Interactivity API: Add getServerState() and getServerContext()

packages/e2e-tests/plugins/interactive-blocks/directive-priorities/view.js

@@ -41,13 +41,13 @@ directive(
 	'test-context',
 	( { context: { Provider }, props: { children } } ) => {
 		executionProof( 'context' );
-		const value = {
+		const client = {
 			[ namespace ]: proxifyState( namespace, {
 				attribute: 'from context',
 				text: 'from context',
 			} ),
 		};
-		return h( Provider, { value }, children );
+		return h( Provider, { value: { client } }, children );
 	},
 	{ priority: 8 }
 );

packages/e2e-tests/plugins/interactive-blocks/get-server-context/block.json

@@ -0,0 +1,15 @@
+{
+	"$schema": "https://schemas.wp.org/trunk/block.json",
+	"apiVersion": 2,
+	"name": "test/get-server-context",
+	"title": "E2E Interactivity tests - getServerContext",
+	"category": "text",
+	"icon": "heart",
+	"description": "",
+	"supports": {
+		"interactivity": true
+	},
+	"textdomain": "e2e-interactivity",
+	"viewScriptModule": "file:./view.js",
+	"render": "file:./render.php"
+}

packages/e2e-tests/plugins/interactive-blocks/get-server-context/render.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * HTML for testing the getServerContext() function.
+ *
+ * @package gutenberg-test-interactive-blocks
+ *
+ * @phpcs:disable VariableAnalysis.CodeAnalysis.VariableAnalysis.UndefinedVariable
+ */
+
+$link1      = $attributes['links']['modified'];
+$link2      = $attributes['links']['newProps'];
+$parent_ctx = $attributes['parentContext'];
+$child_ctx  = $attributes['childContext'];
+?>
+
+<nav
+	data-testid="navigate"
+	data-wp-interactive="test/get-server-context"
+	data-wp-on--click="actions.navigate"
+>
+	<a data-testid="modified" href="<?php echo esc_url( $link1 ); ?>">modified</a>
+	<a data-testid="newProps" href="<?php echo esc_url( $link2 ); ?>">newProps</a>
+</nav>
+
+<div
+	data-wp-interactive="test/get-server-context"
+	data-wp-router-region="server-context"
+	data-wp-watch="callbacks.updateServerContextParent"
+	<?php echo wp_interactivity_data_wp_context( $parent_ctx ); ?>
+>
+	<div
+		data-wp-watch="callbacks.updateServerContextChild"
+		<?php echo wp_interactivity_data_wp_context( $child_ctx ); ?>
+	>
+		<div data-testid="prop" data-wp-text="context.prop"></div>
+		<div data-testid="nested.prop" data-wp-text="context.nested.prop"></div>
+		<div data-testid="newProp" data-wp-text="context.newProp"></div>
+		<div data-testid="nested.newProp" data-wp-text="context.nested.newProp"></div>
+		<div data-testid="inherited.prop" data-wp-text="context.inherited.prop"></div>
+		<div data-testid="inherited.newProp" data-wp-text="context.inherited.newProp"></div>
+
+		<button
+			data-testid="tryToModifyServerContext"
+			<?php echo wp_interactivity_data_wp_context( array( 'result' => 'modify' ) ); ?>
+			data-wp-on--click="actions.attemptModification"
+			data-wp-text="context.result">
+		>
+			modify
+		</button>
+	</div>
+</div>

packages/e2e-tests/plugins/interactive-blocks/get-server-context/view.asset.php

@@ -0,0 +1,9 @@
+<?php return array(
+	'dependencies' => array(
+		'@wordpress/interactivity',
+		array(
+			'id'     => '@wordpress/interactivity-router',
+			'import' => 'dynamic',
+		),
+	),
+);

