From c3f257c4d400dd8752b46d6da5da099605572749 Mon Sep 17 00:00:00 2001 From: JuanMa Date: Thu, 4 Dec 2025 15:30:59 +0000 Subject: [PATCH 1/7] Enhance Block Bindings Documentation: Add details on customizing supported attributes and introduce `getFieldsList` function for dynamic sources (since WordPress 6.9). --- .../block-api/block-bindings.md | 77 +++++++++++++++++++ 1 file changed, 77 insertions(+) diff --git a/docs/reference-guides/block-api/block-bindings.md b/docs/reference-guides/block-api/block-bindings.md index dc4e397f1a9d42..c92d18677e9d5f 100644 --- a/docs/reference-guides/block-api/block-bindings.md +++ b/docs/reference-guides/block-api/block-bindings.md @@ -133,6 +133,26 @@ function wpmovies_format_visualization_date( $value, $name ) { add_filter( 'block_bindings_source_value', 'wpmovies_format_visualization_date', 10, 2 ); ``` +#### Customizing supported attributes filter + +_**Note:** Since WordPress 6.9._ + +The `block_bindings_supported_attributes_{$block_type}` filter allows developers to customize which of a block's attributes can be connected to a Block Bindings source. + +This filter provides a way to extend or restrict which attributes of a specific block type can be bound to dynamic sources. + +Example: + +```php +// Allow binding the 'className' attribute for paragraph blocks +add_filter( 'block_bindings_supported_attributes_core/paragraph', function( $attributes ) { + $attributes['className'] = array( + 'type' => 'string', + ); + return $attributes; +} ); +``` + #### Server registration Core examples There are a few examples in Core that can be used as reference. @@ -157,6 +177,7 @@ The function to register a custom source is `registerBlockBindingsSource( args ) - `getValues`: `function` that retrieves the values from the source. (optional) - `setValues`: `function` that allows updating the values connected to the source. (optional) - `canUserEditValue`: `function` to determine if the user can edit the value. The user won't be able to edit by default. (optional) + - `getFieldsList`: `function` that returns available fields for the UI dropdown selector. (_Since WordPress 6.9_) (optional) This example will show a custom post meta date in the editor and, if it doesn't exist, it will show today's date. The user can edit the value of the date. (Caution: This example does not format the user input as a date—it's only for educational purposes.) @@ -232,6 +253,60 @@ The `setValues` function updates all the values of the source of the block bound - `dispatch` returns an `object` of the store's action creators. [More about dispatch](https://developer.wordpress.org/block-editor/reference-guides/packages/packages-data/#dispatch). - `select` returns an `object` of a given store's selectors. [More info in their docs.](https://developer.wordpress.org/block-editor/reference-guides/packages/packages-data/#select). +#### getFieldsList + +_**Note:** Since WordPress 6.9._ + +The `getFieldsList` function enables custom sources to appear in the Block Bindings UI dropdown selector. When a user selects an option from the dropdown, the source is automatically bound to the block attribute with the corresponding `args` from the selected field. This function must return an array of field objects that define the available binding options. + +Each field object in the array should have the following properties: + +- `label`: `string` that defines the label shown in the dropdown selector. Defaults to the source label if not provided. +- `type`: `string` that defines the attribute value type. It must match the attribute type it binds to; otherwise, it won't appear in the UI. For example, an `id` attribute that accepts only numbers should only display fields that return numeric values. +- `args`: `object` that defines the source arguments that are applied when a user selects the field from the dropdown. + +Example: + +```js +registerBlockBindingsSource( { + name: 'my-plugin/custom-fields', + label: 'Custom Fields', + getFieldsList() { + return [ + { + label: 'Author Name', + type: 'string', + args: { + field: 'author_name', + }, + }, + { + label: 'Publication Year', + type: 'string', + args: { + field: 'publication_year', + }, + }, + { + label: 'Page Count', + type: 'number', + args: { + field: 'page_count', + }, + }, + ]; + }, + getValues( { bindings } ) { + // Implementation to retrieve values based on args.field + }, +} ); +``` + +With this implementation, users will see "Author Name", "Publication Year", and "Page Count" as options in the Block Bindings UI dropdown when binding block attributes to your custom source. + +
+Check the Editor Bindings example from the Block Development Examples repo +
#### Editor registration Core examples @@ -240,6 +315,8 @@ There are a few examples in Core that can be used as reference. - Post Meta. [Source code](https://github.com/WordPress/gutenberg/blob/5afd6c27bfba2be2e06b502257753fbfff1ae9f0/packages/editor/src/bindings/post-meta.js#L74-L146) - Pattern overrides. [Source code](https://github.com/WordPress/gutenberg/blob/5afd6c27bfba2be2e06b502257753fbfff1ae9f0/packages/editor/src/bindings/pattern-overrides.js#L8-L100) + + ## Unregistering a source _**Note:** Since WordPress 6.7._ From 0b767749a3ff14476f7625286c056db1184e5df0 Mon Sep 17 00:00:00 2001 From: JuanMa Date: Fri, 19 Dec 2025 10:15:00 +0100 Subject: [PATCH 2/7] Update Block Bindings Documentation: Expand compatibility section with core blocks and attributes, introduce core sources for block bindings, and provide detailed examples for `core/post-meta`, `core/post-data`, `core/term-data`, and `core/pattern-overrides`. --- .../block-api/block-bindings.md | 344 +++++++++++++----- 1 file changed, 257 insertions(+), 87 deletions(-) diff --git a/docs/reference-guides/block-api/block-bindings.md b/docs/reference-guides/block-api/block-bindings.md index c92d18677e9d5f..333fc41c078163 100644 --- a/docs/reference-guides/block-api/block-bindings.md +++ b/docs/reference-guides/block-api/block-bindings.md @@ -20,17 +20,194 @@ An example could be connecting an Image block `url` attribute to a function that } --> ``` - ## Compatible blocks and their attributes Right now, not all block attributes are compatible with block bindings. There is some ongoing effort to increase this compatibility, but for now, this is the list: -| Supported Blocks | Supported Attributes | -| ---------------- | -------------------- | -| Paragraph | content | -| Heading | content | -| Image | id, url, title, alt | -| Button | text, url, linkTarget, rel | +| Supported Blocks | Supported Attributes | +| ------------------------ | --------------------------------- | +| core/image | id, url, title, alt, caption | +| core/heading | content | +| core/paragraph | content | +| core/button | url, text, linkTarget, rel | +| core/navigation-link | url | +| core/navigation-submenu | url | + +## Core Sources + +WordPress includes several built-in block bindings sources that you can use without any custom registration. + +- [core/post-meta](#corepost-meta) +- [core/post-data](#corepost-data) +- [core/term-data](#coreterm-data) +- [core/pattern-overrides](#corepattern-overrides) + +### core/post-meta + +The `core/post-meta` source allows you to bind block attributes to post meta fields. + +**Requirements:** + +- Post meta must be registered with `show_in_rest => true` +- Post meta keys cannot start with an underscore (protected keys are not accessible) + +**Example usage:** + +First, register your post meta: + +```php +register_meta( + 'post', + 'my_custom_field', + array( + 'show_in_rest' => true, + 'single' => true, + 'type' => 'string', + ) +); +``` + +Then bind it to a block attribute: + +```html + +

