Determine which element submitted a form from within onsubmit

Question

Is there a way to determine which element submitted a form from within an onsubmit handler? Trying to write a generic handler that knows which element was clicked. For example, given this form:

<form onsubmit="onSubmitHandler">
    <input type="submit" name="submit1" />
    <input type="submit" name="submit2" />
</form>

How can I determine inside the onSubmitHandler which submit button was clicked? I tried event.target/event.srcElement, but that gives the form, not the actual submit button.

Update: I'm writing a generic control here, so it has no idea what's on the form. The solution needs to work without knowing and changing the html of the form. My fallback is walking the DOM to find all buttons that could cause a submit, but I'd like to avoid that.

Answer 1

An alternative solution would be to move the event trigger from the form's submit event, to the submit element's onclick event, as such:

<form name='form1'>  
    <input type="submit" name="submit1" onclick="onSubmitHandler"/>
    <input type="submit" name="submit2" onclick="onSubmitHandler"/>
</form>

In your handler function you can determine the submitting element simply by inspecting the event target's name, and if you need access to the form's information or other elements, you can get this from the submit elements "form" attribute.

Answer 2

I would not use a standard submit button-type.

Make the submit function take an extra argument which represents the element that submitted it, and the button would have an onclick that sends this as the parameter:

<input type="button" onclick="submitHandler(this)">

Answer 3

My fallback is walking the DOM to find all buttons that could cause a submit, but I'd like to avoid that.

...and adding click listeners to them to store the ‘last clicked’ button which is then read by the submit listener, right?

I can't think of any other way, sorry.

Answer 4

This solution works in Firefox. I haven't checked it in other compliant browsers or IE.
I'm not too hopeful for IE, you'd have to look into it and post your results.

<form id="myForm">
    <input type="submit">
    <input type="submit">
</form>

_

document.getElementById('myForm').addEventListener( 'submit', function( e ){
    e.preventDefault();
    e.explicitOriginalTarget.style.background = 'red';
}, false );