Add specific types for known HTML elements

[pelme]

instead of just

article = Element("article")

we could have something like:

class Article(Element): pass
article = Article("article")

then a component could use a more specific type annotation to ensure that the right html element is returned:

def my_component() -> h.Article:
    return h.article["hi!"]

with #111, we could also specify different kinds of attributes types for different elements.

[pelme]

cc @Majsvaffla

[gazpachoking]

I was thinking about this as well with regards to the completion. Seems like a good idea to me.

[pelme]

Nice! If anyone is interested in giving it a shot, feel free to send a PR!

[gazpachoking]

What do you think about generating the code for all of these? We could keep a list of all the elements, their base class, and what attributes they took and generate the code for them. This also means that attributes could be explicit keyword arguments rather than having to use typeddict, so mypy, IDEs would support everything without having to wait for features.

[pelme]

that sounds reasonable! I think the generated source file(s) should be checked into git. and then we need a CI job to make sure they are up to date. eventually when the PEP 728 is widely available we could potentially drop it this :)