Bug 195403 - Customized built-in elements aren't supported
Summary: Customized built-in elements aren't supported
Status: RESOLVED DUPLICATE of bug 182671
Alias: None
Product: WebKit
Classification: Unclassified
Component: DOM (show other bugs)
Version: WebKit Nightly Build
Hardware: All All
: P2 Major
Assignee: Nobody
Keywords: HTML5
Depends on:
Reported: 2019-03-07 00:25 PST by Andreas Deuschlinger
Modified: 2019-12-27 09:03 PST (History)
4 users (show)

See Also:


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Description Andreas Deuschlinger 2019-03-07 00:25:42 PST
The HTML Living Standard for Custom Elements specifies support to extend existing built-in elements, by:
- the `is="my-button"` attribute
- the `document.createElement('button', { is: 'my-button' })` second argument


The Webkit Status page gives incorrect information claiming that Custom Elements V1 are supported,
though in fact only "autonomous custom elements" are supported.

Caniuse informs about this incomplete implementation correctly:
Comment 1 arjunyel+webkit.bugzilla 2019-03-08 11:53:01 PST
Previous discussion about this on Github https://github.com/w3c/webcomponents/issues/509#issuecomment-222860736
Comment 2 Ryosuke Niwa 2019-03-09 18:24:45 PST
Our position has been that this feature shouldn't exist in the spec in the first place. I really don't understand how we ended up allowing Google to keep this feature in the HTML5 spec despite of our repeated objections.

*** This bug has been marked as a duplicate of bug 182671 ***
Comment 3 Andreas Deuschlinger 2019-03-12 03:14:19 PDT
Thanks  a lot for your quick feedback:)

Meanwhile i came across element behaviors a the suggested has attributes:

Which is what I would really need:) But gies beyond this ticket...