Re: ES6 and upgrading custom elements

On Tue, Jan 6, 2015 at 10:59 AM, Anne van Kesteren <annevk@annevk.nl> wrote:

> On Tue, Jan 6, 2015 at 7:54 PM, Dimitri Glazkov <dglazkov@google.com>
> wrote:
> > Right, that's why to create a valid custom element that subclasses
> > HTMLInputElement, you should use type extensions. With type extensions,
> the
> > HTMLInputElement is what's instantiated.
>
> But without using type extensions this will work (provided we sort out
> the other bits):
>
>   class X extends HTMLInputElement { ... }
>   document.registerElement("x-input", X)
>   var xinput = new X
>
> It seems sad to require type extensions (and therefore requiring a
> more complicated version of document.registerElement) for translating
> this into markup.
>

You shouldn't need anything more complicated:

class X extends HTMLInputElements { .. }
X.extends = "input" // additional line.
document.register("x-input", X)
var xinput = new X


>
> Having actual subclassing in JavaScript, but not for elements unless
> you use some sort of hack seems sad.
>

The type extensions is a hack, I agree :(

:DG<