Only add the filters for WC_Customer_Data_Store_Custom_Table once

Instead of adding the hooks in the constructor (potentially causing a *ton* of hooked callbacks), register the customer data store hooks once.

includes/class-wc-customer-data-store-custom-table.php

@@ -12,17 +12,6 @@
  */
 class WC_Customer_Data_Store_Custom_Table extends WC_Customer_Data_Store {
 
-	/**
-	 * Register callbacks when the data store is first instantiated.
-	 */
-	public function __construct() {
-		add_filter( 'woocommerce_pre_customer_bought_product', __CLASS__ . '::pre_customer_bought_product', 10, 4 );
-
-		// Handle deleting a customer from the database.
-		add_action( 'deleted_user', __CLASS__ . '::reset_order_customer_id_on_deleted_user' );
-		remove_action( 'deleted_user', 'wc_reset_order_customer_id_on_deleted_user' );
-	}
-
 	/**
 	 * Gets the customers last order.
 	 *
@@ -139,6 +128,17 @@ public function get_total_spent( &$customer ) {
 		return $spent;
 	}
 
+	/**
+	 * Register callbacks when the data store is first instantiated.
+	 */
+	public static function add_hooks() {
+		add_filter( 'woocommerce_pre_customer_bought_product', __CLASS__ . '::pre_customer_bought_product', 10, 4 );
+
+		// Handle deleting a customer from the database.
+		add_action( 'deleted_user', __CLASS__ . '::reset_order_customer_id_on_deleted_user' );
+		remove_action( 'deleted_user', 'wc_reset_order_customer_id_on_deleted_user' );
+	}
+
 	/**
 	 * Short-circuit the wc_customer_bought_product() function.
 	 *

includes/class-woocommerce-custom-orders-table.php

@@ -42,6 +42,8 @@ public function setup() {
 		// When associating previous orders with a customer based on email, update the record.
 		add_action( 'woocommerce_update_new_customer_past_order', 'WooCommerce_Custom_Orders_Table_Filters::update_past_customer_order', 10, 2 );
 
+		WC_Customer_Data_Store_Custom_Table::add_hooks();
+
 		// Register the table within WooCommerce.
 		add_filter( 'woocommerce_install_get_tables', array( $this, 'register_table_name' ) );