Not a bad idea, but the 'submit' event uses Event currently, which doesn't have a relatedTarget, so this would have to involve a new Event interface type.

another solution could be referencing the submit button in some property of the HTMLFormElement interface, in the same way document.activeElement works

something like myform.submittedBy

imho not very cool though

Yeah doing it on the event seems better.

another solution could be include relatedTarget in the Event interface

anyway...
I should have written a best use-case for this feature request, so here it is

<button name="action" value="listAll">List All Selected</button>
<button name="action" value="deleteAll">Delete All Selected</button>

myform.addEventListener("submit", function(event){

       // [I'm guessing] FormData doesn't include buttons name/value pairs:

       var fd = new FormData(this);

       if(event.relatedTarget)
              fd.append(event.relatedTarget.name, event.relatedTarget.value);
       else
              fd.append("action", "listAll");

       event.preventDefault();

       var xhr = ...;
       // ...
       xhr.send(fd);

}, false);

Are there any browser vendors interested in implementing something like this?


(In the meantime you can work around the lack of this feature by doing this:

 <form onclick="if (event.target.type == 'submit') this._button = event.target">

...on the <form> element. This sets form._button to the submit button in time for the onsubmit handler.

Actually we can't rely on anything for that. Listen clicks on `input[type=submit]` and `button[type=submit]`, use `document.activeElement`, etc.
Mozilla provide a specific property on the submission event (and few others): `event.explicitOriginalTarget` to provide a "related" target.
In http://www.w3.org/html/wg/drafts/html/master/forms.html#form-submission-algorithm there is a mention of a "submitter".

Here there is a talk about it: http://discourse.specifiction.org/t/extend-submit-events-add-the-button-element-that-triggered-the-submit/406

I don't understand. Why doesn't the proposed markup work? I tried it and it seemed to work fine on Chrome and Firefox at least. It even works with implicit submission (where you hit enter in a text field and it picks the default submit button).

http://software.hixie.ch/utilities/js/live-dom-viewer/saved/3192

This don't work:

- the submitter is not only `[type=submit]` but also: `input[type=submit]`, `input[type=image]`, `button[type=submit]`
- the event target can be a descendant of a button: `<button><span>Submit</span></button>`
- this works for ["authentic click activation"][1] (direct click or key stroke) and ["synthetic click activation"][2] (click via `element.click()` or `element.dispatchEvent(new MouseEvent(...))`) but not ["Implicit submission"][3] (hitting enter or space key, depends implementation, when an other form field focused)

This will work on some cases, but not all.


[1]: http://www.w3.org/html/wg/drafts/html/master/editing.html#run-authentic-click-activation-steps
[2]: http://www.w3.org/html/wg/drafts/html/master/editing.html#run-synthetic-click-activation-steps
[3]: http://www.w3.org/html/wg/drafts/html/master/forms.html#implicit-submission

The example can be easily updated to work with type=image or nested content in <button>s if you need that. It already works for implicit submission.

Here's an example that does everything you mentioned:
   http://software.hixie.ch/utilities/js/live-dom-viewer/?saved=3199


Note that dispatchEvent(new MouseEvent()) is not a valid way of submitting a form. It should have no effect; it has some effect in some browsers due to a bug, which we are trying to fix.

BTW the links you are giving to the spec are to the forked out-of-date version of the spec. The spec I edit is at: http://html.spec.whatwg.org/multipage/

OK! I miss one important thing. In [synthetic click activation steps][1] there is:
"4. Fire a click event at the element".
That means, for browsers that implement HTML5, we can listen implicit submission with click events.

I tried your example and that work correctly on:

- Safari 7.1
- Firefox 33.0
- Chrome 38.0
- Safari Mobile 7.2
- Chrome iOS 37

But not on IE 9 (I got an error "error: Unable to get value of the property 'value': object is null or undefined on line 1", but I don't have the time to found why click don't work).

Thanks

[1]: https://html.spec.whatwg.org/multipage/interaction.html#run-synthetic-click-activation-steps

Well I presume that's because IE9 doesn't implement the specs properly. Does it work in more recent IEs?

Yes, I confirm that works in IE10

Cool, ok, thanks.

Given how simple it is to achieve this, and how widely supported it is (especially compared to a new API, which nobody implements), maybe this feature request is something we shouldn't add to the platform.

Closing per comment 13. If there's a compelling reason why the simple script above isn't a satisfactory solution, please reopen the bug. Thanks!