inshort
1) Populate combo box on load on demand
2) Allow entire combo box item to be selected. That way i can get id from selected value
3) When in edit mode prefill the combo box will the item that was saved to database.

Any help is greatly appreciated.
mac

[Simon]

Hello Mac P,

You could achieve the first and second points from your requirements by doing the following:

• Set the EnableLoadOnDemand property of the RadComboBox to false.
• Handle the server-side ItemsRequested event and bind/load the Items in the RCB there.
• Handle the client-side DropDownOpening event in this way:

  function onDropDownOpening(sender) {
      if (sender.get_items().get_count() == 0)
          sender.requestItems("", false);
  }

Finally, if you want to pre-load the Items in the RCB in a certain moment you could execute the same code as in the ItemsRequested event handler on the server.

I hope this helps.

Sincerely yours,
Simon
the Telerik team

[Mac P]

Thanks for your response. I dont want to bind it on server side as i dont want to do any postbacks. Binding will be done on client side using WCF.

Is it possible to do it on client side? Will it preserve changes to server when i submit the request.?

Regards
Mac

[Simon]

Hello Mac P,

Yes, you could Load On Demand through a WCF service as you would do with a normal Web Service. Please see this demo for a complete sample and this help article for a tutorial showing how to setup the service and the RadComboBox.

The changes, however, will not preserve after a postback and this is true for every Load On Demand approach.

I hope this helps.

Greetings,
Simon
the Telerik team