Fallback content

+ +``` + +### core/post-data + +_**Note:** Since WordPress 6.9._ + +The `core/post-data` source provides access to post data fields. + +**Available fields:** + +- `date` - The post publication date +- `modified` - The post last modified date +- `link` - The post permalink + +**Example usage:** + +```html + +

Fallback content

+ +``` + +### core/term-data + +_**Note:** Since WordPress 6.9._ + +The `core/term-data` source provides access to taxonomy term data fields when term context is available. It requires `termId` and `taxonomy` context to function properly [1](#9-0) . + +#### Available Fields + +| Field | Description | Example Output | +|-------|-------------|----------------| +| `id` | Term ID | `123` | +| `name` | Term name | `Category Name` | +| `link` | URL to term archive | `https://example.com/category/news` | +| `slug` | URL-friendly slug | `category-slug` | +| `description` | Term description | `A description of the category` | +| `parent` | Parent term ID (hierarchical taxonomies) | `0` | +| `count` | Number of posts in this term | `5` | [2](#9-1) + +#### Example Usage + +**Display term names in a list:** + +```html + + + +

Category Name

+ + + +``` + +**Create linked term archives:** + +```html + + + + Tag Name + + + +``` + +#### Context Requirements + +The `core/term-data` source works in these contexts: + +1. **Term Templates** - Automatically provides context for each term +2. **Navigation Blocks** - Special backwards compatibility handling for `core/navigation-link` and `core/navigation-submenu` +3. **Custom Context** - Any template that provides `termId` and `taxonomy` context + +### core/pattern-overrides + +The `core/pattern-overrides` source enables pattern instances to have their content overridden on a per-instance basis. This is particularly useful for synced patterns where you want to allow specific blocks to be customized while keeping the rest of the pattern synchronized . + +**How it works:** + +- Pattern blocks can define which attributes are overridable using `metadata.bindings` +- Each pattern instance stores its override values in the `content` attribute +- The binding connects the block attribute to the override value using the block's `metadata.name` as a key +- The context structure follows: `pattern/overrides → {block_name} → {attribute_name}` + +**Example usage:** + +In the pattern definition, mark blocks as overridable: + +```html + +

