#908: View Transitions: list of types

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Opened Oct 12, 2023

こんにちは TAG-さん!

I'm requesting a TAG review of View Transitions: list of types.

The View Transitions feature allows developers to create transitions between DOM states. A significant portion of the transition is a declarative set up, followed by a script trigger. This works well for a single type of transition. However, developers have expressed interest to be able to declare multiple transitions in their CSS, and then trigger only one of them from script. The list of types proposal attempts to address this use case.

Further details:

  • I have reviewed the TAG's Web Platform Design Principles
  • Relevant time constraints or deadlines: None
  • The group where the work on this specification is currently being done: CSSWG
  • The group where standardization of this work is intended to be done (if current group is a community group or other incubation venue): CSSWG
  • Major unresolved issues with or opposition to this specification: We have not head of opposition, but some bikeshedding on the names remains to be done.
  • This work is being funded by: Google

💬 leave review feedback as a comment in this issue and @-notify @vmpstr @noamr

Discussions

Discussed Nov 1, 2023 (See Github)

Lea: seemes to be adding syntax to do something that is already possible. Adding syntax to work around a performance issue in implementations, rather than focusing efforts on fixing the perf issue. Then again, being realistic might mean we need this sort of thing.

Peter: is it just a perf issue?

Lea: if you look at the linked issue, the only reason this is needed is that using has very high up the tree is slow. Explainer is minimal. Use case is a link to an issue.

Dan: no alternatives considered. Developer complexity?

Lea: [leaves feedback]

Discussed Nov 1, 2023 (See Github)

we review their response

Peter: I don't see a use case described in the explainer... I see a developer need...

Dan: should we press them on this point?

Peter: I still don't get it...

Dan: they're conflating user needs with developer needs

Peter: I can leave the feedback...

Lea: I think view transitions are overly complex...

Peter: I don't understand the use case - my feedback is that they are pointing to a use case and it's not a use case...

Lea: how is this done today and how will this be done with what they are proposing? I can see how this could be useful...

Comment by @LeaVerou Nov 13, 2023 (See Github)

Hi @vmpstr,

We just took this up on our breakout A today, but we couldn't find a list of use cases in the explainer. There was this issue which is linked, but it was not clear to us whether that is the only use case, or whether there are more. It would also be useful to include any alternatives considered. Please take a look here for more advice on writing effective explainers.

Comment by @vmpstr Nov 13, 2023 (See Github)

Hi @LeaVerou,

Thank you for the feedback. The use-case described in https://github.com/w3c/csswg-drafts/issues/8960 is the same use-case described in the explainer, and is the main use-case for this API addition to the View Transitions feature.

We are also discussing using types for a similar use-case in the cross-document navigation case, where the polyfill is potentially harder to implement. We are early in the discussion of how types can be used in that case though.

I've added alternatives considered section that mentions this as well.

Discussed Dec 1, 2023 (See Github)

Explainer has been updated, ready for review

Matthew: view transitions parent spec doesn't have accessibility considerations. Homework for APA to propose one for CSS. Don't anticipate any concerns.

Discussed May 1, 2024 (See Github)

Deferring to assignees.

Discussed Aug 1, 2024 (See Github)

Dan: I suggest we close this as the requestor did respond to Lea's feedback and it's been in the abyss since...

Yves: mozilla standards position was positive for list of types...

Dan: so tick mark for multi-implementer support...

Dan: Where is happening?

Yves: CSS....

Dan: So shall we close it as satisfied?

Peter: seems we're looking at details but I don't have a good understanding of big picture.

Dan: looking back at original review: https://github.com/w3ctag/design-reviews/issues/748 we said satisfied with concerns. We did articulate our concerns...

Peter: i agree we gave view transitions a pass but the things they are adding to it seem suspect to me...

Dan: Does it have CSS wg consensus?

Peter: not sure. ...concerns about list of types... changes to the javascript APIs... so let's go ahead and close it.

CLOSED AS SATISFIED

Comment by @torgo Aug 12, 2024 (See Github)

Hi - we are just tidying this up as we should have closed this earlier. We're happy with this so we are closing it as satisfied.