Improve collaborative editing in sync package

lib/experimental/synchronization.php

@@ -22,3 +22,20 @@ function gutenberg_rest_api_init_collaborative_editing() {
 	wp_add_inline_script( 'wp-sync', 'window.__experimentalCollaborativeEditingSecret = "' . $collaborative_editing_secret . '";', 'before' );
 }
 add_action( 'admin_init', 'gutenberg_rest_api_init_collaborative_editing' );
+
+/**
+ * Add support for collaborative editing to some built-in post types.
+ */
+function gutenberg_add_collaborative_editing_post_type_support() {
+	$gutenberg_experiments = get_option( 'gutenberg-experiments' );
+	if ( ! $gutenberg_experiments || ! array_key_exists( 'gutenberg-sync-collaboration', $gutenberg_experiments ) ) {
+		return;
+	}
+
+	foreach ( array( 'page', 'post' ) as $post_type ) {
+		if ( post_type_exists( $post_type ) ) {
+			add_post_type_support( $post_type, 'collaborative-editing' );
+		}
+	}
+}
+add_action( 'init', 'gutenberg_add_collaborative_editing_post_type_support', 10, 0 );

lib/experiments-page.php

@@ -117,12 +117,12 @@ function gutenberg_initialize_experiments_settings() {
 
 	add_settings_field(
 		'gutenberg-sync-collaboration',
-		__( 'Collaboration: add real time editing', 'gutenberg' ),
+		__( 'Collaboration: enable real-time collaboration', 'gutenberg' ),
 		'gutenberg_display_experiment_field',
 		'gutenberg-experiments',
 		'gutenberg_experiments_section',
 		array(
-			'label' => __( 'Enables live collaboration and offline persistence between peers.', 'gutenberg' ),
+			'label' => __( 'Enables real-time collaboration between peers.', 'gutenberg' ),
 			'id'    => 'gutenberg-sync-collaboration',
 		)
 	);

packages/block-editor/src/components/provider/use-block-sync.js

@@ -104,15 +104,25 @@ export default function useBlockSync( {
 		// and so it would already be persisted.
 		__unstableMarkNextChangeAsNotPersistent();
 		if ( clientId ) {
+			const blockName = getBlockName( clientId );
+			const isPostContentBlock = blockName === 'core/post-content';
+
 			// It is important to batch here because otherwise,
 			// as soon as `setHasControlledInnerBlocks` is called
 			// the effect to restore might be triggered
 			// before the actual blocks get set properly in state.
 			registry.batch( () => {
 				setHasControlledInnerBlocks( clientId, true );
-				const storeBlocks = controlledBlocks.map( ( block ) =>
-					cloneBlock( block )
-				);
+
+				// For post-content block children, preserve the
+				// original blocks to maintain UUIDs used for
+				// multi-user collaboration
+				//
+				// Unsure: Why are these blocks being cloned? Do they need to be?
+				const storeBlocks = isPostContentBlock
+					? controlledBlocks
+					: controlledBlocks.map( ( block ) => cloneBlock( block ) );
+
 				if ( subscribedRef.current ) {
 					pendingChangesRef.current.incoming = storeBlocks;
 				}

packages/core-data/package.json

@@ -40,6 +40,7 @@
 		"@wordpress/data": "file:../data",
 		"@wordpress/deprecated": "file:../deprecated",
 		"@wordpress/element": "file:../element",
+		"@wordpress/hooks": "file:../hooks",
 		"@wordpress/html-entities": "file:../html-entities",
 		"@wordpress/i18n": "file:../i18n",
 		"@wordpress/is-shallow-equal": "file:../is-shallow-equal",
@@ -52,6 +53,7 @@
 		"change-case": "^4.1.2",
 		"equivalent-key-map": "^0.2.2",
 		"fast-deep-equal": "^3.1.3",
+		"lib0": "^0.2.99",
 		"memize": "^2.1.0",
 		"uuid": "^9.0.1"
 	},