Block Hooks: Set ignoredHookedBlocks metada attr upon insertion (#58553)

In WP 6.5, we'll be enabling insertion of hooked blocks into modified templates/parts/patterns. This is implemented by adding a `metadata.ignoredHookedBlocks` attribute to the hooked block's anchor block upon editing.

As a consequence, upon insertion of an anchor block, this attribute also needs to be added to that newly inserted instance.

_A note on UX: It could be argued that ideally, insertion of a new anchor block should cause its hooked blocks to be inserted alongside with it. This could be a future addition but seems to be a bit more complicated to do. Regardless, the `metadata.ignoredHookedBlocks` attribute also would need to be set in that case, in order to avoid double insertion -- meaning that adding that attribute is required as a baseline anyway._

Co-authored-by: ockham <bernhard-reiter@git.wordpress.org>
Co-authored-by: gziolo <gziolo@git.wordpress.org>

docs/reference-guides/data/data-core-blocks.md

@@ -504,6 +504,54 @@ _Returns_
 
 -   `string?`: Name of the block for handling the grouping of blocks.
 
+### getHookedBlocks
+
+Returns the hooked blocks for a given anchor block.
+
+Given an anchor block name, returns an object whose keys are relative positions, and whose values are arrays of block names that are hooked to the anchor block at that relative position.
+
+_Usage_
+
+```js
+import { store as blocksStore } from '@wordpress/blocks';
+import { useSelect } from '@wordpress/data';
+
+const ExampleComponent = () => {
+	const hookedBlockNames = useSelect(
+		( select ) =>
+			select( blocksStore ).getHookedBlocks( 'core/navigation' ),
+		[]
+	);
+
+	return (
+		<ul>
+			{ Object.keys( hookedBlockNames ).length &&
+				Object.keys( hookedBlockNames ).map( ( relativePosition ) => (
+					<li key={ relativePosition }>
+						{ relativePosition }>
+						<ul>
+							{ hookedBlockNames[ relativePosition ].map(
+								( hookedBlock ) => (
+									<li key={ hookedBlock }>{ hookedBlock }</li>
+								)
+							) }
+						</ul>
+					</li>
+				) ) }
+		</ul>
+	);
+};
+```
+
+_Parameters_
+
+-   _state_ `Object`: Data state.
+-   _blockName_ `string`: Anchor block type name.
+
+_Returns_
+
+-   `Object`: Lists of hooked block names for each relative position.
+
 ### getUnregisteredFallbackBlockName
 
 Returns the name of the block for handling unregistered blocks.

packages/block-editor/src/store/selectors.js

@@ -10,6 +10,7 @@ import {
 	getBlockType,
 	getBlockTypes,
 	getBlockVariations,
+	getHookedBlocks,
 	hasBlockSupport,
 	getPossibleBlockTransformations,
 	parse,
@@ -1936,9 +1937,16 @@ const buildBlockTypeItem =
 			blockType.name,
 			'inserter'
 		);
+
+		const ignoredHookedBlocks = [
+			...new Set( Object.values( getHookedBlocks( id ) ).flat() ),
+		];
+
 		return {
 			...blockItemBase,
-			initialAttributes: {},
+			initialAttributes: ignoredHookedBlocks.length
+				? { metadata: { ignoredHookedBlocks } }
+				: {},
 			description: blockType.description,
 			category: blockType.category,
 			keywords: blockType.keywords,

packages/blocks/README.md

@@ -234,6 +234,20 @@ _Returns_
 
 -   `?string`: Block name.
 
