Submit form action

Question

I need to do some validate before form submit.

I can not modify the html code and existing js (the only way is to add new js file).

I tried this one:

$('form').submit(function() {
    alert("check");
    return false;
});

but it does not call.

I tried this one too:

$(document).on('submit', 'form', function(e) {
    alert("check");
    return false;
});

it calls correctly but only for alert().

How is it possible to set false for disable form submit when my checkFunction() returns false?

@Passerby I tried to add `e.preventDefault();` before the `alert()` but it doesnt work (form is submitted). — karl person, Oct 16 '18 at 10:43
@Arvind the function `checkFunction()` is not called yet. It doesnt work for const values `true` and `false` (I mean that form is submited). — karl person, Oct 16 '18 at 10:44
You could try removing any existing event handlers before adding your own, eg: `$('form').off('submit').on('submit', function() {...` — Rory McCrossan, Oct 16 '18 at 11:04
if you have multiple forms on the same page then give `id` to particular form — Rudra, Oct 16 '18 at 11:24
@RoryMcCrossan I added `.off('submi')` but it doesnt work (form is submitted anyway) — karl person, Oct 16 '18 at 11:36

score 1 · Answer 1 · answered Oct 16 '18 at 11:08

1

You can use jquery validation plugin for validation before form submit. It is better for that. You can refer below link:

answered Oct 16 '18 at 11:08

Kartik Bhalala

score 0 · Answer 2 · edited Oct 16 '18 at 10:44

0

e.preventDefault should help you there, because it is preventing the default behavior of the submit.

$(document).on('submit', 'form', function(e) {
  e.preventDefault();
  alert("check");
  return false;
});

edited Oct 16 '18 at 10:44

Rory McCrossan

answered Oct 16 '18 at 10:42

Frederik

`return false` will perform the same action (as well as `stopPropagation`), so if that didn't work, this is unlikely to make a difference. – Rory McCrossan Oct 16 '18 at 10:44
I tried it `e.preventDefault()` but it does not work. – karl person Oct 16 '18 at 10:45
@RoryMcCrossan Do you have any idea what could be a solution? – karl person Oct 16 '18 at 10:49
@karlperson May this helps you: https://stackoverflow.com/questions/3350247/how-to-prevent-form-from-being-submitted – Frederik Oct 16 '18 at 10:50
With such little information in the question it's impossible to determine the problem. – Rory McCrossan Oct 16 '18 at 10:52
@RoryMcCrossan what kind of information is necessary to detect the problem? – karl person Oct 16 '18 at 11:03
An example which shows the behaviour, so we'd need to see the HTML as well as any other events which are put on the element by the external JS file. – Rory McCrossan Oct 16 '18 at 11:04

2 Answers2