Theme switching flows tracking issue

[priethor]

With the introduction of Block Themes in WordPress 5.9, there are a few considerations to take into account when switching block themes or when upgrading from a classic one:

Theme selection

• Browse Mode: Add theme previews #47228

Template and themes decoupling

• Remove coupling of templates, parts, and patterns when switching themes #25071
• Templates: Retain custom templates when switching themes #31954

Navigation

• Preserve the navigation on theme switch #38291
• Automatically utilise classic menu when switching from classic Theme #42600

Styles

• Clear block-level inline styles on theme switch and other actions that affect global styling #21045
• Proposal: Standardized block markup, theme.json design tokens, and CSS classes to improve interoperability #38998
• Standardizing required theme CSS Variables #33180

Classic theme upgrading and backwards compatibility

• Provide a pathway to migrate widgets to block themes #39270
• An equivalent to "Inactive Widgets" for template parts #31397
• FSE themes should have a way to set a default header and footer that maps to traditional header.php and footer.php in terms of backwards compatible loading #33989

[adamziel]

@priethor these issues do not seem to have been very active recently. Is there any feature that you think could land until Wednesday next week to be included in WordPress 6.0 release? To increase visibility, we can add it to the WordPress Editor 6.0 project board.

[priethor]

I don't think anything here is to be expected in WordPress 6.0, but we should start working on theme switching early after beta towards 6.1.

[spacedmonkey]

If I am understanding correctly, the theme switching process is changing. This will likely mean a rewrite in react and will require more REST API interactions. Currently the themes REST API is extremely limited, only be able to list single and all themes. The functionality to activate / deactivate / install / delete themes is not part of the REST API. There is an existing ticket #54293. If require for this functionality, let's highlight this early and add to the 6.1 milestone.

I am going to CC @TimothyBJacobs for his input

[TimothyBJacobs]

I don't have much to add beyond what you mentioned @spacedmonkey. The REST API endpoints will need to be expanded following the patterns we introduced in the Plugins controller.

If this is going to be a priority for WordPress 6.1, it'd be great to get confirmation of that early in the cycle.

[spacedmonkey]

Made a start of the themes REST API - #41836

[annezazu]

In light of feedback from the FSE Outreach Program's seventeenth call for testing, I've added #42600 under Navigation above as this feels like an important, high impact item to handle as it relates to navigation and switching from classic to block.

[scruffian]

Should we add this?: #47228