Avoid loading Gutenberg assets in other admin pages

gutenberg.php

@@ -79,6 +79,35 @@ function gutenberg_menu() {
 }
 add_action( 'admin_menu', 'gutenberg_menu' );
 
+/**
+ * Checks whether we're currently loading a Gutenberg page
+ *
+ * @return boolean Whether Gutenberg is being loaded.
+ *
+ * @since 3.1.0
+ */
+function is_gutenberg_page() {
+ global $post;
+
+ if ( ! is_admin() ) {
+ return false;
+ }
+
+ if ( get_current_screen()->base !== 'post' ) {
+ return false;
+ }
+
+ if ( isset( $_GET['classic-editor'] ) ) {
+ return false;
+ }
+
+ if ( ! gutenberg_can_edit_post( $post ) ) {
+ return false;
+ }
+
+ return true;
+}
+
 /**
  * Display a version notice and deactivate the Gutenberg plugin.
  *
@@ -150,11 +179,7 @@ function gutenberg_init( $return, $post ) {
  return $return;
  }
 
- if ( isset( $_GET['classic-editor'] ) ) {
- return false;
- }
-
- if ( ! gutenberg_can_edit_post( $post ) ) {
+ if ( ! is_gutenberg_page() ) {
  return false;
  }
 

lib/client-assets.php

@@ -845,6 +845,10 @@ function gutenberg_prepare_blocks_for_js() {
  * @since 0.4.0
  */
 function gutenberg_common_scripts_and_styles() {
+ if ( ! is_gutenberg_page() && is_admin() ) {
+ return;
+ }
+
  // Enqueue basic styles built out of Gutenberg through `npm build`.
  wp_enqueue_style( 'wp-core-blocks' );
 
@@ -1160,21 +1164,7 @@ function gutenberg_editor_scripts_and_styles( $hook ) {
  * Remove this in Gutenberg 3.1
  */
 function polyfill_blocks_module_in_scripts() {
- global $post;
-
- if ( ! is_admin() ) {
- return;
- }
-
- if ( get_current_screen()->base !== 'post' ) {
- return;
- }
-
- if ( isset( $_GET['classic-editor'] ) ) {
- return;
- }
-
- if ( ! gutenberg_can_edit_post( $post ) ) {
+ if ( ! is_gutenberg_page() ) {
  return;
  }