Section Styles: Register block style variations on init

[aaronrobertshaw]

Fixes: #62303

What?

Moves registration of theme json provided block style variations from the wp_theme_json_* filters to the init action.

Note: This brings the changes proposed in WordPress/wordpress-develop#6756 to Gutenberg.

Why?

Using the wp_theme_json_data_* filters is problematic: in some scenarios (e.g.: ) variations end up not being registered because those filters were not dispatched, hence their styles are not generated. Using init is in line with what themes have been doing until now in their functions.php and makes sure the style variations are registered in all the places.

How?

• Separates the registration of theme json provided block style variations from their resolution within their respective block types in the resulting theme.json data sets.
• Registration now occurs via the init action
• Updates test to ensure the registration is still triggered

Testing Instructions

1. Register style variations in all the places the theme is allowed to (use TT4).

In the theme.json file of the theme, paste the following under styles.blocks.variations:

"ThemeDark": {
    "blockTypes": [
        "core/group",
        "core/columns"
    ],
    "color": {
            "background": "blue"
    }
}

In the styles/ember.json (theme style variation) file, paste the following under styles.blocks.variations:

"VariationDark": {
    "blockTypes": [
        "core/group",
        "core/columns"
    ],
    "color": {
            "background": "yellow"
    }
}

Create a new file called styles/partial.json (partial theme.json), and paste the following:

{
        "$schema": "https://schemas.wp.org/trunk/theme.json",
        "version": 2,
        "title": "PartialDark",
        "blockTypes": [ "core/group", "core/columns", "core/media-text" ],
        "styles": {
                "color": {
                        "background": "green"
                }
        }
}

2. Open the site editor, go to Styles, apply the "Ember" theme style variation and save.
3. Go to the site editor, select a group block, and verify the three new style variations are available

4. Edit the styles of one of them, for example, PartialDark. Go to "Global Styles > Blocks > Group > PartialDark". Modify the background color to something else.
5. Save the post. The expected result is that it stays as it is (it's not reset to the default).

Screenshots or screencast

Before	After
Screen.Recording.2024-06-05.at.6.49.43.PM.mp4	Screen.Recording.2024-06-05.at.6.50.31.PM.mp4

[github-actions]

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Co-authored-by: aaronrobertshaw <aaronrobertshaw@git.wordpress.org>
Co-authored-by: oandregal <oandregal@git.wordpress.org>
Co-authored-by: annezazu <annezazu@git.wordpress.org>

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[github-actions]

This pull request has changed or added PHP files. Please confirm whether these changes need to be synced to WordPress Core, and therefore featured in the next release of WordPress.

If so, it is recommended to create a new Trac ticket and submit a pull request to the WordPress Core Github repository soon after this pull request is merged.

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Thank you! ❤️

View changed files

❔ lib/block-supports/block-style-variations.php
❔ phpunit/block-supports/block-style-variations-test.php

[aaronrobertshaw]

Is it better to call the registration function direct here or call do_action( 'init' );?

[aaronrobertshaw]

There's also an existing PR awaiting review to remove the core block style variation filters: #62090.

This PR then only adds the removal of core's init action for variation registration: a90b811

[ellatrix]

I just cherry-picked this PR to the wp/6.6-beta-3 branch to get it included in the next release: d633a42