Iteration of #60954.

This issue will be used to gather the new functionalities and bug fixes expected to be included in next WordPress releases. It will serve to share regular updates and progress.

Please keep in mind that the list of issues will change once new ones come up.

For this iteration, there will be two main focuses:

• Improve the UI and make it extensible: Right now, the UI to create bindings is only available post meta. The idea is to polish it and explore using DataViews, which comes with some benefits, and figure out the proper APIs to let other sources hook into this.
• Create mechanisms to support more blocks: As explained in this issue, there are a few limitations that need to be solved before allowing more blocks to use block bindings. Not all the limitations apply to all blocks, so the idea is to approach it progressively. For example, dynamic blocks only need the attributes locking and the opt-in mechanism solved. Or it can support basic CSS selectors as a first step for static blocks.

Block Bindings UI

• Allow to extend the block bindings UI- Block Bindings: API to extend the UI to external sources. #71542

Extensibility

Allow 3rd parties -- and Gutenberg -- to extend the list of blocks and block attributes that support block bindings.

• Use set_inner_html in bindings processing. Block Bindings: Add fallback for new features introduced in Core #71389
• Block Bindings: Allow filtering supported block attributes wordpress-develop#9392
• Block Bindings: Add block_bindings_supported_attributes filter wordpress-develop#9891
• Block Bindings: Communicate supported block attributes from server side wordpress-develop#9992
• Block Bindings: Communicate supported block attributes from server side #71820
• Block Transforms: In metadata transform, remove check for block bindings. #72389
• Pattern Overrides: Infer partial syncing supported blocks from the server #72391
• Remove core/entity binding in favour of post and term data bindings. Apply to Nav blocks. #72165
• Block Bindings: Migrate post-data and term-data source to use field instead of key args. #72382

Support for more blocks

• Add caption binding to Image Block. (Block Bindings: Add support to image caption attribute in block bindings #70642)
• Add bindings to Date Block. (Date block: Allow connecting to Block Bindings #70585)

Bug fixes

• Synced Pattern block: Pass block context to pattern content
• Block API: Add special case for metadata attribute in 'isUnmodifiedBlock' (Block API: Add special case for metadata attribute in 'isUnmodifiedBlock' #70903)
• Replace erroneous && with || (see https://github.com/WordPress/gutenberg/pull/71820/files#r2382958564).
  • Block Bindings: Refactor UI, improve consistency, add more info about source status. #72253
• Fix hover codevitals metric, see Block Bindings: Communicate supported block attributes from server side #71820 (comment)
  • Block Bindings: Move bindable attributes to privateContext. #72351
• Investigate if/why bindableAttributes (private context) is always undefined, see https://github.com/WordPress/gutenberg/pull/72401/files#r2438779624.
• Pattern Overrides: Add support for Image caption attribute #72476
• Block Bindings: In source definitions, turn editorUI into component #72367
• Post Date: Bindings UI show non date compatible strings. #72446
• A broken external source may break the UI. Add an ErrorBoundary. #72569

Needs discussion.

• Add more fields to the core/post-data source: title, status; potentially featured image (though that's complicated).
• Keep bindings editor calls in their own logic useSelect.
• Add bindings to Cover Block. Block Bindings: Add Cover block support. #72062

Postponed to 7.0

• Open more simple core blocks for bindings
• Change "This block is connected" indicator to make it accessible.
• Allow editing connected blocks in the site editor outside of post content.
  • Block Bindings: Edit connected blocks in site editor #66798
• Support for connecting custom fields in any template.
• Explore the possibility of abstracting async calls.
  • Block Bindings: Allow async call in getValues API #66962
• Open up "Pattern Overrides" and therefore intern block bindings to custom dynamic blocks: This one should be a consequence of working on the previous points.
  • Open up "Pattern Overrides" and therefore intern block bindings to custom dynamic blocks #64870
• Use HTML API CSS selectors in bindings processing.