[css-view-transitions-2] Specify view-transition-nane: match-element

[vmpstr]

[css-view-transitions-2] Specify view-transition-nane: match-element

Issue #10995

[noamr]

I am pretty sure I did this already in #11393

Was it omitted when merging L1 and L2?

[bramus]

Was it omitted when merging L1 and L2?

Sure looks like it. Because there are partial mentions of match-element in the current drafts (namely that match-element is not accepted as one of the custom-idents)

[bramus]

I dug in a bit more and I figured out: there is a section on auto naming with auto/match-element in the spec, but the problem is that the definition of the view-transition-name prop does not mention these keywords are possible values.

	<pre class=propdef>
	Name: view-transition-name
	Value: none | <<custom-ident>>
	Initial: none
	Inherited: no
	Percentages: n/a
	Computed Value: as specified
	Animation type: discrete
	</pre>

So my first suggestion would be to extend list of values for view-transition-name as follows:

- 	Value: none | <<custom-ident>>
+ 	Value: none | match-element | auto | <<custom-ident>>

Both terms could then use a (simple) description but one without an example, as the description can link to the section on auto naming for examples.

I’d also recommend to use “element identity” in the descriptions, as that’s the terminology we’ve used in the discussions and one that make it clear.

In https://developer.chrome.com/blog/view-transitions-in-2025#auto-name_elements_with_view-transition-name_match-element I also included the following note, which could make a good note in the spec as well:

Note: Elements in different documents have a different identity, therefore match-element can only be used in same-document view transitions.

[bramus]

(see previous comment)