[css-device-adapt] Should Device Adaptation include a normative definition of <meta> viewport?

[ChumpChief]

Spec: https://drafts.csswg.org/css-device-adapt/

The viewport tag is absolutely essential for correct rendering of any mobile content, yet is not normatively defined. Should it be? I think the answer is yes.

[frivoal]

Yes, the web totally depends on it, there is a lot of interoperability, it should be specified, and the css-device-adapt spec looks like a good place to do it. Even though the syntax of the viewport tag isn't CSS, what it affects is absolutely in scope, so that's good. That also lets us say what happens if you use both.

The current informative definition probably needs some extra scrutiny before we can simply turn it into being normative, but it's a decent start.

There's one thing I am not sure about: in #258 (and the follow up conversation that's should happen in #326 & #327), there have been questions that @Viewport shouldn't have nearly as many features than it currently does, and that maybe it needs to be parred down to only with:auto or min-width: <lenght>. The current definition of @Viewport is featurefull enough that we can express the viewport tag in terms of @Viewport. If we do the simplification, that will no longer be true though.

[fantasai]

Two points:

1. I think it should be the goal of @Viewport to fully replace the viewport
2. I totally agree we should define viewport in Device Adaptation. If you want a WG resolution to that effect, add
   Agenda+? :)

~fantasai

[foolip]

After the blink-dev Intent to Implement: @viewport it looks unlikely that @viewport will become implemented everywhere. @bokand @yoavweiss, would you agree?

What would be the best place to move the definition of https://drafts.csswg.org/css-device-adapt/#viewport-meta and making it normative? There are bugs about this in Gecko, and we need something to write tests against. @miketaylr FYI.

[bokand]

I would agree we're unlikely to ever ship it, given the perf concerns raised by Yoav.

I don't know where the remaining parts of the spec should go except that it should probably end up in the same spec as visualViewport spec and the layout/visual viewport once we spec those.

[foolip]

Would that be https://github.com/WICG/ViewportAPI, or should it be a spec on which that builds?

[bokand]

I think someone mentioned at one point it would probably make sense in CSSOM-View, but I don't really know how spec-land is devided so I don' treally have an opinion.

[foolip]

CSSOM View sounds reasonable, yeah. @zcorpan, WDYT?

[frivoal]

There are some high level concepts in @viewport that are think are worth it:

• This is about styling, interelated with layout, and should be in CSS
• It can express "this layout breaks down if the viewport is smaller than / larger than FOO"

Other than that, I like the current design, but wouldn't mind a complete overhaul of the design, if that helped address the concerns.

Either way, I think the CSSWG should indeed take step back, and think about the future of this module, because currently it does not seem to be on a good path.

[foolip]

So what's the best destination for meta viewport?

[frivoal]

@foolip hard to say before we decide the fate of that module. If it should survive, in this form or another one, this is the right place. if not, the I guess CSSOM View isn't too bad. Of we could gut this module of everything other than the meta viewport (which would make me sad, but you don't always get what you want).