+### getHookedBlocks
+
+Returns the hooked blocks for a given anchor block.
+
+Given an anchor block name, returns an object whose keys are relative positions, and whose values are arrays of block names that are hooked to the anchor block at that relative position.
+
+_Parameters_
+
+-   _name_ `string`: Anchor block name.
+
+_Returns_
+
+-   `Object`: Lists of hooked block names for each relative position.
+
 ### getPhrasingContentSchema
 
 Undocumented declaration.

packages/blocks/src/api/index.js

@@ -124,6 +124,7 @@ export {
 	getBlockTypes,
 	getBlockSupport,
 	hasBlockSupport,
+	getHookedBlocks,
 	getBlockVariations,
 	isReusableBlock,
 	isTemplatePart,

packages/blocks/src/api/registration.js

@@ -550,6 +550,21 @@ export function hasBlockSupport( nameOrType, feature, defaultSupports ) {
 	);
 }
 
+/**
+ * Returns the hooked blocks for a given anchor block.
+ *
+ * Given an anchor block name, returns an object whose keys are relative positions,
+ * and whose values are arrays of block names that are hooked to the anchor block
+ * at that relative position.
+ *
+ * @param {string} name Anchor block name.
+ *
+ * @return {Object} Lists of hooked block names for each relative position.
+ */
+export function getHookedBlocks( name ) {
+	return select( blocksStore ).getHookedBlocks( name );
+}
+
 /**
  * Determines whether or not the given block is a reusable block. This is a
  * special block type that is used to point to a global block stored via the

packages/blocks/src/api/templates.js

@@ -8,7 +8,7 @@ import { renderToString } from '@wordpress/element';
  */
 import { convertLegacyBlockNameAndAttributes } from './parser/convert-legacy-block';
 import { createBlock } from './factory';
-import { getBlockType } from './registration';
+import { getBlockType, getHookedBlocks } from './registration';
 
 /**
  * Checks whether a list of blocks matches a template by comparing the block names.
@@ -115,6 +115,35 @@ export function synchronizeBlocksWithTemplate( blocks = [], template ) {
 					normalizedAttributes
 				);
 
+			const ignoredHookedBlocks = [
+				...new Set(
+					Object.values( getHookedBlocks( blockName ) ).flat()
+				),
+			];
+
+			if ( ignoredHookedBlocks.length ) {
+				const { metadata = {}, ...otherAttributes } = blockAttributes;
+				const {
+					ignoredHookedBlocks: ignoredHookedBlocksFromTemplate = [],
+					...otherMetadata
+				} = metadata;
+
+				const newIgnoredHookedBlocks = [
+					...new Set( [
+						...ignoredHookedBlocks,
+						...ignoredHookedBlocksFromTemplate,
+					] ),
+				];
+
+				blockAttributes = {
+					metadata: {
+						ignoredHookedBlocks: newIgnoredHookedBlocks,
+						...otherMetadata,
+					},
+					...otherAttributes,
+				};
+			}
+
 			// If a Block is undefined at this point, use the core/missing block as
 			// a placeholder for a better user experience.
 			if ( undefined === getBlockType( blockName ) ) {

packages/blocks/src/api/test/templates.js

@@ -28,7 +28,11 @@ describe( 'templates', () => {
 
 	beforeEach( () => {
 		registerBlockType( 'core/test-block', {
-			attributes: {},
+			attributes: {
+				metadata: {
+					type: 'object',
+				},
+			},
 			save: noop,
 			category: 'text',
 			title: 'test block',
@@ -132,6 +136,80 @@ describe( 'templates', () => {
 			] );
 		} );
 
