392994 - Remove support for <input usemap> and <object usemap>

Status: NEW

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

Description

[Lachlan Hunt]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6

Image maps on <input type=image> are currently supported (see bug 31188).

The URL given above provides some details about a survey conducted by Hixie, which lists a few hundred pages that use image maps on inputs (many of which break in Firefox) and provides some statistics of its use.  Some additional analysis of those pages in the survey is provided here.

http://lists.w3.org/Archives/Public/public-html/2007Aug/0506.html

This should be removed for the following reasons:

1. IE and Safari do not support this.

2. Very few sites use this, and many that do function better in browsers that don't.

3. The insignificant portion of sites that do rely on this to some degree are already broken in IE, and are outweighed by those that depend on it not working.

4. As its currently implemented, it provides no functionality beyond that provided by <img usemap>.

5. HTML5 currently will not be including the usemap attribute on input elements.

6. It appears that the intended purpose of it in HTML4 was to provide an accessible alternative to server-side image maps for form submission. But since, as it's currently implemented, image maps on input elements do not provide form submission, no accessibility benefits are achieved.

7. No significant use cases for client site image map form submission exist which cannot already be provided using alternative techniques.

Reproducible: Always

Steps to Reproduce:
1. Go to some of the pages listed in survey
2. Locate the input elements that use usemap
3. Click the region covered by an <area>
4. The form should submit, but doesn't
5. Compare with a browser that doesn't support usemap on input
Actual Results:  
The <area> covering the input prevents the form submission and creates usability problems.

Expected Results:  
The forms should submit.

Comment 1

[Robert Burns]

This bug is incorrect. The bug is not the support for usemap. The bug is that with <input type='image' usemap='map'> Firefox does not properly submit the form. The proportion of pages that try to use this feature is very very very small (because each browser gets it wrong in one way or another).  However Firefox has the more serious bug in getting wrong by not submitting the form when the mapped image is clicked.

Comment 2

[Hixie (not reading bugmail)]

Point 2 being the main one here. We can get better compatibility with sites by dropping this.

Comment 3

[Robert Burns]

(In reply to comment #2)
> Point 2 being the main one here. We can get better compatibility with sites by
> dropping this.
> 

No, all that's required for compatibility is to submit the form.

Comment 4

[Robert Burns]

(In reply to comment #0) 
> The URL given above provides some details about a survey conducted by Hixie,
> which lists a few hundred pages that use image maps on inputs (many of which
> break in Firefox) and provides some statistics of its use.  Some additional
> analysis of those pages in the survey is provided here.
> 
> http://lists.w3.org/Archives/Public/public-html/2007Aug/0506.html

One thing to keep in mind is that this survey failed to look for all examples of <input type=image usemap=map>. In particular it neglected to sample the most common case where the image map inlucded areas that did not have href attributes set on them. This is more likely the way the image maps for <input type=image> would be used.
 
> 3. The insignificant portion of sites that do rely on this to some degree are
> already broken in IE, and are outweighed by those that depend on it not
> working.

The sites are not broken in IE. They submit properly. They just do not provide any of the usemap functionality in IE. In other words IE, is broken but in not as serious a way as Gecko.

> 4. As its currently implemented, it provides no functionality beyond that
> provided by <img usemap>.

yes, that's the bug. It doesn't work as a submit button the way <input type='image' is supposed to work>

> 5. HTML5 currently will not be including the usemap attribute on input
> elements.

HTML5 is not even at public working draft status yet. Still too soon to cite it.
 

Comment 5

[Jesse Ruderman]

See also bug 392997, about the failure to submit the form.

Comment 7

[Anne (:annevk)]

We should do this for the object element as well.

Comment 8

[kalyanshiva98]

willing to take this on if you can give me a little more context

Comment 9

[Olli Pettay [:smaug][[e-mail]] (vacation-ish -> Aug 1)]

https://searchfox.org/mozilla-central/search?q=public+nsImageLoadingContent&path=&case=false&regexp=false shows which elements inherit
imageloading content.
https://searchfox.org/mozilla-central/rev/014fe72eaba26dcf6082fb9bbaf208f97a38594e/dom/base/nsImageLoadingContent.cpp#1768,1770 should probably filter out the elements types for which we don't want to support usemap.
https://searchfox.org/mozilla-central/rev/014fe72eaba26dcf6082fb9bbaf208f97a38594e/dom/base/nsINode.h#764-767 and similar method could be probably useful.

And usemap usage from the elements it is not needed should be removed
https://searchfox.org/mozilla-central/search?q=%3A%3Ausemap&path=&case=false&regexp=false

Comment 11

[Jonathan Kingston [:jkt] he/him]

Attachment: Bug 392994 - Remove support for usemap for Object and Input elements. r?peterv

Comment 12

[Masatoshi Kimura [:emk]]

Is the analysis in comment #0 (16 years ago!) still valid? Caniuse says usemap on input/object is supported almost everywhere.

Comment 13

[Jonathan Kingston [:jkt] he/him]

Both are marked as obsolete in the spec https://html.spec.whatwg.org/multipage/obsolete.html#dom-object-usemap and neither work in Chrome and Safari. (I couldn't get <object> to work either in Firefox despite the support)

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b387df97a255
Remove support for usemap for Object and Input elements. r=peterv

Comment 15

[Natalia Csoregi [:nataliaCs]]

Backed out for causing failures on test_interactive_content_in_label.html

• backout: https://hg.mozilla.org/integration/autoland/rev/144c26caf658d56a61dc0091fe77e093f4d03371
• push: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&revision=b387df97a255c76bfc071ad52892e97cbe14403f&selectedTaskRun=PIG0UhM4T7WmDeUkP8Q9_w.0
• failure log: https://treeherder.mozilla.org/logviewer?job_id=423104712&repo=autoland&lineNumber=2636

[task 2023-07-19T05:56:49.649Z] 05:56:49     INFO -  TEST-PASS | dom/html/test/forms/test_interactive_content_in_label.html | mouse click on interactive content LABEL shouldn't dispatch event to label target
[task 2023-07-19T05:56:49.649Z] 05:56:49     INFO -  Buffered messages finished
[task 2023-07-19T05:56:49.649Z] 05:56:49  WARNING -  TEST-UNEXPECTED-FAIL | dom/html/test/forms/test_interactive_content_in_label.html | mouse click on interactive content OBJECT shouldn't dispatch event to label target - got true, expected false
[task 2023-07-19T05:56:49.649Z] 05:56:49     INFO -      SimpleTest.is@SimpleTest/SimpleTest.js:507:14
[task 2023-07-19T05:56:49.650Z] 05:56:49     INFO -      @dom/html/test/forms/test_interactive_content_in_label.html:82:5
[task 2023-07-19T05:56:49.650Z] 05:56:49     INFO -  TEST-PASS | dom/html/test/forms/test_interactive_content_in_label.html | mouse click on interactive content SELECT shouldn't dispatch event to label target

Comment 16

[Natalia Csoregi [:nataliaCs]]

• Backout merged to mozilla-central: https://hg.mozilla.org/mozilla-central/rev/144c26caf658d56a61dc0091fe77e093f4d03371

Comment 17

[BugBot [:suhaib / :marco/ :calixte]]

This good-first-bug hasn't had any activity for 2 months, it is automatically unassigned.
For more information, please visit BugBot documentation.

Comment 19

[BugBot [:suhaib / :marco/ :calixte]]

Clear a needinfo that is pending on an inactive user.

Inactive users most likely will not respond; if the missing information is essential and cannot be collected another way, the bug maybe should be closed as INCOMPLETE.

For more information, please visit BugBot documentation.