As you know that, FileUpload Control is not supported by [url removed, login to view] AJAX Update Panel. We need to use Triggers to make the FileUpload work within Update Panel.
Now, I have an [url removed, login to view] Composite Server Control which has FileUplod in it. So, I want that, when an user place my control within an AJAX update panel, the control will check the PARENT property of it and check if it is an AJAX Update Panel, programatcally add Trigger for this control so that FileUpload works within this Update Panel without my control user worry about changing any code in their ASPX page. Everything should be done within the Server Control and I want my user only to drag and drop the contol into their AJAX Update panel and ready to go. PLEASE NOTE : THIS IS THE MOST IMPORTANT INSTRUCTION TO BE FOLLOWED : "NO CODE FIX FROM OUTSIDE THE CONTROL... NOTHING SHOULD BE INSTRUCTED TO CHANGE IN ASPX PAGE". PURELY PROGRAMATIC SOLUTION REQUIRED THAT WILL BE EXECUTED FROM SERVER CONTROL.
I dont need asynchronous file upload functionality but adding trigger will atleast allow this control to work within UpdatePanel even though it will be synchronous post, still OK for me.
Please note, The code should be smart to dedect if any of its parent or parent's parent is AJAX Update Panel. If so only then add trigger otherwise it should not throw any Exception. That means, If I use this control without AJAX Update Panel, it should work properly, it should not only work for Update Panel.