Real-time collaboration: Add new REST endpoints, setting, and registered post meta

src/wp-admin/includes/schema.php

@@ -563,6 +563,9 @@ function populate_options( array $options = array() ) {
 
 		// 6.9.0
 		'wp_notes_notify'                 => 1,
+
+		// 7.0.0
+		'enable_real_time_collaboration'  => 0,
 	);
 
 	// 3.3.0

src/wp-admin/options-writing.php

@@ -109,6 +109,13 @@
 	</select>
 </td>
 </tr>
+<tr>
+<th scope="row"><label for="enable_real_time_collaboration"><?php _e( 'Collaboration' ); ?></label></th>
+<td>
+	<input name="enable_real_time_collaboration" type="checkbox" id="enable_real_time_collaboration" value="1" <?php checked( '1', get_option( 'enable_real_time_collaboration' ) ); ?> />
+	<label for="enable_real_time_collaboration"><?php _e( 'Enable real-time collaboration' ); ?></label>
+</td>
+</tr>
 <?php
 if ( get_option( 'link_manager_enabled' ) ) :
 	?>

src/wp-admin/options.php

@@ -153,6 +153,7 @@
 		'default_email_category',
 		'default_link_category',
 		'default_post_format',
+		'enable_real_time_collaboration',
 	),
 );
 $allowed_options['misc']    = array();

src/wp-includes/collaboration.php

@@ -0,0 +1,24 @@
+<?php
+/**
+ * Bootstraps collaborative editing.
+ *
+ * @package WordPress
+ * @since 7.0.0
+ */
+
+/**
+ * Injects the real-time collaboration setting into a global variable.
+ *
+ * @since 7.0.0
+ *
+ * @access private
+ */
+function wp_collaboration_inject_setting() {
+	if ( get_option( 'enable_real_time_collaboration' ) ) {
+		wp_add_inline_script(
+			'wp-core-data',
+			'window._wpCollaborationEnabled = true;',
+			'after'
+		);
+	}
+}