Disable layout styles in classic themes

Author: youknowriad

src/wp-includes/class-wp-theme-json.php

@@ -1333,7 +1333,6 @@ public function get_settings() {
 	 *                          - `variables`: only the CSS Custom Properties for presets & custom ones.
 	 *                          - `styles`: only the styles section in theme.json.
 	 *                          - `presets`: only the classes for the presets.
-	 *                          - `base-layout-styles`: only the base layout styles.
 	 *                          - `custom-css`: only the custom CSS.
 	 * @param string[] $origins A list of origins to include. By default it includes VALID_ORIGINS.
 	 * @param array    $options {
@@ -1400,42 +1399,6 @@ public function get_stylesheet( $types = array( 'variables', 'styles', 'presets'
 				$stylesheet .= $this->get_root_layout_rules( $style_nodes[ $root_style_key ]['selector'], $style_nodes[ $root_style_key ] );
 			}
 			$stylesheet .= $this->get_block_classes( $style_nodes );
-		} elseif ( in_array( 'base-layout-styles', $types, true ) ) {
-			$root_selector          = static::ROOT_BLOCK_SELECTOR;
-			$columns_selector       = '.wp-block-columns';
-			$post_template_selector = '.wp-block-post-template';
-			if ( ! empty( $options['scope'] ) ) {
-				$root_selector          = static::scope_selector( $options['scope'], $root_selector );
-				$columns_selector       = static::scope_selector( $options['scope'], $columns_selector );
-				$post_template_selector = static::scope_selector( $options['scope'], $post_template_selector );
-			}
-			if ( ! empty( $options['root_selector'] ) ) {
-				$root_selector = $options['root_selector'];
-			}
-			/*
-			 * Base layout styles are provided as part of `styles`, so only output separately if explicitly requested.
-			 * For backwards compatibility, the Columns block is explicitly included, to support a different default gap value.
-			 */
-			$base_styles_nodes = array(
-				array(
-					'path'     => array( 'styles' ),
-					'selector' => $root_selector,
-				),
-				array(
-					'path'     => array( 'styles', 'blocks', 'core/columns' ),
-					'selector' => $columns_selector,
-					'name'     => 'core/columns',
-				),
-				array(
-					'path'     => array( 'styles', 'blocks', 'core/post-template' ),
-					'selector' => $post_template_selector,
-					'name'     => 'core/post-template',
-				),
-			);
-
-			foreach ( $base_styles_nodes as $base_style_node ) {
-				$stylesheet .= $this->get_layout_styles( $base_style_node, $types );
-			}
 		}
 
 		if ( in_array( 'presets', $types, true ) ) {
@@ -1783,8 +1746,9 @@ protected function get_layout_styles( $block_metadata, $types = array() ) {
 					foreach ( $base_style_rules as $base_style_rule ) {
 						$declarations = array();
 
-						// Skip outputting base styles for flow and constrained layout types if theme doesn't support theme.json. The 'base-layout-styles' type flags this.
-						if ( in_array( 'base-layout-styles', $types, true ) && ( 'default' === $layout_definition['name'] || 'constrained' === $layout_definition['name'] ) ) {
+						// Skip outputting base styles for flow and constrained layout types for classic themes without theme.json.
+						// These themes don't use .wp-site-blocks wrapper, so these layout-specific alignment styles aren't needed.
+						if ( ! wp_is_block_theme() && ! wp_theme_has_theme_json() && ( 'default' === $layout_definition['name'] || 'constrained' === $layout_definition['name'] ) ) {
 							continue;
 						}
 
@@ -3107,9 +3071,13 @@ public function get_root_layout_rules( $selector, $block_metadata ) {
 			$css .= '.has-global-padding :where(:not(.alignfull.is-layout-flow) > .has-global-padding:not(.wp-block-block, .alignfull)) > .alignfull { margin-left: 0; margin-right: 0; }';
 		}
 
-		$css .= '.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }';
-		$css .= '.wp-site-blocks > .alignright { float: right; margin-left: 2em; }';
-		$css .= '.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }';
+		// Skip outputting alignment styles for classic themes without theme.json.
+		// These styles target .wp-site-blocks which is only used by block themes.
+		if ( wp_is_block_theme() || wp_theme_has_theme_json() ) {
+			$css .= '.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }';
+			$css .= '.wp-site-blocks > .alignright { float: right; margin-left: 2em; }';
+			$css .= '.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }';
+		}
 
 		// Block gap styles will be output unless explicitly set to `null`. See static::PROTECTED_PROPERTIES.
 		if ( isset( $this->theme_json['settings']['spacing']['blockGap'] ) ) {

src/wp-includes/global-styles-and-settings.php

@@ -135,14 +135,11 @@ function wp_get_global_styles( $path = array(), $context = array() ) {
  * Returns the stylesheet resulting of merging core, theme, and user data.
  *
  * @since 5.9.0
- * @since 6.1.0 Added 'base-layout-styles' support.
  * @since 6.6.0 Resolves relative paths in theme.json styles to theme absolute paths.
  *
  * @param array $types Optional. Types of styles to load.
  *                     See {@see 'WP_Theme_JSON::get_stylesheet'} for all valid types.
- *                     If empty, it'll load the following:
- *                     - for themes without theme.json: 'variables', 'presets', 'base-layout-styles'.
- *                     - for themes with theme.json: 'variables', 'presets', 'styles'.
+ *                     If empty, will load: 'variables', 'presets', 'styles'.
  * @return string Stylesheet.
  */
 function wp_get_global_stylesheet( $types = array() ) {