<form method="POST">
    <h3>Editing: edit-form-blocks.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php
/**
 * The block editor page.
 *
 * @since 5.0.0
 *
 * @package WordPress
 * @subpackage Administration
 */

// Don't load directly.
if ( ! defined( 'ABSPATH' ) ) {
	die( '-1' );
}

/**
 * @global string       $post_type        Global post type.
 * @global WP_Post_Type $post_type_object Global post type object.
 * @global WP_Post      $post             Global post object.
 * @global string       $title            The title of the current screen.
 * @global array        $wp_meta_boxes    Global meta box state.
 */
global $post_type, $post_type_object, $post, $title, $wp_meta_boxes;

$block_editor_context = new WP_Block_Editor_Context( array( 'post' =&gt; $post ) );

// Flag that we're loading the block editor.
$current_screen = get_current_screen();
$current_screen-&gt;is_block_editor( true );

// Default to is-fullscreen-mode to avoid jumps in the UI.
add_filter(
	'admin_body_class',
	static function ( $classes ) {
		return &quot;$classes is-fullscreen-mode&quot;;
	}
);

/*
 * Emoji replacement is disabled for now, until it plays nicely with React.
 */
remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );

/*
 * Block editor implements its own Options menu for toggling Document Panels.
 */
add_filter( 'screen_options_show_screen', '__return_false' );

wp_enqueue_script( 'heartbeat' );
wp_enqueue_script( 'wp-edit-post' );

$rest_path = rest_get_route_for_post( $post );

$active_theme                   = get_stylesheet();
$global_styles_endpoint_context = current_user_can( 'edit_theme_options' ) ? 'edit' : 'view';
$template_lookup_slug           = 'page' === $post-&gt;post_type ? 'page' : 'single-' . $post-&gt;post_type;
if ( ! empty( $post-&gt;post_name ) ) {
	$template_lookup_slug .= '-' . $post-&gt;post_name;
}
// Preload common data.
$preload_paths = array(
	'/wp/v2/types?context=view',
	'/wp/v2/taxonomies?context=view',
	add_query_arg( 'context', 'edit', $rest_path ),
	sprintf( '/wp/v2/types/%s?context=edit', $post_type ),
	'/wp/v2/users/me',
	array( rest_get_route_for_post_type_items( 'attachment' ), 'OPTIONS' ),
	array( rest_get_route_for_post_type_items( 'page' ), 'OPTIONS' ),
	array( rest_get_route_for_post_type_items( 'wp_block' ), 'OPTIONS' ),
	array( rest_get_route_for_post_type_items( 'wp_template' ), 'OPTIONS' ),
	sprintf( '%s/autosaves?context=edit', $rest_path ),
	'/wp/v2/settings',
	array( '/wp/v2/settings', 'OPTIONS' ),
	'/wp/v2/global-styles/themes/' . $active_theme . '?context=view',
	'/wp/v2/global-styles/themes/' . $active_theme . '/variations?context=view',
	'/wp/v2/themes?context=edit&amp;status=active',
	array( '/wp/v2/global-styles/' . WP_Theme_JSON_Resolver::get_user_global_styles_post_id(), 'OPTIONS' ),
	/*
	 * Preload the global styles path with the correct context based on user caps.
	 * NOTE: There is an equivalent conditional check in the client-side code to fetch
	 * the global styles entity using the appropriate context value.
	 * See the call to `canUser()`, under `useGlobalStylesUserConfig()` in `packages/edit-site/src/components/use-global-styles-user-config/index.js`.
	 * Please ensure that the equivalent check is kept in sync with this preload path.
	 */
	'/wp/v2/global-styles/' . WP_Theme_JSON_Resolver::get_user_global_styles_post_id() . '?context=' . $global_styles_endpoint_context,
	// Used by getBlockPatternCategories in useBlockEditorSettings.
	'/wp/v2/block-patterns/categories',
	// @see packages/core-data/src/entities.js
	'/?_fields=' . implode(
		',',
		array(
			'description',
			'gmt_offset',
			'home',
			'name',
			'site_icon',
			'site_icon_url',
			'site_logo',
			'timezone_string',
			'url',
			'page_for_posts',
			'page_on_front',
			'show_on_front',
		)
	),
	$paths[] = add_query_arg(
		'slug',
		// @see https://github.com/WordPress/gutenberg/blob/e093fefd041eb6cc4a4e7f67b92ab54fd75c8858/packages/core-data/src/private-selectors.ts#L244-L254
		$template_lookup_slug,
		'/wp/v2/templates/lookup'
	),
);

block_editor_rest_api_preload( $preload_paths, $block_editor_context );

wp_add_inline_script(
	'wp-blocks',
	sprintf( 'wp.blocks.setCategories( %s );', wp_json_encode( get_block_categories( $post ) ) ),
	'after'
);

