When using other AJAX frameworks, you need to set some kind of AJAX triggers in order to define the AJAX behavior of the page (which controls initiate AJAX requests and which controls are respectively updated). This approach, however, presents a serious inconvenience because the AJAX relations are defined in a way that's reverse to the users' natural interaction with the application interface.
Consider we have the following AJAX relation:
- When the calendar is clicked the e-mail list and the message body need to be updated
This represents the actual sequence in which the user will interact with the application - he/she will click a day on the calendar and as a result the e-mail list and the message body will be updated.
However, when using triggers you will have to define this scenario in the opposite way - which element has to be updated as a resuit of another element being clicked. So for the above AJAX relation you will have to set 2 triggers.
"Message Body" ajax Panel - Trigger 1: The message body needs to be updated when the calendar is clicked
"E-mail list" ajax Panel - Trigger 2: The e-mail list needs to be updated when the calendar is clicked
As you can see, the combination of 2 triggers define one AJAX relation. Moreover, they are defined in the reverse direction, which can be a significant challenge when AJAX-enabling complex real-life applications like the Telerik HelpDesk sample, which will probably need 20+ ajax Panels and 50+ triggers.
The Telerik RadAjax framework offers a much more intuitive way for setting AJAX relations, which follows the users' natural interaction with the application interface.
Consider we have to implement the same AJAX relation:
- When the calendar is clicked the e-mail list and the message body need to be updated
To do this we need to open the AJAX Manager dialog and use the checkboxes to define the following:
Set the calendar (Calendar1 control) as a control that will initiate AJAX requests
Set the e-mail list (EmailGrid control) and the message body (MessageBody control) as controls that need to be updated after the respective AJAX request (in our case initiated by the calendar)
This approach is much more convenient and gives you an "at-a-glance" picture of the various AJAX relations and the elements that comprise them. To extract this information otherwise would require that you go over all Triggers and draw something like a "Trigger diagram".
Last but not least the Telerik RadAjax framework offers a completely Codeless Development experience.
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