Plugin: Remove replace_editor filter, extend core editor

docs/designers-developers/developers/backward-compatibility/deprecations.md

@@ -67,6 +67,13 @@ The Gutenberg project's deprecation policy is intended to support backward compa
 - `window._wpLoadGutenbergEditor` has been removed. Use `window._wpLoadBlockEditor` instead. Note: This is a private API, not intended for public use. It may be removed in the future.
 - The PHP function `gutenberg_get_script_polyfill` has been removed. Use [`wp_get_script_polyfill`](https://developer.wordpress.org/reference/functions/wp_get_script_polyfill/) instead.
 - The PHP function `gutenberg_add_admin_body_class` has been removed. Use the `.block-editor-page` class selector in your stylesheets if you need to scope styles to the block editor screen.
+- The PHP function `gutenberg_init` has been removed.
+- The PHP function `is_gutenberg_page` has been removed. Use [`WP_Screen::is_block_editor`](https://developer.wordpress.org/reference/classes/wp_screen/is_block_editor/) instead.
+- The PHP function `the_gutenberg_project` has been removed.
+- The PHP function `gutenberg_default_post_format_template` has been removed.
+- The PHP function `gutenberg_get_available_image_sizes` has been removed.
+- The PHP function `gutenberg_get_autosave_newer_than_post_save` has been removed.
+- The PHP function `gutenberg_default_post_format_template` has been removed.
 
 ## 4.5.0
 - `Dropdown.refresh()` has been deprecated as the contained `Popover` is now automatically refreshed.

gutenberg.php

@@ -21,32 +21,11 @@
  * The main entry point for the Gutenberg editor. Renders the editor on the
  * wp-admin page for the plugin.
  *
- * The gutenberg and gutenberg__editor classNames are left for backward compatibility.
- *
  * @since 0.1.0
+ * @deprecated 5.2.0
  */
 function the_gutenberg_project() {
-	global $post_type_object;
-	?>
-	<noscript>
-		<div class="error" style="position:absolute;top:32px;z-index:40"><p>
-		<?php
-		printf(
-			/* translators: %s: https://wordpress.org/plugins/classic-editor/ */
-			__( 'The Block Editor requires JavaScript. Please try the <a href="%s">Classic Editor plugin</a>.', 'gutenberg' ),
-			__( 'https://wordpress.org/plugins/classic-editor/', 'gutenberg' )
-		);
-		?>
-		</p></div>
-	</noscript>
-	<div class="block-editor gutenberg">
-		<h1 class="screen-reader-text"><?php echo esc_html( $post_type_object->labels->edit_item ); ?></h1>
-		<div id="editor" class="block-editor__container gutenberg__editor"></div>
-		<div id="metaboxes" class="hidden">
-			<?php the_block_editor_meta_boxes(); ?>
-		</div>
-	</div>
-	<?php
+	_deprecated_function( __FUNCTION__, '5.2.0' );
 }
 
 /**
@@ -64,7 +43,7 @@ function gutenberg_menu() {
 		'Gutenberg',
 		'edit_posts',
 		'gutenberg',
-		'the_gutenberg_project',
+		'',
 		'dashicons-edit'
 	);
 
@@ -104,34 +83,15 @@ function gutenberg_menu() {
 /**
  * Checks whether we're currently loading a Gutenberg page
  *
- * @return boolean Whether Gutenberg is being loaded.
- *
  * @since 3.1.0
+ * @deprecated 5.2.0 WP_Screen::is_block_editor
+ *
+ * @return boolean Whether Gutenberg is being loaded.
  */
 function is_gutenberg_page() {
-	global $post;
-
-	if ( ! is_admin() ) {
-		return false;
-	}
-
-	/*
-	 * There have been reports of specialized loading scenarios where `get_current_screen`
-	 * does not exist. In these cases, it is safe to say we are not loading Gutenberg.
-	 */
-	if ( ! function_exists( 'get_current_screen' ) ) {
-		return false;
-	}
+	_deprecated_function( __FUNCTION__, '5.2.0', 'WP_Screen::is_block_editor' );
 
-	if ( get_current_screen()->base !== 'post' ) {
-		return false;
-	}
-
-	if ( ! use_block_editor_for_post( $post ) ) {
-		return false;
-	}
-
-	return true;
+	return get_current_screen()->is_block_editor();
 }
 
 /**
@@ -182,55 +142,19 @@ function gutenberg_pre_init() {
 	}
 
 	require_once dirname( __FILE__ ) . '/lib/load.php';
-
-	add_filter( 'replace_editor', 'gutenberg_init', 10, 2 );
 }
 
 /**
  * Initialize Gutenberg.
  *
  * Load API functions, register scripts and actions, etc.
  *
- * @param  bool   $return Whether to replace the editor. Used in the `replace_editor` filter.
- * @param  object $post   The post to edit or an auto-draft.
- * @return bool   Whether Gutenberg was initialized.
+ * @deprecated 5.2.0
+ *
+ * @return bool Whether Gutenberg was initialized.
  */
-function gutenberg_init( $return, $post ) {
-	if ( true === $return && current_filter() === 'replace_editor' ) {
-		return $return;
-	}
-
-	if ( ! is_gutenberg_page() ) {
-		return false;
-	}
+function gutenberg_init() {
+	_deprecated_function( __FUNCTION__, '5.2.0' );
 
-	// Instruct WordPress that this is the block editor. Without this, a call
-	// to `is_block_editor()` would yield `false` while editing a post with
-	// Gutenberg.
-	//
-	// [TODO]: This is temporary so long as Gutenberg is implemented to use
-	// `replace_editor`, rather than allow `edit-form-blocks.php` from core to
-	// take effect, where this would otherwise be assigned.
-	get_current_screen()->is_block_editor( true );
-
-	add_action( 'admin_enqueue_scripts', 'gutenberg_editor_scripts_and_styles' );
-	add_filter( 'screen_options_show_screen', '__return_false' );
-
-	/*
-	 * Remove the emoji script as it is incompatible with both React and any
-	 * contenteditable fields.
-	 */
-	remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
-
-	/*
-	 * Ensure meta box functions are available to third-party code;
-	 * includes/meta-boxes is typically loaded from edit-form-advanced.php.
-	 */
-	require_once ABSPATH . 'wp-admin/includes/meta-boxes.php';
-	register_and_do_post_meta_boxes( $post );
-
-	require_once ABSPATH . 'wp-admin/admin-header.php';
-	the_gutenberg_project();
-
-	return true;
+	return get_current_screen()->is_block_editor();
 }