Default heading text

+ +``` + +When the pattern is instantiated, users can override the content for that specific instance: + +```html + +``` + +In this example: + +- **`custom-heading`** is a unique identifier for the `core/paragraph` block within the `core/pattern-overrides` system. +- It acts as a key in the overrides context structure: `pattern/overrides → custom-heading → content`. +- This identifier allows multiple blocks of the same type (e.g., `core/paragraph`) within a pattern to have distinct, per-instance attribute overrides using `metadata.name`. + +For instance, `"custom-heading"` links the specific paragraph block's `content` attribute to its override value (`"My custom heading text"`) for a particular pattern instance. ## Registering a custom source @@ -48,11 +225,11 @@ Server registration allows applying a callback that will be executed on the fron The function to register a custom source is `register_block_bindings_source($name, $args)`: -- `name`: `string` that sets the unique ID for the custom source. -- `args`: `array` that contains: - - `label`: `string` with the human-readable name of the custom source. - - `uses_context`: `array` with the block context that is passed to the callback (optional). - - `get_value_callback`: `function` that will run on the bound block's render function. It accepts three arguments: `source_args`, `block_instance` and `attribute_name`. This value can be overridden with the filter `block_bindings_source_value`. +- `name`: `string` that sets the unique ID for the custom source. +- `args`: `array` that contains: + - `label`: `string` with the human-readable name of the custom source. + - `uses_context`: `array` with the block context that is passed to the callback (optional). + - `get_value_callback`: `function` that will run on the bound block's render function. It accepts three arguments: `source_args`, `block_instance` and `attribute_name`. This value can be overridden with the filter `block_bindings_source_value`. Note that `register_block_bindings_source()` should be called from a handler attached to the `init` hook. @@ -110,11 +287,11 @@ _**Note:** Since WordPress 6.7._ The value returned by `get_value_callback` can be modified with the `block_bindings_source_value` filter. The filter has the following parameters: -- `value`: The value to be filtered. -- `name`: The name of the source. -- `source_args`: `array` containing source arguments. -- `block_instance`: The block instance object. -- `attribute_name`: The name of the attribute. +- `value`: The value to be filtered. +- `name`: The name of the source. +- `source_args`: `array` containing source arguments. +- `block_instance`: The block instance object. +- `attribute_name`: The name of the attribute. Example: @@ -137,9 +314,11 @@ add_filter( 'block_bindings_source_value', 'wpmovies_format_visualization_date', _**Note:** Since WordPress 6.9._ -The `block_bindings_supported_attributes_{$block_type}` filter allows developers to customize which of a block's attributes can be connected to a Block Bindings source. +The `block_bindings_supported_attributes_{$block_type}` filter allows developers to customize which of a block's attributes can be connected to a Block Bindings source. This filter enables the Block Bindings UI in the editor for the specified attributes. -This filter provides a way to extend or restrict which attributes of a specific block type can be bound to dynamic sources. +This filter provides a way to extend or restrict which attributes of a specific block type can be bound to dynamic sources. The attributes registered through this filter will appear as options in the block binding interface. + +**Note:** This filter is currently not implemented for pattern overrides. Example: @@ -157,10 +336,9 @@ add_filter( 'block_bindings_supported_attributes_core/paragraph', function( $att There are a few examples in Core that can be used as reference. -- Post Meta. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/block-bindings/post-meta.php) -- Pattern overrides. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/block-bindings/pattern-overrides.php) -- Twenty Twenty-Five theme. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-content/themes/twentytwentyfive/functions.php) - +- Post Meta. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/block-bindings/post-meta.php) +- Pattern overrides. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/block-bindings/pattern-overrides.php) +- Twenty Twenty-Five theme. