Indicate when a theme supports the Site editor in the Themes REST API response

[grantmkin]

I currently can't find a way to know if the active theme supports the Site editor based on the /themes REST API response for that theme.

We have theme supports data for block-template-parts in the response, which can be an indication of Site editor support, but use of this doesn't seem consistent. For example, Twenty Twenty-Two doesn't declare block-template-parts support, but it supports using the Site editor.

One way to know would be to surface the result of WP_Theme::is_block_theme for each theme (or at least for the active theme) in the API response.

Adds a is_block_theme property to each theme in the wp/v2/themes API response, which uses WP_Theme::is_block_theme.

This helps to indicate if a theme supports the Site editor, or not.

Trac ticket: https://core.trac.wordpress.org/ticket/58123

[ironprogrammer]

Welcome back to Trac, and thanks for the ticket and PR, @grantmkin!

This LGTM 👍🏻 Moving into the 6.3 milestone for consideration.

Test Report

Patch tested: ​https://github.com/WordPress/wordpress-develop/pull/4323

Steps to Test

1. Activate Gutenberg. This conveniently makes use of Core's wp/v2/themes endpoint.
2. Activate a block theme. This is needed to make the Editor available.
3. Navigate to Appearance > Editor (/wp-admin/site-editor.php).
4. In the browser console, inspect the network connections (in Chrome this is the Network tab), and filter results by "themes" and/or fetch/XHR requests. Reload the page if nothing is there the first try.
5. Locate the request for themes?context=edit... and preview/inspect the response.
6. 👀 Expand and inspect the data for each theme.
7. 🩹 Apply patch.
8. Refresh the page, and repeat Step 5.
9. 👀 Expand and inspect the data for each theme again.

Expected Results

After applying the patch:

• ✅ Observe that for block themes, the theme data includes is_block_theme: true.
• ✅ Observe that for classic themes, the theme data includes is_block_theme: false.

Environment

• Hardware: MacBook Pro Apple M1 Pro
• OS: macOS 13.4
• Browser: Google Chrome 114.0.5735.106
• Server: nginx/1.25.0
• PHP: 7.4.33
• WordPress: 6.3-alpha-55505-src
• Theme: twentytwentythree v1.1
• Active Plugins:
  • gutenberg v16.0.0

Actual Results

• ✅ Block themes (like TT3) include is_block_theme: true.
• ✅ Classic themes (like TT) include is_block_theme: false.

Supplemental Artifacts

Figure 1: Chrome DevTools Network tab themes endpoint response data for block theme.

Figure 2: Chrome DevTools Network tab themes endpoint response data for classic theme.

[zunaid321]

Test Report

This report validates that the indicated patch addresses the issue.

Patch tested: ​https://github.com/WordPress/wordpress-develop/pull/4323

Environment

• OS: Windows 11 (22H2)
• Web Server: nginx/1.23.4
• PHP: 7.4.33
• WordPress: 6.3-alpha-55505-src
• Browser: Chrome Version 114.0.5735.110 (Official Build) (64-bit)
• Theme: Twenty Twenty-Three

Before Applying The Patch

• Followed the instructions of @ironprogrammer
• ❌ is_block_theme - was not available

After Applying The Patch

• Followed the same instructions
• ✅ is_block_theme was displaying the correct info for both classic and block based themes.

Plugins Used

• Attached: gutenberg.16.0.0.zip

Screenshots

• Before Patch: ​https://prnt.sc/NWmL4MV5WVmf
• After Patch: ​https://prnt.sc/k-dcTe1S4jFq

[azaozz]

surface the result of WP_Theme::is_block_theme

Makes sense imho. The patch also looks good. Not sure if it needs two new tests for one boolean value, could they be combined? But the more-the merrier :)

[spacedmonkey]

Looks good to me. Marking as ready to commit.

[audrasjb]

Removing commit since I added a request to add the ticket number in the related unit tests functions.

[grantmkin]

Not sure if it needs two new tests for one boolean value, could they be combined?

Tests combined in ​https://github.com/WordPress/wordpress-develop/pull/4323/commits/a66c9f54db7ce63c2756b013bb37b1487078017b

Removing commit since I added a request to add the ticket number in the related unit tests functions.

Added in ​https://github.com/WordPress/wordpress-develop/pull/4323/commits/91750e63e3edd38a613a40f7ef07b9e8dfc76228

---

Let me know if there's anything else needed!

[audrasjb]

In 55951:

REST API: Indicate when a theme supports the Site editor in the Themes REST API response.

This changeset adds a is_block_theme property to each theme in the wp/v2/themes API response, which uses WP_Theme::is_block_theme to determinate whether
the theme is block theme or not.

Props grantmkin, ironprogrammer, zunaid321, azaozz, spacedmonkey, audrasjb, costdev.
Fixes #58123.

committed in https://core.trac.wordpress.org/changeset/55951