[css-view-transitions-2] Allow an auto-generated `view-transition-name` that doesn't default to ID

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[css-view-transitions-2] Allow an auto-generated `view-transition-name` that doesn't default to ID #10995

Open noamr opened 2 weeks ago

noamr commented 2 weeks ago

In #8320, we resolved on using view-transition-name: auto as a way to generate names, using the element's id if exists. In the resolution, we said that we'll have another value for generating the name without falling back to ID, and perhaps yet another one for generating it only from ID.

Proposing:

Use view-transition-name: self as the keyword for generating the name ignoring ID. Other proposals that were raised were from-element and element-uuid().
No need for "generate from ID", once we have attr(<ident> id).

bramus commented 2 weeks ago

Copying over my comment from 8320 for visibility:

One thing I don’t like about from-element is that it reads like “read the id from the element” which authors will interpret as “read the id attribute from the element”. Ideally the value makes it clear that it’s an internal id, unrelated to the id attribute.

I think element-uuid as suggested in the OP comes closest to this.

noamr commented 2 weeks ago

Copying over my comment from 8320 for visibility:

One thing I don’t like about from-element is that it reads like “read the id from the element” which authors will interpret as “read the id attribute from the element”. Ideally the value makes it clear that it’s an internal id, unrelated to the id attribute. I think element-uuid as suggested in the OP comes closest to this.

Any thoughts on self?

bramus commented 1 week ago

Not a big fan of it, but also not against it.

I recently read up on first-valid() – which I didn’t know existed up until then.

This give me a new idea (which would alter the resolution from #8320): what if there was a function that allowed authors to list certain options and it returns the first non empty one?

auto = auto generate a name (element identity).
attr(id "<ident>") = use id attribute
first-non-empty(attr(id "<ident>"), auto) = try getting id attribute first. if there is none, fall back to auto behavior.

That would prevent a lot of confusion on the author side, as auto here now means “auto-generate a v-t-name”.

Otoh it would require a little more typing if they want the fallback behavior, but it would also allow authors to add more options to the fallback: e.g. first-non-empty(attr(id "<ident>"), attr(data-name "<ident>"), auto)

noamr commented 1 week ago

first-non-empty(attr(id "<ident>"), auto) = try getting id attribute first. if there is none, fall back to auto behavior.

That would prevent a lot of confusion on the author side, as auto here now means “auto-generate a v-t-name”.

Otoh it would require a little more typing if they want the fallback behavior, but it would also allow authors to add more options to the fallback: e.g. first-non-empty(attr(id "<ident>"), attr(data-name "<ident>"), auto)

To me this feels too verbose for a feature that's supposed to be a DX convenience... I think once attr is there we wouldn't need this. Though `first-non-empty might still be a valuable proposal regardless of auto view-transition-names.

I think the direction the auto resolution went with is is to have some keywords that have reasonable defaults and to leave attr etc. for the general-purpose more complex cases.