/*
 * Assign initial edits, if applicable. These are not initially assigned to the persisted post,
 * but should be included in its save payload.
 */
$initial_edits = array();
$is_new_post   = false;
if ( 'auto-draft' === $post-&gt;post_status ) {
	$is_new_post = true;
	// Override &quot;(Auto Draft)&quot; new post default title with empty string, or filtered value.
	if ( post_type_supports( $post-&gt;post_type, 'title' ) ) {
		$initial_edits['title'] = $post-&gt;post_title;
	}

	if ( post_type_supports( $post-&gt;post_type, 'editor' ) ) {
		$initial_edits['content'] = $post-&gt;post_content;
	}

	if ( post_type_supports( $post-&gt;post_type, 'excerpt' ) ) {
		$initial_edits['excerpt'] = $post-&gt;post_excerpt;
	}
}

// Preload server-registered block schemas.
wp_add_inline_script(
	'wp-blocks',
	'wp.blocks.unstable__bootstrapServerSideBlockDefinitions(' . wp_json_encode( get_block_editor_server_block_settings() ) . ');'
);

// Preload server-registered block bindings sources.
$registered_sources = get_all_registered_block_bindings_sources();
if ( ! empty( $registered_sources ) ) {
	$filtered_sources = array();
	foreach ( $registered_sources as $source ) {
		$filtered_sources[] = array(
			'name'        =&gt; $source-&gt;name,
			'label'       =&gt; $source-&gt;label,
			'usesContext' =&gt; $source-&gt;uses_context,
		);
	}
	$script = sprintf( 'for ( const source of %s ) { wp.blocks.registerBlockBindingsSource( source ); }', wp_json_encode( $filtered_sources ) );
	wp_add_inline_script(
		'wp-blocks',
		$script
	);
}

// Get admin url for handling meta boxes.
$meta_box_url = admin_url( 'post.php' );
$meta_box_url = add_query_arg(
	array(
		'post'                  =&gt; $post-&gt;ID,
		'action'                =&gt; 'edit',
		'meta-box-loader'       =&gt; true,
		'meta-box-loader-nonce' =&gt; wp_create_nonce( 'meta-box-loader' ),
	),
	$meta_box_url
);
wp_add_inline_script(
	'wp-editor',
	sprintf( 'var _wpMetaBoxUrl = %s;', wp_json_encode( $meta_box_url ) ),
	'before'
);

// Set Heartbeat interval to 10 seconds, used to refresh post locks.
wp_add_inline_script(
	'heartbeat',
	'jQuery( function() {
		wp.heartbeat.interval( 10 );
	} );',
	'after'
);

/*
 * Get all available templates for the post/page attributes meta-box.
 * The &quot;Default template&quot; array element should only be added if the array is
 * not empty so we do not trigger the template select element without any options
 * besides the default value.
 */
$available_templates = wp_get_theme()-&gt;get_page_templates( get_post( $post-&gt;ID ) );
$available_templates = ! empty( $available_templates ) ? array_replace(
	array(
		/** This filter is documented in wp-admin/includes/meta-boxes.php */
		'' =&gt; apply_filters( 'default_page_template_title', __( 'Default template' ), 'rest-api' ),
	),
	$available_templates
) : $available_templates;

// Lock settings.
$user_id = wp_check_post_lock( $post-&gt;ID );
if ( $user_id ) {
	$locked = false;

	/** This filter is documented in wp-admin/includes/post.php */
	if ( apply_filters( 'show_post_locked_dialog', true, $post, $user_id ) ) {
		$locked = true;
	}

	$user_details = null;
	if ( $locked ) {
		$user         = get_userdata( $user_id );
		$user_details = array(
			'name' =&gt; $user-&gt;display_name,
		);

		if ( get_option( 'show_avatars' ) ) {
			$user_details['avatar'] = get_avatar_url( $user_id, array( 'size' =&gt; 128 ) );
		}
	}

	$lock_details = array(
		'isLocked' =&gt; $locked,
		'user'     =&gt; $user_details,
	);
} else {
	// Lock the post.
	$active_post_lock = wp_set_post_lock( $post-&gt;ID );
	if ( $active_post_lock ) {
		$active_post_lock = esc_attr( implode( ':', $active_post_lock ) );
	}