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-content/themes/twentytwentyfive/functions.php) ### Editor registration @@ -170,22 +348,19 @@ Editor registration on the client allows defining what the bound block will do w The function to register a custom source is `registerBlockBindingsSource( args )`: -- `args`: `object` with the following structure: - - `name`: `string` with the unique and machine-readable name. - - `label`: `string` with the human readable name of the custom source. In case it was defined already on the server, the server label will be overridden by this one, in that case, it is not recommended to be defined here. (optional) - - `usesContext`: `array` with the block context that the custom source may need. In case it was defined already on the server, it should not be defined here. (optional) - - `getValues`: `function` that retrieves the values from the source. (optional) - - `setValues`: `function` that allows updating the values connected to the source. (optional) - - `canUserEditValue`: `function` to determine if the user can edit the value. The user won't be able to edit by default. (optional) - - `getFieldsList`: `function` that returns available fields for the UI dropdown selector. (_Since WordPress 6.9_) (optional) - +- `args`: `object` with the following structure: + - `name`: `string` with the unique and machine-readable name. + - `label`: `string` with the human readable name of the custom source. In case it was defined already on the server, the server label will be overridden by this one, in that case, it is not recommended to be defined here. (optional) + - `usesContext`: `array` with the block context that the custom source may need. In case it was defined already on the server, it should not be defined here. (optional) + - `getValues`: `function` that retrieves the values from the source. (optional) + - `setValues`: `function` that allows updating the values connected to the source. (optional) + - `canUserEditValue`: `function` to determine if the user can edit the value. The user won't be able to edit by default. (optional) + - `getFieldsList`: `function` that returns available fields for the UI dropdown selector. (_Since WordPress 6.9_) (optional) This example will show a custom post meta date in the editor and, if it doesn't exist, it will show today's date. The user can edit the value of the date. (Caution: This example does not format the user input as a date—it's only for educational purposes.) ```js -import { - registerBlockBindingsSource, -} from '@wordpress/blocks'; +import { registerBlockBindingsSource } from '@wordpress/blocks'; import { __ } from '@wordpress/i18n'; import { store as coreDataStore } from '@wordpress/core-data'; @@ -235,10 +410,10 @@ registerBlockBindingsSource( { The `getValues` function retrieves the value from the source on block loading. It receives an `object` as an argument with the following properties: -- `bindings` returns the bindings object of the specific source. It must have the attributes as a key, and the value can be a `string` or an `object` with arguments. -- `clientId` returns a `string` with the current block client ID. -- `context` returns an `object` of the current block context, defined in the `usesContext` property. [More about block context.](https://developer.wordpress.org/block-editor/reference-guides/block-api/block-context/). -- `select` returns an `object` of a given store's selectors. [More info in their docs.](https://developer.wordpress.org/block-editor/reference-guides/packages/packages-data/#select). +- `bindings` returns the bindings object of the specific source. It must have the attributes as a key, and the value can be a `string` or an `object` with arguments. +- `clientId` returns a `string` with the current block client ID. +- `context` returns an `object` of the current block context, defined in the `usesContext` property. [More about block context.](https://developer.wordpress.org/block-editor/reference-guides/block-api/block-context/). +- `select` returns an `object` of a given store's selectors. [More info in their docs.](https://developer.wordpress.org/block-editor/reference-guides/packages/packages-data/#select). The function must return an `object` with this structure: `{ 'block attribute' : value }` @@ -247,11 +422,11 @@ The function must return an `object` with this structure: The `setValues` function updates all the values of the source of the block bound. It receives an `object` as an argument with the following properties: -- `bindings` returns the bindings object of the specific source. It must have the attributes as a key, and the value can be a `string` or an `object` with arguments. This object contains a `newValue` property with the user's input. -- `clientId` returns a `string` with the current block client ID. -- `context` returns an `object` of the current block context, defined in the `usesContext` property. [More about block context.](https://developer.wordpress.org/block-editor/reference-guides/block-api/block-context/). -- `dispatch` returns an `object` of the store's action creators. [More about dispatch](https://developer.wordpress.org/block-editor/reference-guides/packages/packages-data/#dispatch). -- `select` returns an `object` of a given store's selectors. [More info in their docs.](https://developer.wordpress.org/block-editor/reference-guides/packages/packages-data/#select). +- `bindings` returns the bindings object of the specific source. It must have the attributes as a key, and the value