Block Hooks: Set ignoredHookedBlocks metada attr upon insertion

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.
  *