[Shadow DOM] Simplifying level 1 of Shadow DOM

(Resent from correct email address)

Hi,

First off, thanks to Dimitri and others for all the great work on Shadow
DOM and the other pieces of Web Components. While I'm very enthusiastic
about Shadow DOM in the abstract, I think things have gotten really
complex, and I'd like to seriously propose that we simplify the feature
for 1.0, and defer some complexity to the next level.

I think we can address most of the use cases of shadow DOM while
seriously reducing the complexity of the feature by making one change:
What if we only allowed one insertion point in the shadow DOM? Having
just 1 insertion point would let us push (most? all?) of this complexity
off to level 2:

* distribution, getDistributedNodes(), etc.
* selector fragments & matching criteria
* /select/ combinator
* <content select>
* <shadow> ?
* reprojection

Notably, I don't think insertion point(s) get used (much or at all) in
WebKit's internal shadow trees, so I don't think all of the above
complexity is worth it right now. Baby Steps.[1]



Ted

1. The lost HTML design principle:
  http://www.w3.org/html/wg/wiki/DesignPrinciplesReview#Baby_Steps