Rank: Newbie Groups: Member
Joined: 7/3/2008 Posts: 9
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Would you please give me a detailed documentation about the difference between CallBack and CallBackPanel Control ? I am successfully using CallBackPanel Control, but I do not know how to use CallBack control. I tried placing this control and added some triggers but nothing happens.
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Rank: Administration Groups: Administration
Joined: 5/27/2007 Posts: 24,221
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Hi,
The biggest difference between CallbackPanel and Callback control is, CallbackPanel is container and Callback is not. Because of that CallbackPanel is able to update controls inside its boundary, and Callback can not. Thus CallbackPanel is often used to update UI, the CallbackPanel is also triggered by triggers.
Since Callback control does not have any UI, it does not update any UI either. Nor does it use triggers. In short, it has direction relation with any UI elements. In order to use it, you will need to call eo_Callback JavaScript function to call it. So basically it provides you a JavaScript AJAX engine for you to call your server side code.
Since all features provided by the Callback control can also be found on CallbackPanel control, in practice Callback control is rarely used, unless you specifically do not want to have any UI involved ---- but even that can be achieved with an empty CallbackPanel with nothing in it.
Hope this helps.
Thanks
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