php - Change product category once the order status get completed -

i want apply new category product once order status "completed" in woocommerce. let's product in (category a) , want apply (category b) on order status "completed".

is there way this?

i found couple of tutorials don't know how combine them:

https://wordpress.org/support/topic/automatically-add-posts-to-a-category-conditionally

https://wordpress.org/support/topic/woocommerce-on-order-complete-insert-quantity-data-into-custom-database-table

how can achieve this?

thanks!

updated (compatibility woocommerce 3+)

as want change woocommerce category product, should use wp_set_object_terms() native wordpress function accept either category id or slug with 'product_cat' taxonomy parameter , not 'category'.

the woocommerce_order_status_completed hook classically used fire callback function when order change status completed.

this code:

add_action('woocommerce_order_status_completed', 'add_category_to_order_items_on_competed_status' 10, 1);  function add_category_to_order_items_on_competed_status( $order_id ) {      // set category id or slug     $your_category = 'my-category-slug'; // or $your_category = 123;       $order = wc_get_order( $order_id );      foreach ( $order->get_items() $item_id => $product_item ) {         // compatibility wc +3         if ( version_compare( wc_version, '3.0', '<' ) )              $product_id = $product_item['product_id'];         else             $product_id = $product_item->get_product_id();          wp_set_object_terms( $product_id, $your_category, 'product_cat' );     } } 

or can use woocommerce_order_status_changed hook conditional function filter order "completed" status:

add_action('woocommerce_order_status_changed', 'add_category_to_order_items_on_competed_status' 10, 1);  function add_category_to_order_items_on_competed_status( $order_id ) {      // set category id or slug     $your_category = 'my-category-slug'; // or $your_category = 123;       $order = wc_get_order( $order_id );     $order_status =  $order->post->post_status;      if ( $order->has_status( 'completed' ) ) {         foreach ( $order->get_items() $item_id => $product_item ) {             // compatibility wc +3             if ( version_compare( wc_version, '3.0', '<' ) )                  $product_id = $product_item['product_id'];             else                 $product_id = $product_item->get_product_id();              wp_set_object_terms( $product_id, $your_category, 'product_cat' );         }     } } 

this code goes on function.php file of active child theme or theme.

this code tested , functional.