packages/e2e-tests/plugins/interactive-blocks/get-server-context/view.js

@@ -0,0 +1,46 @@
+/**
+ * WordPress dependencies
+ */
+import { store, getContext, getServerContext } from '@wordpress/interactivity';
+
+store( 'test/get-server-context', {
+	actions: {
+		*navigate( e ) {
+			e.preventDefault();
+			const { actions } = yield import(
+				'@wordpress/interactivity-router'
+			);
+			yield actions.navigate( e.target.href );
+		},
+		attemptModification() {
+			try {
+				getServerContext().prop = 'updated from client';
+				getContext().result = 'unexpectedly modified ❌';
+			} catch ( e ) {
+				getContext().result = 'not modified ✅';
+			}
+		},
+	},
+	callbacks: {
+		updateServerContextParent() {
+			const ctx = getContext();
+			const { prop, newProp, nested, inherited } = getServerContext();
+			ctx.prop = prop;
+			ctx.newProp = newProp;
+			ctx.nested.prop = nested.prop;
+			ctx.nested.newProp = nested.newProp;
+			ctx.inherited.prop = inherited.prop;
+			ctx.inherited.newProp = inherited.newProp;
+		},
+		updateServerContextChild() {
+			const ctx = getContext();
+			const { prop, newProp, nested, inherited } = getServerContext();
+			ctx.prop = prop;
+			ctx.newProp = newProp;
+			ctx.nested.prop = nested.prop;
+			ctx.nested.newProp = nested.newProp;
+			ctx.inherited.prop = inherited.prop;
+			ctx.inherited.newProp = inherited.newProp;
+		},
+	},
+} );

packages/e2e-tests/plugins/interactive-blocks/get-server-state/block.json

@@ -0,0 +1,15 @@
+{
+	"$schema": "https://schemas.wp.org/trunk/block.json",
+	"apiVersion": 2,
+	"name": "test/get-server-state",
+	"title": "E2E Interactivity tests - getServerState",
+	"category": "text",
+	"icon": "heart",
+	"description": "",
+	"supports": {
+		"interactivity": true
+	},
+	"textdomain": "e2e-interactivity",
+	"viewScriptModule": "file:./view.js",
+	"render": "file:./render.php"
+}

packages/e2e-tests/plugins/interactive-blocks/get-server-state/render.php

@@ -0,0 +1,50 @@
+<?php
+/**
+ * HTML for testing the getServerState() function.
+ *
+ * @package gutenberg-test-interactive-blocks
+ *
+ * @phpcs:disable VariableAnalysis.CodeAnalysis.VariableAnalysis.UndefinedVariable
+ */
+
+if ( isset( $attributes['state'] ) ) {
+	wp_interactivity_state( 'test/get-server-state', $attributes['state'] );
+}
+?>
+
+<div
+	data-wp-interactive="test/get-server-state"
+	data-wp-watch="callbacks.updateState"
+>
+	<div data-testid="prop" data-wp-text="state.prop"></div>
+	<div data-testid="nested.prop" data-wp-text="state.nested.prop"></div>
+	<div data-testid="newProp" data-wp-text="state.newProp"></div>
+	<div data-testid="nested.newProp" data-wp-text="state.nested.newProp"></div>
+
+	<button
+		data-testid="tryToModifyServerState"
+		<?php echo wp_interactivity_data_wp_context( array( 'result' => 'modify' ) ); ?>
+		data-wp-on--click="actions.attemptModification"
+		data-wp-text="context.result">
+	>
+		modify
+	</button>
+
+
+	<nav>
+		<?php
+		if ( isset( $attributes['links'] ) ) {
+			foreach ( $attributes['links'] as $key => $link ) {
+				$i = $key += 1;
+				echo <<<HTML
+				<a
+					data-testid="link $i"
+					data-wp-on--click="actions.navigate"
+					href="$link"
+				>link $i</a>
+HTML;
+			}
+		}
+		?>
+	</nav>
+</div>

packages/e2e-tests/plugins/interactive-blocks/get-server-state/view.asset.php

@@ -0,0 +1,9 @@
+<?php return array(
+	'dependencies' => array(
+		'@wordpress/interactivity',
+		array(
+			'id'     => '@wordpress/interactivity-router',
+			'import' => 'dynamic',
+		),
+	),
+);

packages/e2e-tests/plugins/interactive-blocks/get-server-state/view.js

@@ -0,0 +1,33 @@
+/**
+ * WordPress dependencies
+ */
+import { store, getServerState, getContext } from '@wordpress/interactivity';
+
+const { state } = store( 'test/get-server-state', {
+	actions: {
+		*navigate( e ) {
+			e.preventDefault();
+			const { actions } = yield import(
+				'@wordpress/interactivity-router'
+			);
+			yield actions.navigate( e.target.href );
+		},
+		attemptModification() {
+			try {
+				getServerState().prop = 'updated from client';
+				getContext().result = 'unexpectedly modified ❌';
+			} catch ( e ) {
+				getContext().result = 'not modified ✅';
+			}
+		},
+	},
+	callbacks: {
+		updateState() {
+			const { prop, newProp, nested } = getServerState();
+			state.prop = prop;
+			state.newProp = newProp;
+			state.nested.prop = nested.prop;
+			state.nested.newProp = nested.newProp;
+		},
+	},
+} );