can be a `string` or an `object` with arguments. This object contains a `newValue` property with the user's input. +- `clientId` returns a `string` with the current block client ID. +- `context` returns an `object` of the current block context, defined in the `usesContext` property. [More about block context.](https://developer.wordpress.org/block-editor/reference-guides/block-api/block-context/). +- `dispatch` returns an `object` of the store's action creators. [More about dispatch](https://developer.wordpress.org/block-editor/reference-guides/packages/packages-data/#dispatch). +- `select` returns an `object` of a given store's selectors. [More info in their docs.](https://developer.wordpress.org/block-editor/reference-guides/packages/packages-data/#select). #### getFieldsList @@ -261,44 +436,44 @@ The `getFieldsList` function enables custom sources to appear in the Block Bindi Each field object in the array should have the following properties: -- `label`: `string` that defines the label shown in the dropdown selector. Defaults to the source label if not provided. -- `type`: `string` that defines the attribute value type. It must match the attribute type it binds to; otherwise, it won't appear in the UI. For example, an `id` attribute that accepts only numbers should only display fields that return numeric values. -- `args`: `object` that defines the source arguments that are applied when a user selects the field from the dropdown. +- `label`: `string` that defines the label shown in the dropdown selector. Defaults to the source label if not provided. +- `type`: `string` that defines the attribute value type. It must match the attribute type it binds to; otherwise, it won't appear in the UI. For example, an `id` attribute that accepts only numbers should only display fields that return numeric values. +- `args`: `object` that defines the source arguments that are applied when a user selects the field from the dropdown. Example: ```js registerBlockBindingsSource( { - name: 'my-plugin/custom-fields', - label: 'Custom Fields', - getFieldsList() { - return [ - { - label: 'Author Name', - type: 'string', - args: { - field: 'author_name', - }, - }, - { - label: 'Publication Year', - type: 'string', - args: { - field: 'publication_year', - }, - }, - { - label: 'Page Count', - type: 'number', - args: { - field: 'page_count', - }, - }, - ]; - }, - getValues( { bindings } ) { - // Implementation to retrieve values based on args.field - }, + name: 'my-plugin/custom-fields', + label: 'Custom Fields', + getFieldsList() { + return [ + { + label: 'Author Name', + type: 'string', + args: { + field: 'author_name', + }, + }, + { + label: 'Publication Year', + type: 'string', + args: { + field: 'publication_year', + }, + }, + { + label: 'Page Count', + type: 'number', + args: { + field: 'page_count', + }, + }, + ]; + }, + getValues( { bindings } ) { + // Implementation to retrieve values based on args.field + }, } ); ``` @@ -312,10 +487,8 @@ Check the Date: Wed, 7 Jan 2026 11:06:21 +0100 Subject: [PATCH 6/7] Update docs/reference-guides/block-api/block-bindings.md Co-authored-by: Bernie Reiter <96308+ockham@users.noreply.github.com> --- docs/reference-guides/block-api/block-bindings.md | 1 + 1 file changed, 1 insertion(+) diff --git a/docs/reference-guides/block-api/block-bindings.md b/docs/reference-guides/block-api/block-bindings.md index 578a0a23bde08e..26e6e691009783 100644 --- a/docs/reference-guides/block-api/block-bindings.md +++ b/docs/reference-guides/block-api/block-bindings.md @@ -32,6 +32,7 @@ Right now, not all block attributes are compatible with block bindings. There is | core/button | url, text, linkTarget, rel | | core/navigation-link | url | | core/navigation-submenu | url | +| core/post-date | datetime | ## Core Sources From 01e796c3d56bd6604af5277db05e0d6632a7f6da Mon Sep 17 00:00:00 2001 From: JuanMa Date: Wed, 7 Jan 2026 11:49:28 +0100 Subject: [PATCH 7/7] Refine `core/term-data` documentation: Update examples to include proper HTML structure, clarify context requirements, and enhance notes on attribute binding for better clarity. --- .../block-api/block-bindings.md | 47 ++++++++++--------- 1 file changed, 25 insertions(+), 22 deletions(-) diff --git a/docs/reference-guides/block-api/block-bindings.md b/docs/reference-guides/block-api/block-bindings.md index 26e6e691009783..af57a7107c3b40 100644 --- a/docs/reference-guides/block-api/block-bindings.md +++ b/docs/reference-guides/block-api/block-bindings.md @@ -130,7 +130,7 @@ The `core/term-data` source provides access to taxonomy term data fields when te | `slug` | URL-friendly slug | `category-slug` | | `description` | Term description | `A description of the category` | | `parent` | Parent term ID (hierarchical taxonomies) | `0` | -| `count` | Number of posts in this term | `5` | [2](#9-1) +| `count` | Number of posts in this term | `5` | #### Example Usage @@ -138,11 +138,13 @@ The `core/term-data` source provides access to taxonomy term data fields when te ```html - - -