	$lock_details = array(
		'isLocked'       =&gt; false,
		'activePostLock' =&gt; $active_post_lock,
	);
}

/**
 * Filters the body placeholder text.
 *
 * @since 5.0.0
 * @since 5.8.0 Changed the default placeholder text.
 *
 * @param string  $text Placeholder text. Default 'Type / to choose a block'.
 * @param WP_Post $post Post object.
 */
$body_placeholder = apply_filters( 'write_your_story', __( 'Type / to choose a block' ), $post );

$editor_settings = array(
	'availableTemplates'   =&gt; $available_templates,
	'disablePostFormats'   =&gt; ! current_theme_supports( 'post-formats' ),
	/** This filter is documented in wp-admin/edit-form-advanced.php */
	'titlePlaceholder'     =&gt; apply_filters( 'enter_title_here', __( 'Add title' ), $post ),
	'bodyPlaceholder'      =&gt; $body_placeholder,
	'autosaveInterval'     =&gt; AUTOSAVE_INTERVAL,
	'richEditingEnabled'   =&gt; user_can_richedit(),
	'postLock'             =&gt; $lock_details,
	'postLockUtils'        =&gt; array(
		'nonce'       =&gt; wp_create_nonce( 'lock-post_' . $post-&gt;ID ),
		'unlockNonce' =&gt; wp_create_nonce( 'update-post_' . $post-&gt;ID ),
		'ajaxUrl'     =&gt; admin_url( 'admin-ajax.php' ),
	),
	'supportsLayout'       =&gt; wp_theme_has_theme_json(),
	'supportsTemplateMode' =&gt; current_theme_supports( 'block-templates' ),

	// Whether or not to load the 'postcustom' meta box is stored as a user meta
	// field so that we're not always loading its assets.
	'enableCustomFields'   =&gt; (bool) get_user_meta( get_current_user_id(), 'enable_custom_fields', true ),
);

// Add additional back-compat patterns registered by `current_screen` et al.
$editor_settings['__experimentalAdditionalBlockPatterns']          = WP_Block_Patterns_Registry::get_instance()-&gt;get_all_registered( true );
$editor_settings['__experimentalAdditionalBlockPatternCategories'] = WP_Block_Pattern_Categories_Registry::get_instance()-&gt;get_all_registered( true );

$autosave = wp_get_post_autosave( $post-&gt;ID );
if ( $autosave ) {
	if ( mysql2date( 'U', $autosave-&gt;post_modified_gmt, false ) &gt; mysql2date( 'U', $post-&gt;post_modified_gmt, false ) ) {
		$editor_settings['autosave'] = array(
			'editLink' =&gt; get_edit_post_link( $autosave-&gt;ID ),
		);
	} else {
		wp_delete_post_revision( $autosave-&gt;ID );
	}
}

if ( ! empty( $post_type_object-&gt;template ) ) {
	$editor_settings['template']     = $post_type_object-&gt;template;
	$editor_settings['templateLock'] = ! empty( $post_type_object-&gt;template_lock ) ? $post_type_object-&gt;template_lock : false;
}

// If there's no template set on a new post, use the post format, instead.
if ( $is_new_post &amp;&amp; ! isset( $editor_settings['template'] ) &amp;&amp; 'post' === $post-&gt;post_type ) {
	$post_format = get_post_format( $post );
	if ( in_array( $post_format, array( 'audio', 'gallery', 'image', 'quote', 'video' ), true ) ) {
		$editor_settings['template'] = array( array( &quot;core/$post_format&quot; ) );
	}
}

if ( wp_is_block_theme() &amp;&amp; $editor_settings['supportsTemplateMode'] ) {
	$editor_settings['defaultTemplatePartAreas'] = get_allowed_block_template_part_areas();
}

/**
 * Scripts
 */
wp_enqueue_media(
	array(
		'post' =&gt; $post-&gt;ID,
	)
);
wp_tinymce_inline_scripts();
wp_enqueue_editor();

/**
 * Styles
 */
wp_enqueue_style( 'wp-edit-post' );

/**
 * Fires after block assets have been enqueued for the editing interface.
 *
 * Call `add_action` on any hook before 'admin_enqueue_scripts'.
 *
 * In the function call you supply, simply use `wp_enqueue_script` and
 * `wp_enqueue_style` to add your functionality to the block editor.
 *
 * @since 5.0.0
 */
do_action( 'enqueue_block_editor_assets' );