+		it( 'should set ignoredHookedBlocks metadata if a block has hooked blocks', () => {
+			registerBlockType( 'core/hooked-block', {
+				attributes: {},
+				save: noop,
+				category: 'text',
+				title: 'hooked block',
+				blockHooks: { 'core/test-block': 'after' },
+			} );
+
+			const template = [
+				[ 'core/test-block' ],
+				[ 'core/test-block-2' ],
+				[ 'core/test-block-2' ],
+			];
+			const blockList = [];
+
+			expect(
+				synchronizeBlocksWithTemplate( blockList, template )
+			).toMatchObject( [
+				{
+					name: 'core/test-block',
+					attributes: {
+						metadata: {
+							ignoredHookedBlocks: [ 'core/hooked-block' ],
+						},
+					},
+				},
+				{ name: 'core/test-block-2' },
+				{ name: 'core/test-block-2' },
+			] );
+		} );
+
+		it( 'retains previously set ignoredHookedBlocks metadata', () => {
+			registerBlockType( 'core/hooked-block', {
+				attributes: {},
+				save: noop,
+				category: 'text',
+				title: 'hooked block',
+				blockHooks: { 'core/test-block': 'after' },
+			} );
+
+			const template = [
+				[
+					'core/test-block',
+					{
+						metadata: {
+							ignoredHookedBlocks: [ 'core/other-hooked-block' ],
+						},
+					},
+				],
+				[ 'core/test-block-2' ],
+				[ 'core/test-block-2' ],
+			];
+			const blockList = [];
+
+			expect(
+				synchronizeBlocksWithTemplate( blockList, template )
+			).toMatchObject( [
+				{
+					name: 'core/test-block',
+					attributes: {
+						metadata: {
+							ignoredHookedBlocks: [
+								'core/hooked-block',
+								'core/other-hooked-block',
+							],
+						},
+					},
+				},
+				{ name: 'core/test-block-2' },
+				{ name: 'core/test-block-2' },
+			] );
+		} );
+
 		it( 'should create nested blocks', () => {
 			const template = [
 				[ 'core/test-block', {}, [ [ 'core/test-block-2' ] ] ],

packages/blocks/src/store/selectors.js

@@ -106,6 +106,68 @@ export function getBlockType( state, name ) {
 	return state.blockTypes[ name ];
 }
 
+/**
+ * Returns the hooked blocks for a given anchor block.
+ *
+ * Given an anchor block name, returns an object whose keys are relative positions,
+ * and whose values are arrays of block names that are hooked to the anchor block
+ * at that relative position.
+ *
+ * @param {Object} state     Data state.
+ * @param {string} blockName Anchor block type name.
+ *
+ * @example
+ * ```js
+ * import { store as blocksStore } from '@wordpress/blocks';
+ * import { useSelect } from '@wordpress/data';
+ *
+ * const ExampleComponent = () => {
+ *     const hookedBlockNames = useSelect( ( select ) =>
+ *         select( blocksStore ).getHookedBlocks( 'core/navigation' ),
+ *         []
+ *     );
+ *
+ *     return (
+ *         <ul>
+ *             { Object.keys( hookedBlockNames ).length &&
+ *                 Object.keys( hookedBlockNames ).map( ( relativePosition ) => (
+ *                     <li key={ relativePosition }>{ relativePosition }>
+ *                         <ul>
+ *                             { hookedBlockNames[ relativePosition ].map( ( hookedBlock ) => (
+ *                                 <li key={ hookedBlock }>{ hookedBlock }</li>
+ *                             ) ) }
+ *                         </ul>
+ *                     </li>
+ *             ) ) }
+ *         </ul>
+ *     );
+ * };
+ * ```
+ *
+ * @return {Object} Lists of hooked block names for each relative position.
+ */
+export const getHookedBlocks = createSelector(
+	( state, blockName ) => {
+		const hookedBlockTypes = getBlockTypes( state ).filter(
+			( { blockHooks } ) => blockHooks && blockName in blockHooks
+		);
+
+		let hookedBlocks = {};
+		for ( const blockType of hookedBlockTypes ) {
+			const relativePosition = blockType.blockHooks[ blockName ];
+			hookedBlocks = {
+				...hookedBlocks,
+				[ relativePosition ]: [
+					...( hookedBlocks[ relativePosition ] ?? [] ),
+					blockType.name,
+				],
+			};
+		}
+		return hookedBlocks;
+	},
+	( state ) => [ state.blockTypes ]
+);
+
 /**
  * Returns block styles by block name.
  *