jQuery: form.submit(fn) does not work with Asp.net?

Question

I am trying to attach an event handler to form.submit on asp.net rendered pages with no success. I want to intercept every postback, and doc. says that I should be able. Am I doing something wrong?

$(document).ready(function() {
    $("form").submit(function() {
            alert('Form submit');
            debugger;
    });
});

Answer 1

asp.net webforms are generally enveloped in only one big form (hence the term web forms).

if I'm not mistaken, all links and submit buttons call __doPostBack manually, so it bypasses the calling form submit and delegates that responsibility to the __doPostBack function.

you would probably need to overwrite this function.

<script type="text/javascript"> 
//<![CDATA[
var theForm = document.forms['aspnetForm'];
if (!theForm) {
    theForm = document.aspnetForm;
}
function __doPostBack(eventTarget, eventArgument) {
    if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
        theForm.__EVENTTARGET.value = eventTarget;
        theForm.__EVENTARGUMENT.value = eventArgument;
        theForm.submit();
    }
}
//]]>
</script> 

though I'm trying to understand your "debugger;" line in your function. perhaps it should be this?

$(document).ready(function() {
    $("form").submit(function() {
            alert('Form submit');
    });
});