Block Bindings: Improve how the context needed by sources is extended in the editor

packages/block-editor/src/hooks/use-bindings-attributes.js

@@ -4,13 +4,14 @@
 import { store as blocksStore } from '@wordpress/blocks';
 import { createHigherOrderComponent } from '@wordpress/compose';
 import { useRegistry, useSelect } from '@wordpress/data';
-import { useCallback, useMemo } from '@wordpress/element';
+import { useCallback, useMemo, useContext } from '@wordpress/element';
 import { addFilter } from '@wordpress/hooks';
 
 /**
  * Internal dependencies
  */
 import { unlock } from '../lock-unlock';
+import BlockContext from '../components/block-context';
 
 /** @typedef {import('@wordpress/compose').WPHigherOrderComponent} WPHigherOrderComponent */
 /** @typedef {import('@wordpress/blocks').WPBlockSettings} WPBlockSettings */
@@ -93,10 +94,11 @@ export function canBindAttribute( blockName, attributeName ) {
 export const withBlockBindingSupport = createHigherOrderComponent(
 	( BlockEdit ) => ( props ) => {
 		const registry = useRegistry();
+		const blockContext = useContext( BlockContext );
 		const sources = useSelect( ( select ) =>
 			unlock( select( blocksStore ) ).getAllBlockBindingsSources()
 		);
-		const { name, clientId, context } = props;
+		const { name, clientId } = props;
 		const hasParentPattern = !! props.context[ 'pattern/overrides' ];
 		const hasPatternOverridesDefaultBinding =
 			props.attributes.metadata?.bindings?.[ DEFAULT_ATTRIBUTE ]
@@ -145,6 +147,15 @@ export const withBlockBindingSupport = createHigherOrderComponent(
 
 			if ( blockBindingsBySource.size ) {
 				for ( const [ source, bindings ] of blockBindingsBySource ) {
+					// Populate context.
+					const context = {};
+
+					if ( source.usesContext?.length ) {
+						for ( const key of source.usesContext ) {
+							context[ key ] = blockContext[ key ];
+						}
+					}
+
 					// Get values in batch if the source supports it.
 					const values = source.getValues( {
 						registry,
@@ -177,7 +188,7 @@ export const withBlockBindingSupport = createHigherOrderComponent(
 			}
 
 			return attributes;
-		}, [ blockBindings, name, clientId, context, registry, sources ] );
+		}, [ blockBindings, name, clientId, blockContext, registry, sources ] );
 
 		const { setAttributes } = props;
 
@@ -223,6 +234,15 @@ export const withBlockBindingSupport = createHigherOrderComponent(
 							source,
 							bindings,
 						] of blockBindingsBySource ) {
+							// Populate context.
+							const context = {};
+
+							if ( source.usesContext?.length ) {
+								for ( const key of source.usesContext ) {
+									context[ key ] = blockContext[ key ];
+								}
+							}
+
 							source.setValues( {
 								registry,
 								context,
@@ -255,7 +275,7 @@ export const withBlockBindingSupport = createHigherOrderComponent(
 				blockBindings,
 				name,
 				clientId,
-				context,
+				blockContext,
 				setAttributes,
 				sources,
 				hasPatternOverridesDefaultBinding,

packages/blocks/src/api/registration.js

@@ -770,6 +770,7 @@ export const unregisterBlockVariation = ( blockName, variationName ) => {
  * @param {Object}   source                    Properties of the source to be registered.
  * @param {string}   source.name               The unique and machine-readable name.
  * @param {string}   [source.label]            Human-readable label.
+ * @param {Array}    [source.usesContext]      Array of context needed by the source only in the editor.
  * @param {Function} [source.getValues]        Function to get the values from the source.
  * @param {Function} [source.setValues]        Function to update multiple values connected to the source.
  * @param {Function} [source.getPlaceholder]   Function to get the placeholder when the value is undefined.
@@ -794,6 +795,7 @@ export const registerBlockBindingsSource = ( source ) => {
 	const {
 		name,
 		label,
+		usesContext,
 		getValues,
 		setValues,
 		getPlaceholder,
@@ -867,6 +869,12 @@ export const registerBlockBindingsSource = ( source ) => {
 		return;
 	}
 
+	// Check the `usesContext` property is correct.
+	if ( usesContext && ! Array.isArray( usesContext ) ) {
+		warning( 'Block bindings source usesContext must be an array.' );
+		return;
+	}
+
 	// Check the `getValues` property is correct.
 	if ( getValues && typeof getValues !== 'function' ) {
 		warning( 'Block bindings source getValues must be a function.' );

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

@@ -1513,8 +1513,10 @@ describe( 'blocks', () => {
 		} );
 
 		it( 'should not override label from the server', () => {
-			// Simulate bootstrapping a source from the server registration.
-			registerBlockBindingsSource( {
+			// Bootstrap source from the server.
+			unlock(
+				dispatch( blocksStore )
+			).addBootstrappedBlockBindingsSource( {
 				name: 'core/server',
 				label: 'Server label',
 			} );
@@ -1528,6 +1530,80 @@ describe( 'blocks', () => {
 			);
 		} );
 