packages/interactivity/src/directives.tsx

@@ -142,14 +142,19 @@ export default () => {
 			const defaultEntry = context.find(
 				( { suffix } ) => suffix === 'default'
 			);
-			const inheritedValue = useContext( inheritedContext );
+			const { client: inheritedClient, server: inheritedServer } =
+				useContext( inheritedContext );
 
 			const ns = defaultEntry!.namespace;
-			const currentValue = useRef( proxifyState( ns, {} ) );
+			const client = useRef( proxifyState( ns, {} ) );
+			const server = useRef( proxifyState( ns, {}, { readOnly: true } ) );
 
 			// No change should be made if `defaultEntry` does not exist.
 			const contextStack = useMemo( () => {
-				const result = { ...inheritedValue };
+				const result = {
+					client: { ...inheritedClient },
+					server: { ...inheritedServer },
+				};
 				if ( defaultEntry ) {
 					const { namespace, value } = defaultEntry;
 					// Check that the value is a JSON object. Send a console warning if not.
@@ -159,17 +164,22 @@ export default () => {
 						);
 					}
 					deepMerge(
-						currentValue.current,
+						client.current,
 						deepClone( value ) as object,
 						false
 					);
-					result[ namespace ] = proxifyContext(
-						currentValue.current,
-						inheritedValue[ namespace ]
+					deepMerge( server.current, deepClone( value ) as object );
+					result.client[ namespace ] = proxifyContext(
+						client.current,
+						inheritedClient[ namespace ]
+					);
+					result.server[ namespace ] = proxifyContext(
+						server.current,
+						inheritedServer[ namespace ]
 					);
 				}
 				return result;
-			}, [ defaultEntry, inheritedValue ] );
+			}, [ defaultEntry, inheritedClient, inheritedServer ] );
 
 			return createElement( Provider, { value: contextStack }, children );
 		},
@@ -563,17 +573,24 @@ export default () => {
 					suffix === 'default' ? 'item' : kebabToCamelCase( suffix );
 				const itemContext = proxifyContext(
 					proxifyState( namespace, {} ),
-					inheritedValue[ namespace ]
+					inheritedValue.client[ namespace ]
 				);
 				const mergedContext = {
-					...inheritedValue,
-					[ namespace ]: itemContext,
+					client: {
+						...inheritedValue.client,
+						[ namespace ]: itemContext,
+					},
+					server: { ...inheritedValue.server },
 				};
 
 				// Set the item after proxifying the context.
-				mergedContext[ namespace ][ itemProp ] = item;
+				mergedContext.client[ namespace ][ itemProp ] = item;
 
-				const scope = { ...getScope(), context: mergedContext };
+				const scope = {
+					...getScope(),
+					context: mergedContext.client,
+					serverContext: mergedContext.server,
+				};
 				const key = eachKey
 					? getEvaluate( { scope } )( eachKey[ 0 ] )
 					: item;

packages/interactivity/src/hooks.tsx

@@ -93,7 +93,7 @@ interface DirectivesProps {
 }
 
 // Main context.
-const context = createContext< any >( {} );
+const context = createContext< any >( { client: {}, server: {} } );
 
 // WordPress Directives.
 const directiveCallbacks: Record< string, DirectiveCallback > = {};
@@ -253,7 +253,9 @@ const Directives = ( {
 	// element ref, state and props.
 	const scope = useRef< Scope >( {} as Scope ).current;
 	scope.evaluate = useCallback( getEvaluate( { scope } ), [] );
-	scope.context = useContext( context );
+	const { client, server } = useContext( context );
+	scope.context = client;
+	scope.serverContext = server;
 	/* eslint-disable react-hooks/rules-of-hooks */
 	scope.ref = previousScope?.ref || useRef( null );
 	/* eslint-enable react-hooks/rules-of-hooks */

packages/interactivity/src/index.ts

@@ -16,8 +16,8 @@ import { getNamespace } from './namespaces';
 import { parseServerData, populateServerData } from './store';
 import { proxifyState } from './proxies';
 
-export { store, getConfig } from './store';
-export { getContext, getElement } from './scopes';
+export { store, getConfig, getServerState } from './store';
+export { getContext, getServerContext, getElement } from './scopes';
 export {
 	withScope,
 	useWatch,