Update for link element's disabled attribute being added back #4323
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At some point, the link element's disabled attribute was removed from the spec. It has since been restored but was not linked to the stylesheet's disabled attribute. In whatwg/html#3840, the two are being revised to reflect one another. This BCD update adds data to indicate this.
html/elements/link.json
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| @@ -146,19 +146,23 @@ | |||
| "__compat": { | |||
| "support": { | |||
| "chrome": { | |||
| "version_added": false | |||
| "version_added": true, | |||
| "notes": "Chrome does not include stylesheets which have the HTML <code>disabled</code> attribute in <code>document.styleSheets</code>." | |||
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This is wrong: Firefox (and the proposed spec) won't include them. Chrome and WebKit don't include them if they're added to the document with the disabled attribute, but they do if the attribute is removed dynamically (that's silly).
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I could have sworn that this note essentially says what I had understood the situation to be on Chrome, but apparently I'm wrong there. I seem to recall seeing someone say that Chrome needed a patch to match this change to the spec, but now cannot find that reference. Do you know what that change would be, @emilio?
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Yeah, the chrome behavior is a bit hilarious and hard to reason about.
It won't be included in document.styleSheets if by the time it's added to the document it has the disabled attribute. That is to say, the following:
<!doctype html>
<link rel="stylesheet" href="foo" disabled>would yield no stylesheet in document.stylesheets.
However, this:
<!doctype html>
<link rel="stylesheet" href="foo" onload="this.setAttribute('disabled', 'true')">Would yield a stylesheet in document.styleSheets. shrug :)
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@emilio - So if I understand you correctly, you're right about Chrome not making sense. Basically, what I gather is that
- If the page doesn't have the
disabledflag set on<link>when it is first loaded, the stylesheet is included indocument.styleSheets. It stays in that list no matter what you do from then on. - If the
disabledflag is set on a<link>when the HTML is loaded, the stylesheet is not added todocument.styleSheets, and nothing you do causes it to be added. Somehow the stylesheet is applied without being listed. Creepy.
Otherwise, I think the behavior is about the same. But this is weird and tricky stuff. :)
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(1) is right. Re. (2) I would've sworn that removing disabled puts the link back in document.styleSheets, and from then on it cannot be removed anymore. But I could be misremembering.
But yeah, it doesn't make any sense, thus the issue.
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My testing seems to show (2) to be true. I am going to leave it as it is now and ask @jpmedley to review.
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So you got this from manual testing?
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@jpmedley - Yeah, manual testing. If I'm wrong then I'm wrong. It certainly wouldn't be the first time. I'd have to pore over my code to understand why, but at this point I'd rather take your word for it. Let me know.
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I'm satisfied that your understanding is correct. Change as you see fit.
html/elements/link.json
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| }, | ||
| "edge": { | ||
| "version_added": true | ||
| }, | ||
| "firefox": { | ||
| "version_added": false | ||
| "version_added": "68", | ||
| "notes": "Prior to Firefox 68, the HTML <code>disabled</code> attribute worked but could not be changed using JavaScript code." |
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This is also wrong. It didn't work either way, the disabled element attribute did nothing. The disabled WebIDL attribute just reflected the disabled state of the stylesheet, if any.
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You're right -- I misread my test code's output. I'll remove the notes here.
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@jpmedley - Can you please take a look at this comment above and see if you can determine if that's accurate. Then I can finalize the doc update and this PR and get them in. |
Done. See conversation above. |
inclusive of all Blink-based products. Replaced old and incomplete note on the Android WebView entry.
At some point, the link element's disabled attribute was removed
from the spec. It has since been restored but was not linked to
the stylesheet's disabled attribute.
In whatwg/html#3840, the two are being
revised to reflect one another. This BCD update adds data to
indicate this.
Firefox bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1281135
Firefox intent to implement: https://groups.google.com/forum/#!topic/mozilla.dev.platform/BdgNaChHnpY