Category Name

- - +
+ + +

Category Name

+ + +
``` @@ -150,21 +152,22 @@ The `core/term-data` source provides access to taxonomy term data fields when te ```html - - - Tag Name - - +
+ + +

Tag Name

+ + +
``` #### Context Requirements -The `core/term-data` source works in these contexts: +The [`core/term-data`](https://github.com/WordPress/gutenberg/tree/trunk/packages/editor/src/bindings/term-data.js) source works in these contexts: -1. **Term Templates** - Automatically provides context for each term -2. **Navigation Blocks** - Special backwards compatibility handling for `core/navigation-link` and `core/navigation-submenu` -3. **Custom Context** - Any template that provides `termId` and `taxonomy` context +1. **Any block providing term context** - Built-in blocks like [`core/term-template`](https://github.com/WordPress/gutenberg/tree/trunk/packages/block-library/src/term-template), or custom blocks that provide `termId` and `taxonomy` via block context +2. **Navigation Blocks** - Special backwards compatibility handling for `core/navigation-link` and `core/navigation-submenu` (these read from block attributes instead of context) ### core/pattern-overrides @@ -319,17 +322,15 @@ The `block_bindings_supported_attributes_{$block_type}` filter allows developers This filter provides a way to extend or restrict which attributes of a specific block type can be bound to dynamic sources. The attributes registered through this filter will appear as options in the block binding interface. -**Note:** This filter is currently not implemented for pattern overrides. +
This filter has no impact on pattern overrides as they are handled independently.
Example: ```php -// Allow binding the 'className' attribute for paragraph blocks -add_filter( 'block_bindings_supported_attributes_core/paragraph', function( $attributes ) { - $attributes['className'] = array( - 'type' => 'string', - ); - return $attributes; +// Allow binding the 'caption' attribute for image blocks +add_filter( 'block_bindings_supported_attributes_core/image', function( $supported_attributes ) { + $supported_attributes[] = 'caption'; + return $supported_attributes; } ); ``` @@ -338,6 +339,8 @@ add_filter( 'block_bindings_supported_attributes_core/paragraph', function( $att There are a few examples in Core that can be used as reference. - Post Meta. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/block-bindings/post-meta.php) +- Post Data. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/block-bindings/post-data.php) +- Term Data. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/block-bindings/term-data.php) - Pattern overrides. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-includes/block-bindings/pattern-overrides.php) - Twenty Twenty-Five theme. [Source code](https://github.com/WordPress/wordpress-develop/blob/trunk/src/wp-content/themes/twentytwentyfive/functions.php)