Constructors for some DOM types may simply throw.

[joshualitt]

Currently, there are many constructors that throw. For example, web.HTMLDivElement(). We should either lower these like dart:html to document.createElement, or we should find some way to disallow invoking the constructor statically, i.e. a lint.

[eernstg]

Would abstract class work?

[joshualitt]

Hmm, maybe it would? Would you prefer a magic constructor that calls document.createElement or should we make it a static error to use the constructor?

[eernstg]

I was just suggesting abstract because that seemed to be a good fit for one of the approaches that you mentioned: 'disallow invoking the constructor statically'. That would prevent instance creations and still allow superinitializations in other constructors (but it looks like there are no subclass relationships, only implements, so we can't have super(...) anyway). On the other hand, if document.createElement("Something") can actually be called with an argument that yields a useful outcome then that sounds more pragmatic.

In any case, I just noticed the language perspective on this question—it would a serious mistake to assume that I can say anything useful about web programming. ;-)

[sigmundch]

What if we don't emit them?

We may get issues today in our current staticInterop implementation, so we may need to emit a private unaccessible constructor instead? (dart:html does both that and the factory that uses createElement) to make sure the classes remain sealed.

Howevr, once we switch to inline-classes, does this problem go away and we can simply omit a constructor altogether?

[eernstg]

we can simply omit a constructor altogether?

I would think so.

[sigmundch]

I ran again into these, so I'd suggest we do make a change to make these stand out more easily:

• add a _ constructor that throws. This changes the default behavior and removes the default constructor from our classes:

@staticInterop @JS
class HTMLDivElement ... {
  HTMLDivElement._() => throw "unsupported";
}

• once we have the new language syntax, we can leave them out entirely.
• once the language introduces static extension members, we can introduce factories that call document.createElement from the glue layer.

[srujzs]

Handled in #185.