Footnotes: use core’s meta revisioning if available

packages/block-library/src/footnotes/index.php

@@ -9,6 +9,7 @@
  * Renders the `core/footnotes` block on the server.
  *
  * @since 6.3.0
+ * @since 6.4.0 Core added post meta revisions, so this is no longer needed.
  *
  * @param array    $attributes Block attributes.
  * @param string   $content    Block default content.
@@ -68,9 +69,10 @@ function register_block_core_footnotes() {
 			$post_type,
 			'footnotes',
 			array(
-				'show_in_rest' => true,
-				'single'       => true,
-				'type'         => 'string',
+				'show_in_rest'      => true,
+				'single'            => true,
+				'type'              => 'string',
+				'revisions_enabled' => true,
 			)
 		);
 	}
@@ -87,6 +89,7 @@ function register_block_core_footnotes() {
  * Saves the footnotes meta value to the revision.
  *
  * @since 6.3.0
+ * @since 6.4.0 Core added post meta revisions, so this is no longer needed.
  *
  * @param int $revision_id The revision ID.
  */
@@ -102,12 +105,15 @@ function wp_save_footnotes_meta( $revision_id ) {
 		}
 	}
 }
-add_action( 'wp_after_insert_post', 'wp_save_footnotes_meta' );
+if ( ! function_exists( 'wp_post_revision_meta_keys' ) ) {
+	add_action( 'wp_after_insert_post', 'wp_save_footnotes_meta' );
+}
 
 /**
  * Keeps track of the revision ID for "rest_after_insert_{$post_type}".
  *
  * @since 6.3.0
+ * @since 6.4.0 Core added post meta revisions, so this is no longer needed.
  *
  * @global int $wp_temporary_footnote_revision_id The footnote revision ID.
  *
@@ -117,7 +123,9 @@ function wp_keep_footnotes_revision_id( $revision_id ) {
 	global $wp_temporary_footnote_revision_id;
 	$wp_temporary_footnote_revision_id = $revision_id;
 }
-add_action( '_wp_put_post_revision', 'wp_keep_footnotes_revision_id' );
+if ( ! function_exists( 'wp_post_revision_meta_keys' ) ) {
+	add_action( '_wp_put_post_revision', 'wp_keep_footnotes_revision_id' );
+}
 
 /**
  * This is a specific fix for the REST API. The REST API doesn't update
@@ -131,6 +139,7 @@ function wp_keep_footnotes_revision_id( $revision_id ) {
  * `"rest_after_insert_{$post_type}"` action.
  *
  * @since 6.3.0
+ * @since 6.4.0 Core added post meta revisions, so this is no longer needed.
  *
  * @global int $wp_temporary_footnote_revision_id The footnote revision ID.
  *
@@ -160,13 +169,16 @@ function wp_add_footnotes_revisions_to_post_meta( $post ) {
 	}
 }
 
-add_action( 'rest_after_insert_post', 'wp_add_footnotes_revisions_to_post_meta' );
-add_action( 'rest_after_insert_page', 'wp_add_footnotes_revisions_to_post_meta' );
+if ( ! function_exists( 'wp_post_revision_meta_keys' ) ) {
+	add_action( 'rest_after_insert_post', 'wp_add_footnotes_revisions_to_post_meta' );
+	add_action( 'rest_after_insert_page', 'wp_add_footnotes_revisions_to_post_meta' );
+}
 
 /**
  * Restores the footnotes meta value from the revision.
  *
  * @since 6.3.0
+ * @since 6.4.0 Core added post meta revisions, so this is no longer needed.
  *
  * @param int $post_id     The post ID.
  * @param int $revision_id The revision ID.
@@ -180,10 +192,12 @@ function wp_restore_footnotes_from_revision( $post_id, $revision_id ) {
 		delete_post_meta( $post_id, 'footnotes' );
 	}
 }
-add_action( 'wp_restore_post_revision', 'wp_restore_footnotes_from_revision', 10, 2 );
+if ( ! function_exists( 'wp_post_revision_meta_keys' ) ) {
+	add_action( 'wp_restore_post_revision', 'wp_restore_footnotes_from_revision', 10, 2 );
+}
 
 /**
- * Adds the footnotes field to the revision.
+ * Adds the footnotes field to the revisions display.
  *
  * @since 6.3.0
  *
@@ -197,7 +211,7 @@ function wp_add_footnotes_to_revision( $fields ) {
 add_filter( '_wp_post_revision_fields', 'wp_add_footnotes_to_revision' );
 
