wp-embed-aspect class not working well in Youtube block

[rodica-andronache]

Description

In the Youtube block, you can change the aspect ration of the video using the wp-embed-aspect class, but in Neve this does not work.
https://wordpress.org/support/topic/neve-theme-takes-over-youtube-native-embed-and-breaks-flexibilty-of-ratio-for-sh/

Step-by-step reproduction instructions

1. Create a post with the Youtube block
2. Add a video and go to Advanced > ADDITIONAL CSS CLASS(ES) and try to change the wp-embed-aspect class.
3. The aspect ration does not apply in frontend ( This works well in 2023 theme, for example )

Screenshots, screen recording, code snippet or Help Scout ticket

https://vertis.d.pr/v/x1xCSt

Environment info

No response

Is the issue you are reporting a regression

No

[cristian-ungureanu]

Hey @rodica-andronache, after doing a bit of research here's what I found:

The Gutenberg embed block supports adding responsive wrappers around embeds that are cognizant of the embed's aspect ratio. Without creating fixed-width columns, the embed will fill its container at the interpreted aspect ratio.
If you're still writing PHP templates, you're using wp_oembed_get, which does not support this. This ticket suggests that some JS fires to adjust the height on iframes on window resize, but that's a somewhat different issue, becoming important after the embed has been rendered. That ticket also suggests that an embed expanding to fill its container is undesirable and not in-line with oEmbed's specification, but whoever designed the Gutenberg block must have had a different interpretation of that spec.

source: https://core.trac.wordpress.org/ticket/54468

In other words, this feature will only work for FSE themes.

[rodica-andronache]

@cristian-ungureanu ok, got it, indeed it seems to works just in FSE themes