Re: [WICG/webcomponents] Custom 'void' or self-closing elements (HTML parser changes) (#624)

> This would require that custom element definitions happen in a script tag before any custom elements are encountered during parsing

Parser blocking on scripts is always fairly expensive, this is why new features (e.g. module scripts) don't allow it, and there's even features in the works specifically to disable the behaviour entirely (e.g. [feature policy](https://chromestatus.com/feature/6218263637786624)).

Anything that requires new sync scripts is almost certainly not going to gain any implementer interest.

A warning *after the fact* might be viable, as browsers could simply set a bit while parsing and then check and warn during upgrade.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/WICG/webcomponents/issues/624#issuecomment-770160379