mikejolley · September 13, 2021 20:45 · Jun 1, 2016 · May 31, 2016
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -3,7 +3,7 @@
 /**
  * Code goes in theme functions.php.
  * Product must have upsells, and this works with simple products only.
- * Example link: yoursite.com/add-upsells-to-cart=X, X being your product ID.
+ * Example link: yoursite.com?add-upsells-to-cart=X, X being your product ID.
  */
 add_action( 'wp_loaded', 'bulk_upsell_add_to_cart_action', 20 );
 

diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1,31 @@
+<?php // Do not include this if already open!
+
+/**
+ * Code goes in theme functions.php.
+ * Product must have upsells, and this works with simple products only.
+ * Example link: yoursite.com/add-upsells-to-cart=X, X being your product ID.
+ */
+add_action( 'wp_loaded', 'bulk_upsell_add_to_cart_action', 20 );
+
+function bulk_upsell_add_to_cart_action() {
+	if ( ! empty( $_GET['add-upsells-to-cart'] ) ) {
+		$product_id = absint( $_GET['add-upsells-to-cart'] );
+		$product    = wc_get_product( $product_id );
+
+		if ( $product ) {
+			$upsell_ids = $product->get_upsells();
+
+			if ( $upsell_ids ) {
+				$count = 0;
+
+				foreach ( $upsell_ids as $upsell_id ) {
+					if ( WC()->cart->add_to_cart( $upsell_id ) ) {
+						$count ++;
+					}
+				}
+
+				wc_add_notice( sprintf( _n( 'Added %d item to the cart', 'Added %d items to the cart', $count ), $count ) );
+			}
+		}
+	}
+}