+		// Check the `usesContext` array is correct.
+		it( 'should reject invalid usesContext property', () => {
+			registerBlockBindingsSource( {
+				name: 'core/testing',
+				label: 'testing',
+				usesContext: 'should be an array',
+			} );
+			expect( console ).toHaveWarnedWith(
+				'Block bindings source usesContext must be an array.'
+			);
+		} );
+
+		it( 'should add usesContext when only defined in the server', () => {
+			// Bootstrap source from the server.
+			unlock(
+				dispatch( blocksStore )
+			).addBootstrappedBlockBindingsSource( {
+				name: 'core/testing',
+				label: 'testing',
+				usesContext: [ 'postId', 'postType' ],
+			} );
+			// Register source in the client without usesContext.
+			registerBlockBindingsSource( {
+				name: 'core/testing',
+				getValue: () => 'value',
+			} );
+			const source = getBlockBindingsSource( 'core/testing' );
+			unregisterBlockBindingsSource( 'core/testing' );
+			expect( source.usesContext ).toEqual( [ 'postId', 'postType' ] );
+		} );
+
+		it( 'should add usesContext when only defined in the client', () => {
+			// Bootstrap source from the server.
+			unlock(
+				dispatch( blocksStore )
+			).addBootstrappedBlockBindingsSource( {
+				name: 'core/testing',
+				label: 'testing',
+			} );
+			// Register source in the client with usesContext.
+			registerBlockBindingsSource( {
+				name: 'core/testing',
+				usesContext: [ 'postId', 'postType' ],
+				getValue: () => 'value',
+			} );
+			const source = getBlockBindingsSource( 'core/testing' );
+			unregisterBlockBindingsSource( 'core/testing' );
+			expect( source.usesContext ).toEqual( [ 'postId', 'postType' ] );
+		} );
+
+		it( 'should merge usesContext from server and client without duplicates', () => {
+			// Bootstrap source from the server.
+			unlock(
+				dispatch( blocksStore )
+			).addBootstrappedBlockBindingsSource( {
+				name: 'core/testing',
+				label: 'testing',
+				usesContext: [ 'postId', 'postType' ],
+			} );
+			// Register source in the client with usesContext.
+			registerBlockBindingsSource( {
+				name: 'core/testing',
+				usesContext: [ 'postType', 'clientContext' ],
+				getValue: () => 'value',
+			} );
+			const source = getBlockBindingsSource( 'core/testing' );
+			unregisterBlockBindingsSource( 'core/testing' );
+			expect( source.usesContext ).toEqual( [
+				'postId',
+				'postType',
+				'clientContext',
+			] );
+		} );
+
 		// Check the `getValues` callback is correct.
 		it( 'should reject invalid getValues callback', () => {
 			registerBlockBindingsSource( {
@@ -1584,6 +1660,7 @@ describe( 'blocks', () => {
 		it( 'should register a valid source', () => {
 			const sourceProperties = {
 				label: 'Valid Source',
+				usesContext: [ 'postId' ],
 				getValues: () => 'value',
 				setValues: () => 'new values',
 				getPlaceholder: () => 'placeholder',
@@ -1605,6 +1682,7 @@ describe( 'blocks', () => {
 				label: 'Valid Source',
 			} );
 			const source = getBlockBindingsSource( 'core/valid-source' );
+			expect( source.usesContext ).toBeUndefined();
 			expect( source.getValues ).toBeUndefined();
 			expect( source.setValues ).toBeUndefined();
 			expect( source.getPlaceholder ).toBeUndefined();

packages/blocks/src/store/private-actions.js

@@ -51,6 +51,7 @@ export function addBlockBindingsSource( source ) {
 		type: 'ADD_BLOCK_BINDINGS_SOURCE',
 		name: source.name,
 		label: source.label,
+		usesContext: source.usesContext,
 		getValues: source.getValues,
 		setValues: source.setValues,
 		getPlaceholder: source.getPlaceholder,

packages/blocks/src/store/reducer.js

@@ -374,11 +374,23 @@ export function collections( state = {}, action ) {
 export function blockBindingsSources( state = {}, action ) {
 	switch ( action.type ) {
 		case 'ADD_BLOCK_BINDINGS_SOURCE':
+			// Merge usesContext with existing values, potentially defined in the server registration.
+			let mergedUsesContext = [
+				...( state[ action.name ]?.usesContext || [] ),
+				...( action.usesContext || [] ),
+			];
+			// Remove duplicates.
+			mergedUsesContext =
+				mergedUsesContext.length > 0
+					? [ ...new Set( mergedUsesContext ) ]
+					: undefined;
+
 			return {
 				...state,
 				[ action.name ]: {
 					// Don't override the label if it's already set.
 					label: state[ action.name ]?.label || action.label,
+					usesContext: mergedUsesContext,
 					getValues: action.getValues,
 					setValues: action.setValues,
 					getPlaceholder: action.getPlaceholder,