[webcomponents]: Custom elements no longer automagically create shadow trees


As of https://dvcs.w3.org/hg/webcomponents/rev/505225bb4a7b, the
custom elements spec no longer has the extra plumbing for
automatically creating all shadow trees along its inheritance chain.
This responsibility now falls to the developer of the custom element
to do this correctly (for example, by calling the callback of the

It's a trade-off between convenience and flexibility. When I spoke
with developers of the frameworks that are experimenting with shadow
DOM and custom elements, I found that there were already two different
ways (both slightly incompatible with what was currently spec'd) of
initializing the shadow trees. This told me that the spec had too much
opinion and it needed to get out of the way.


Received on Thursday, 21 February 2013 00:05:46 UTC