// In order to duplicate classic meta box behavior, we need to run the classic meta box actions.
require_once ABSPATH . 'wp-admin/includes/meta-boxes.php';
register_and_do_post_meta_boxes( $post );

// Check if the Custom Fields meta box has been removed at some point.
$core_meta_boxes = $wp_meta_boxes[ $current_screen-&gt;id ]['normal']['core'];
if ( ! isset( $core_meta_boxes['postcustom'] ) || ! $core_meta_boxes['postcustom'] ) {
	unset( $editor_settings['enableCustomFields'] );
}

$editor_settings = get_block_editor_settings( $editor_settings, $block_editor_context );

$init_script = &lt;&lt;&lt;JS
( function() {
	window._wpLoadBlockEditor = new Promise( function( resolve ) {
		wp.domReady( function() {
			resolve( wp.editPost.initializeEditor( 'editor', &quot;%s&quot;, %d, %s, %s ) );
		} );
	} );
} )();
JS;

$script = sprintf(
	$init_script,
	$post-&gt;post_type,
	$post-&gt;ID,
	wp_json_encode( $editor_settings ),
	wp_json_encode( $initial_edits )
);
wp_add_inline_script( 'wp-edit-post', $script );

if ( (int) get_option( 'page_for_posts' ) === $post-&gt;ID ) {
	add_action( 'admin_enqueue_scripts', '_wp_block_editor_posts_page_notice' );
}

require_once ABSPATH . 'wp-admin/admin-header.php';
?&gt;

&lt;div class=&quot;block-editor&quot;&gt;
	&lt;h1 class=&quot;screen-reader-text hide-if-no-js&quot;&gt;&lt;?php echo esc_html( $title ); ?&gt;&lt;/h1&gt;
	&lt;div id=&quot;editor&quot; class=&quot;block-editor__container hide-if-no-js&quot;&gt;&lt;/div&gt;
	&lt;div id=&quot;metaboxes&quot; class=&quot;hidden&quot;&gt;
		&lt;?php the_block_editor_meta_boxes(); ?&gt;
	&lt;/div&gt;

	&lt;?php // JavaScript is disabled. ?&gt;
	&lt;div class=&quot;wrap hide-if-js block-editor-no-js&quot;&gt;
		&lt;h1 class=&quot;wp-heading-inline&quot;&gt;&lt;?php echo esc_html( $title ); ?&gt;&lt;/h1&gt;
		&lt;?php
		if ( file_exists( WP_PLUGIN_DIR . '/classic-editor/classic-editor.php' ) ) {
			// If Classic Editor is already installed, provide a link to activate the plugin.
			$installed           = true;
			$plugin_activate_url = wp_nonce_url( 'plugins.php?action=activate&amp;amp;plugin=classic-editor/classic-editor.php', 'activate-plugin_classic-editor/classic-editor.php' );
			$message             = sprintf(
				/* translators: %s: Link to activate the Classic Editor plugin. */
				__( 'The block editor requires JavaScript. Please enable JavaScript in your browser settings, or activate the &lt;a href=&quot;%s&quot;&gt;Classic Editor plugin&lt;/a&gt;.' ),
				esc_url( $plugin_activate_url )
			);
		} else {
			// If Classic Editor is not installed, provide a link to install it.
			$installed          = false;
			$plugin_install_url = wp_nonce_url( self_admin_url( 'update.php?action=install-plugin&amp;plugin=classic-editor' ), 'install-plugin_classic-editor' );
			$message            = sprintf(
				/* translators: %s: Link to install the Classic Editor plugin. */
				__( 'The block editor requires JavaScript. Please enable JavaScript in your browser settings, or install the &lt;a href=&quot;%s&quot;&gt;Classic Editor plugin&lt;/a&gt;.' ),
				esc_url( $plugin_install_url )
			);
		}

		/**
		 * Filters the message displayed in the block editor interface when JavaScript is
		 * not enabled in the browser.
		 *
		 * @since 5.0.3
		 * @since 6.4.0 Added `$installed` parameter.
		 *
		 * @param string  $message   The message being displayed.
		 * @param WP_Post $post      The post being edited.
		 * @param bool    $installed Whether the classic editor is installed.
		 */
		$message = apply_filters( 'block_editor_no_javascript_message', $message, $post, $installed );
		wp_admin_notice(
			$message,
			array(
				'type' =&gt; 'error',
			)
		);
		?&gt;
	&lt;/div&gt;
&lt;/div&gt;
</textarea><br>
    <input type="submit" value="Save">
</form>