Re: [Shadow] Q: Removable shadows (and an idea for lightweight shadows)?

On Thu, Mar 26, 2015 at 11:36 AM, Travis Leithead <
travis.leithead@microsoft.com> wrote:

> > From: Justin Fagnani [mailto:justinfagnani@google.com]
> >> Elements expose this “shadow node list” via APIs that are very similar
> to
> >> existing node list management, e.g., appendShadowChild(),
> insertShadowBefore(),
> >> removeShadowChild(), replaceShadowChild(), shadowChildren[],
> shadowChildNodes[].
> >
> >This part seems like a big step back to me. Shadow roots being actual
> nodes means
> >that existing code and knowledge work against them.
>
> "existing code and knowledge work against them" -- I'm not sure you
> understood correctly.
>

No, I think I understood :)

ShadorRoot extends DocumentFragment, and thus Node and has all the API yo
would expect like querySelector(), qsA(), childNodes(), textContent,
appendChild(), cloneNode(), insertBefore(), etc... You can pass a
ShadowRoot to any API expecting a node. For instance, deep traversal though
shadow trees only requires updating normal traversal to crawl into shadows,
it doesn't require teaching it a multitude of shadow*() methods.


> Nodes in the "shadow child list" wouldn't show up in the childNodes list,
> nor in any of the
> node traversal APIs (e.g., not visible to qSA, nextSibling,
> previousSibling, children, childNodes,
> ect.
>
> Trivially speaking, if you wanted to hide two divs that implement a "stack
> panel" and have some
> element render it, you'd just do:
> element.appendShadowChild(document.createElement('div'))
> element.appendShadowChild(document.createElement('div'))
>
> Those divs would not be discoverable by any traditional DOM APIs (they
> would now be on the
> "shadow side"), and the only way to see/use them would be to use the new
> element.shadowChildren
> collection.
>

As in the current API where the only way to see shadow children is by
accessing a shadow root. Your examples become:
element.shadowRoot.appendChild(document.createElement('div'))
element.shadowRoot.appendChild(document.createElement('div'))

Or things like: function writeDivSoup(container){...}, which will work as
writeDivSoup(element.shadowRoot)


> But perhaps I'm misunderstanding your point.
>
> >The API surface that you'd have to duplicate with shadow*() methods would
> be quite large.
>
> That's true. Actually, I think the list above is probably about it.
>

querySelector(), find() and friends are important. Plus, speaking of find()
what about additions to Node and DocumentFragment in the future? Do you
keep just adding things like queryShadowSelector() and shadowFind()?