Adding custom client-side onClick handler with client-side validator controls

[Zoe Hart]

I know that I can use a control's Attributes collection to specify
client-side event handlers. I want to add a simple javascript function to
pop up a confirmation message for a command button. The problem is that the
page uses several client-side field validators so ASP.NET is already using
the control's onClick event to call the validation logic. Is it possible to
have a custom client-side handler when you're using the validator controls?
The only way I've managed it in the past is to turn off client-side
validation for the page, but I'd rather not do that in this situation where
I'm making more extensive use of the client-side validators.

Thanks,
Zoe

 

[Scott Wisniewski]

The key is to add your code to the onClick event handler. You can acheive
this using the "new Function" syntax in JavaScript. This is an example of
something called a "higher order function" which is a function whose return
value is yet another function. Here is the JavaScript that will enable this:

function AddEventHandler (func, body) {
if (func != null)
return new Function(body + ';' + func.toString());
else
return new Function(body);
}

function AddOnClickEventHandler (ctrl, body) {
ctrl.onclick = AddEventHandler(ctrl.onclick, body);
}