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Bug 22745 - [Explainer]: Use case for registering a type extension of an unknown element
Summary: [Explainer]: Use case for registering a type extension of an unknown element
Status: RESOLVED WONTFIX
Alias: None
Product: WebAppsWG
Classification: Unclassified
Component: HISTORICAL - Component Model (show other bugs)
Version: unspecified
Hardware: PC Linux
: P2 normal
Target Milestone: ---
Assignee: Dimitri Glazkov
QA Contact: public-webapps-bugzilla
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: 14949
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Reported: 2013-07-21 00:52 UTC by Dominic Cooney
Modified: 2014-01-20 02:47 UTC (History)
1 user (show)

See Also:

Attachments

Description Dominic Cooney 2013-07-21 00:52:31 UTC 
Here is an interesting use case for the 'extends' attribute: polyfilling a HTML element that is not implemented yet by registering a type extension of an unknown element

For example, say a UA implements Custom Elements but not <dialog>. It is neat that Custom Elements can be used to polyfill <dialog> with <dialog is="polyfill-dialog">.

This gives polyfills a very smooth upgrade path--they can detect if there's a native HTMLDialogElement and flip to being a no-op.

Maybe the Explainer could incorporate this use case; WDYT?
Comment 1 Dimitri Glazkov 2013-08-07 20:45:39 UTC 
Sounds good.
Comment 2 Dominic Cooney 2014-01-20 02:47:10 UTC 
I'm going to punt on this. I think it's interesting, but I don't think it's a primary use case.