Mini Cart block is not available from the Edit template screen

[Aljullu]

When editing a template from the Edit template feature in the post/page editor, the Mini Cart block is not available.

To reproduce

1. From wp-admin, go to Pages and edit one of your pages.
2. In the Page sidebar, edit the template:

3. Notice the Mini Cart block is not available in the inserter (and if it was already in your header, an error is shown):

Expected behavior

It should be possible to insert the Mini Cart block from the template editor.

[Aljullu]

I wonder if we should revert the changes introduced in #5653. Thoughts @dinhtungdu @gigitux?

We might also take the chance to experimental with the new API introduced in WP 6.0 to filter allowed blocks based on the context: WordPress/gutenberg#28517 (comment).

[gigitux]

Nice shortcut for editing template!

I wonder if we should revert the changes introduced in #5653. Thoughts @dinhtungdu @gigitux?
We might also take the chance to experimental with the new API introduced in WP 6.0 to filter allowed blocks based on the context: WordPress/gutenberg#28517 (comment).

I agree with you! 👍

[dinhtungdu]

I wonder if we should revert the changes introduced in #5653.

Look like it's the way to go. $pagenow is not efficient when the Template Editor is loaded inside Block Editor.

[dinhtungdu]

We might also take the chance to experimental with the new API introduced in WP 6.0 to filter allowed blocks based on the context: WordPress/gutenberg#28517 (comment).

@Aljullu I tested using allowed_block_types_all, the filter is called when the post/page edit screen loads initially. But when editing the template from the Setting sidebar, the filter isn't called. I tested with both Core versions 5.9.3 and 6.0 beta.

[Aljullu]

Oh, too bad. Thanks for testing, @dinhtungdu! I wonder if we should comment in that issue or open a new one so GB devs are aware of this limitation?

[dinhtungdu]

I wonder if we should comment in that issue or open a new one so GB devs are aware of this limitation?

Sure thing! I will open an issue there for better visibility.

[dinhtungdu]

Sure thing! I will open an issue there for better visibility.

Opened WordPress/gutenberg#40780.