 /**
- * Gets the footnotes field from the revision.
+ * Gets the footnotes field from the revision for the revisions screen.
  *
  * @since 6.3.0
  *
@@ -218,6 +232,7 @@ function wp_get_footnotes_from_revision( $revision_field, $field, $revision ) {
  * `_wp_put_post_revision` when it creates a new autosave.
  *
  * @since 6.3.0
+ * @since 6.4.0 Core added post meta revisions, so this is no longer needed.
  *
  * @param int|array $autosave The autosave ID or array.
  */
@@ -242,13 +257,17 @@ function _wp_rest_api_autosave_meta( $autosave ) {
 		return;
 	}
 
-	update_post_meta( $id, 'footnotes', wp_slash( $body['meta']['footnotes'] ) );
+	// Can't use update_post_meta() because it doesn't allow revisions.
+	update_metadata( 'post', $id, 'footnotes', wp_slash( $body['meta']['footnotes'] ) );
+}
+
+if ( ! function_exists( 'wp_post_revision_meta_keys' ) ) {
+	// See https://github.com/WordPress/wordpress-develop/blob/2103cb9966e57d452c94218bbc3171579b536a40/src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php#L391C1-L391C1.
+	add_action( 'wp_creating_autosave', '_wp_rest_api_autosave_meta' );
+	// See https://github.com/WordPress/wordpress-develop/blob/2103cb9966e57d452c94218bbc3171579b536a40/src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php#L398.
+	// Then https://github.com/WordPress/wordpress-develop/blob/2103cb9966e57d452c94218bbc3171579b536a40/src/wp-includes/revision.php#L367.
+	add_action( '_wp_put_post_revision', '_wp_rest_api_autosave_meta' );
 }
-// See https://github.com/WordPress/wordpress-develop/blob/2103cb9966e57d452c94218bbc3171579b536a40/src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php#L391C1-L391C1.
-add_action( 'wp_creating_autosave', '_wp_rest_api_autosave_meta' );
-// See https://github.com/WordPress/wordpress-develop/blob/2103cb9966e57d452c94218bbc3171579b536a40/src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php#L398.
-// Then https://github.com/WordPress/wordpress-develop/blob/2103cb9966e57d452c94218bbc3171579b536a40/src/wp-includes/revision.php#L367.
-add_action( '_wp_put_post_revision', '_wp_rest_api_autosave_meta' );
 
 /**
  * This is a workaround for the autosave endpoint returning early if the
@@ -261,6 +280,7 @@ function _wp_rest_api_autosave_meta( $autosave ) {
  * course, this is temporary fix.
  *
  * @since 6.3.0
+ * @since 6.4.0 Core added post meta revisions, so this is no longer needed.
  *
  * @param WP_Post         $prepared_post The prepared post object.
  * @param WP_REST_Request $request       The request object.
@@ -282,5 +302,6 @@ function _wp_rest_api_force_autosave_difference( $prepared_post, $request ) {
 	$prepared_post->footnotes = '[]';
 	return $prepared_post;
 }
-
-add_filter( 'rest_pre_insert_post', '_wp_rest_api_force_autosave_difference', 10, 2 );
+if ( ! function_exists( 'wp_post_revision_meta_keys' ) ) {
+	add_filter( 'rest_pre_insert_post', '_wp_rest_api_force_autosave_difference', 10, 2 );
+}

test/e2e/specs/editor/various/footnotes.spec.js

@@ -348,6 +348,7 @@ test.describe( 'Footnotes', () => {
 
 		await previewPage.close();
 		await editorPage.bringToFront();
+		await editor.canvas.click( 'p:text("first paragraph")' );
 
 		// Open revisions.
 		await editor.openDocumentSettingsSidebar();
@@ -421,5 +422,23 @@ test.describe( 'Footnotes', () => {
 		await expect(
 			previewPage2.locator( 'ol.wp-block-footnotes li' )
 		).toHaveText( '123″  ↩︎' );
+		/*
+	These tests won't pass until https://core.trac.wordpress.org/ticket/20564 is committed
+		// Verify that the published post is unchanged.
+		// Navigate to the published post.
+		await previewPage2.close();
+		await editorPage.bringToFront();
+		await editor.openDocumentSettingsSidebar();
+		await page
+			.getByRole( 'region', { name: 'Editor settings' } )
+			.getByRole( 'button', { name: 'Post' } )
+			.click();
+		await page.locator( 'a:text("View Post")' ).click();
+
+		// Verify that the published post footnote still says "1".
+		await expect( page.locator( 'ol.wp-block-footnotes li' ) ).toHaveText(
+			'1 ↩︎'
+		);
+	*/
 	} );
 } );