642753 - Allow `oninput` feature detection

Status: RESOLVED DUPLICATE of bug 414853

(Core :: DOM: Core & HTML, defect)

Description

[Mathias Bynens]

User-Agent:       Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_6) AppleWebKit/534.25 (KHTML, like Gecko) Chrome/12.0.706.0 Safari/534.25
Build Identifier: 

Firefox has supported the `oninput` event at least since version 2. However, for some reason the following evaluates as `false`:

    'oninput' in document.createElement('input'); // false

I would expect 'oninput' in document.createElement('input') to return true, since the oninput event and the attribute are supported.

There is still a way to feature test for oninput support in Firefox, but it involves using the event API to create an input and fake a keypress to see if oninput fires, which is more complicated than it should be. (See http://blog.danielfriesen.name/2010/02/16/html5-browser-maze-oninput-support/ for more details.)

Reproducible: Always

Steps to Reproduce:
1. Open data:text/html,<script>alert('oninput' in document.createElement('input')?'PASS':'FAIL')</script>
Actual Results:  
FAIL

Expected Results:  
Firefox should alert “PASS” because it supports `oninput`. Seems like Firefox is being modest.

Comment 1

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

This is bug 414853. Maybe we want to special case?

Comment 2

[Olli Pettay [:smaug][[e-mail]]]

I don't understand why you need a fake keypress.

javascript:document.documentElement.oninput = function() {alert("input");}; var e = document.createEvent("Event");e.initEvent("input", false, false); document.documentElement.dispatchEvent(e); void(0)

Comment 3

[Mounir Lamouri (:mounir)]

Isn't that bug a dup of bug 414853?

Comment 5

[Diego Perini]

(In reply to comment #2)
> I don't understand why you need a fake keypress.
> 
> javascript:document.documentElement.oninput = function() {alert("input");}; var
> e = document.createEvent("Event");e.initEvent("input", false, false);
> document.documentElement.dispatchEvent(e); void(0)

I cannot make that test work (FF3.6.15 Mac).

Should DOM2 dispatchEvent fire DOM0 events ?

Are "input" events valid for any element or just focusable elements ?

Comment 6

[Olli Pettay [:smaug][[e-mail]]]

element.oninput was added for FF4, Bug 618948

If you want to test oninput as attribute you could do
javascript: var el = document.createElement("div"); el.setAttribute("oninput", "alert('input')"); var e = document.createEvent("Events"); e.initEvent("input", false, false); el.dispatchEvent(e); void(0);

And yes, oninput should work in all HTMLElements.
http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#handler-oninput

Comment 7

[Diego Perini]

(In reply to comment #6)
> element.oninput was added for FF4, Bug 618948
> 
> If you want to test oninput as attribute you could do
> javascript: var el = document.createElement("div"); el.setAttribute("oninput",
> "alert('input')"); var e = document.createEvent("Events"); e.initEvent("input",
> false, false); el.dispatchEvent(e); void(0);
> 
> And yes, oninput should work in all HTMLElements.
> http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#handler-oninput

Thank you for the tips and the updates.

Still looking at this description:

   http://dev.w3.org/html5/spec/Overview.html#event-input-input

"When the input event applies, any time the user causes the element's [value] to change, ..."

I don't see how "element's value" can change for elements which are not form controls.

Is it just a discrepancy or did I get that wrong ?

Comment 8

[Olli Pettay [:smaug][[e-mail]]]

input event bubbles, so any parent node of <input> or <textarea> element
may get it.