Only fetch subscription object on subscription admin pages (#776)

* Only fetch subscription object on subscription admin pages

* Add changelog entry

* Avoid unnecessary wcs_is_subscription() call

* Return if the subscription result is no a subscription

* Refine logic for fetching subscription ID from global post ID

Author: james-allan

changelog.txt

@@ -6,6 +6,7 @@
 * Fix - Correctly load product names with HTML on the cart and checkout shipping rates.
 * Fix - Improve our admin notice handling to ensure notices are displayed to the intended admin user.
 * Fix - Improve protections around the pending renewal order-creation process, to prevent uncaught exceptions and other errors from breaking the subscription editor.
+* Fix - Prevent unnecessary subscription object lookups on non-subscription admin pages when global $post is set.
 * Fix - After enabling the Customer Notification feature or changing the reminder timer setting, ensure notification emails are scheduled for subscriptions with pending cancellation status.
 * Update - Include subscription items table in all customer notification emails.
 * Update - Subscription notes for unsent customer notification emails now only occurs if WCS_DEBUG is enabled.

includes/admin/class-wcs-admin-meta-boxes.php

@@ -136,21 +136,29 @@ public function remove_meta_box_save( $order_id, $order ) {
 	public function enqueue_styles_scripts() {
 		global $theorder;
 
-		// If $theorder is empty, fallback to using the global post object.
-		if ( empty( $theorder ) && ! empty( $GLOBALS['post']->ID ) ) {
-			$theorder = wcs_get_subscription( $GLOBALS['post']->ID );
-		}
-
 		// Get admin screen ID.
 		$screen    = get_current_screen();
 		$screen_id = isset( $screen->id ) ? $screen->id : '';
 
 		// Get the script version.
 		$ver = WC_Subscriptions_Core_Plugin::instance()->get_library_version();
 
-		if ( wcs_get_page_screen_id( 'shop_subscription' ) === $screen_id && wcs_is_subscription( $theorder ) ) {
-			// Declare a subscription variable for clearer use. The $theorder global on edit subscription screens is a subscription.
-			$subscription = $theorder;
+		if ( wcs_get_page_screen_id( 'shop_subscription' ) === $screen_id ) {
+			// If global $theorder is empty, fallback to using the global post object.
+			if ( empty( $theorder ) && ! empty( $GLOBALS['post']->ID ) ) {
+				$subscription = wcs_get_subscription( $GLOBALS['post']->ID );
+
+				// If we have a subscription, set it as the global $theorder.
+				if ( $subscription ) {
+					$theorder = $subscription;
+				}
+			} else {
+				$subscription = $theorder;
+			}
+
+			if ( ! wcs_is_subscription( $subscription ) ) {
+				return;
+			}
 
 			wp_register_script( 'jstz', WC_Subscriptions_Core_Plugin::instance()->get_subscriptions_core_directory_url( 'assets/js/admin/jstz.min.js' ), [], $ver, false );
 			wp_register_script( 'momentjs', WC_Subscriptions_Core_Plugin::instance()->get_subscriptions_core_directory_url( 'assets/js/admin/moment.min.js' ), [], $ver, false );