WebIDL: Support the HTMLConstructor attribute

[alexcrichton]

Right now we're not processing it which means a lot of types don't have constructors!

There may be some assorted constructor attributes that also need special handling as well, will require some investigation.

[ohanar]

So the WebIDL spec doesn't specify the HTMLConstructor anywhere. Is there anything special about these constructors?

[alexcrichton]

Perhaps not! It sounds like we may be able to treat it as a normal constructor perhaps? (I'm not too knowledgeable of what it is either!)

[fitzgen]

I am confused

[fitzgen]

https://html.spec.whatwg.org/multipage/dom.html#htmlconstructor

[alexcrichton]

Interesting! Does that mean that there's nothing actually to do here?

[fitzgen]

I think so. I find that series of steps somewhat impenetrable. I tried a bunch of things, and I couldn't get anything that wouldn't throw an error.

[alexcrichton]

Ok cool!

[Pauan]

I believe they just exist so that custom elements can work:

class Foo extends HTMLDivElement {
    ...
}

My understanding of the spec is that new HTMLDivElement() and HTMLDivElement() should both throw errors.

So indeed they cannot be created directly (only indirectly by creating a new class that extends from them).