Do something javascript before asp.net anypostback

Question

I wanna do something in javascript before page goes for post back.

How to run a javascript function before any asp.net postback?

$('form').submit(function () {
      alert('hello');
});

It doesn't work... :(

score 17 · Accepted Answer · edited Jan 17 '13 at 07:59

17

I find the way, in the asp.net forums and it was a some code in codebehind.

Just add this to your Page_Load event handler, changing the javaScript string to what you want to happen.

string scriptKey = "OnSubmitScript";
string javaScript = "alert('RegisterOnSubmitStatement fired');";
this.ClientScript.RegisterOnSubmitStatement(this.GetType(), scriptKey, javaScript);

edited Jan 17 '13 at 07:59

lmcanavals

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answered Mar 14 '12 at 05:47

Emech

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1

+1 I know how old this is, but thank you so much! It helped me a lot. – user3439065 Jul 15 '14 at 08:56

score 5 · Answer 2 · answered Mar 11 '12 at 12:17

5

If you want to do something client-side before asp's postback, try using the OnClientClick attribute of the asp:button, eg:

<asp:Button OnClick="submit" OnClientClick="myPrePostbackFunction()" Text="Submit" runat="server" ... />

answered Mar 11 '12 at 12:17

graphicdivine

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i know that, but i have lots of asp element on page , i want to do this code before any postback, not for a special button or element – Emech Mar 11 '12 at 12:19

score 2 · Answer 3 · answered Mar 11 '12 at 12:31

2

try:

$('form').submit(function () {
    return confirm('you sure?');
});

The form won't be submitted unless you return true and before that you can do all you want. It doesn't have to be a confirm() call of course.

answered Mar 11 '12 at 12:31

lmcanavals

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Quite odd, what browser are you using to test? – lmcanavals Mar 11 '12 at 21:55

score 1 · Answer 4 · answered Oct 27 '21 at 11:38

1

In year 2021, I'm completey getting rid of jQuery. To do this, I add to my page javascript:

document.forms[0].addEventListener('submit', e => {
if (conditionPreventingPostBack) {
    e.preventDefault();
    return false;
    }
});

answered Oct 27 '21 at 11:38

davidthegrey

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score 0 · Answer 5 · answered Mar 11 '12 at 14:11

try this?

    <form name="someform">
    <input type="submit" value="" />
</form>
<script type="text/javascript">
document.someform.onsubmit = function  ( e ) {
    e = e|| window.event;
    if ( !confirm ( "sure?") ){
        e.returnValue ? ( e.returnValue = false ):  e.preventDefault();
    }
}
// then jquery version
$("form").bind("submit", function  ( e ) {
    if ( !confirm ( "sure?" ) ){
        e.preventDefault();
    }
})
</script>

Do something javascript before asp.net anypostback

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