Re: [webcomponents] Inheritance in Custom Elements (Was Proposal for Cross Origin Use Case and Declarative Syntax)

On Thu, Dec 5, 2013 at 7:55 PM, Ryosuke Niwa <rniwa@apple.com> wrote:

> On Nov 11, 2013, at 4:12 PM, Dimitri Glazkov <dglazkov@chromium.org>
> wrote:
> > 3) The approach pollutes global name space with constructors. This had
> been voiced many times as unacceptable by developers.
> >
> > 4) How does build a custom element that uses <name-card> as its base
> element? What about <div> or any other HTML element?
> >
> > The last one remains to be the hardest. The tortured inheritance support
> is what killed <element> in the first place. We can't ignore the
> inheritance, since it is clearly present, in both DOM and JS. If we attempt
> to punt on supporting it, our decisions cut off the opportunities to evolve
> this right in the future, and will likely leave us with boogers like
> multiple syntaxes for inheritance vs. non-inheritance use cases.
>
> What exactly are you referring to by inheritance support?


> Inheritance from all builtin elements (e.g. subclasses of HTMLElement)?
>
> Or inheritance from custom elements authors have defined?
>

Sure, both are fine. Why should we treat them differently?


>
> And could you give us a pointer for a list of concrete use cases?


Look at any mature Web framework. They all have hierarchies of objects:

http://docs.sencha.com/extjs/4.2.2/#!/api
http://quickui.org/catalog/

The latter is undergoing a complete rewrite to be custom element-based, so
you might find it useful to study:

https://github.com/JanMiksovsky/quetzal

If the atomic unit of your framework is a DOM element, then DOM elements
must support being extended via inheritance. Jan Miksovsky (cc'd) is a good
person to talk about inheritance properties of custom elements.

:DG<