From 72c295490f18c208e2699f4453c635e5b9fe6726 Mon Sep 17 00:00:00 2001
From: Laura Lebovic <laura.lebovic@gmail.com>
Date: Wed, 16 Apr 2025 16:13:24 +0200
Subject: [PATCH] Add external ID retrieval to Event class and adjust action
 priorities

---
 facebook-commerce-events-tracker.php |  6 +++---
 includes/Events/Event.php            | 24 ++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/facebook-commerce-events-tracker.php b/facebook-commerce-events-tracker.php
index afc1d55b9..ecb9c224d 100644
--- a/facebook-commerce-events-tracker.php
+++ b/facebook-commerce-events-tracker.php
@@ -98,12 +98,12 @@ private function is_pixel_enabled() {
 		private function add_hooks() {
 
 			// inject Pixel
-			add_action( 'wp_head', array( $this, 'inject_base_pixel' ) );
+			add_action( 'wp_head', array( $this, 'inject_base_pixel' ), 1 );
 			add_action( 'wp_footer', array( $this, 'inject_base_pixel_noscript' ) );
 
 			// ViewContent for individual products
-			add_action( 'woocommerce_after_single_product', array( $this, 'inject_view_content_event' ) );
-			add_action( 'woocommerce_after_single_product', array( $this, 'maybe_inject_search_event' ) );
+			add_action( 'woocommerce_after_single_product', array( $this, 'inject_view_content_event' ), 20 );
+			add_action( 'woocommerce_after_single_product', array( $this, 'maybe_inject_search_event' ), 20 );
 
 			// ViewCategory events
 			add_action( 'woocommerce_after_shop_loop', array( $this, 'inject_view_category_event' ) );
diff --git a/includes/Events/Event.php b/includes/Events/Event.php
index 26c2388f6..6efb17665 100644
--- a/includes/Events/Event.php
+++ b/includes/Events/Event.php
@@ -116,6 +116,7 @@ protected function prepare_user_data( $data ) {
 				'client_user_agent' => $this->get_client_user_agent(),
 				'click_id'          => $this->get_click_id(),
 				'browser_id'        => $this->get_browser_id(),
+				'external_id'       => $this->get_external_id(),
 			)
 		);
 		// Country key is not the same in pixel and CAPI events, see:
@@ -277,6 +278,29 @@ protected function get_browser_id() {
 		return ! empty( $_COOKIE['_fbp'] ) ? wc_clean( wp_unslash( $_COOKIE['_fbp'] ) ) : '';
 	}
 
+	/**
+	 * Retrieves the external ID based on the session's customer ID.
+	 *
+	 * @since 2.0.0
+	 *
+	 * @return string The external ID if available, or an empty string otherwise.
+	 */
+	protected function get_external_id()
+	{
+		// Ensure the WooCommerce session exists and has the get_customer_id method
+		if (isset(WC()->session) && method_exists(WC()->session, 'get_customer_unique_id')) {
+			$customer_id = WC()->session->get_customer_unique_id();
+
+			// Return the customer ID as a string if it exists
+			if (! empty($customer_id)) {
+				return strval($customer_id);
+			}
+		}
+
+		// Return an empty string if no customer ID is available
+		return '';
+	}
+
 
 	/**
 	 * Gets the data.