woocommerce set_manage_stock not work in woocommerce_process_product_meta action

Question

I try to change the stock fileds programmatically , But it fail woth some fileds.

My question is: Why the set_manage_stock in the action not work , the set_stock_status work:

add_action('woocommerce_process_product_meta', function($post_id) {

    $product = wc_get_product($post_id);

    if( $_POST['_myvariable']==='yes'){

    $product->set_manage_stock(false);
    $product->set_stock_status('instock');
    $product->set_stock_quantity(99);

    }
    else{

        $product->set_manage_stock(true);
        $product->set_stock_status('instock');
        $product->set_stock_quantity(10);
    
    }

    $product->save();

}

Answer 1

Tested OK with WooCommerce 6.3. This will create a product automatically when you add a new product from the admin.

/**
 * Save meta box data.
 *
 * @param int     $post_id WP post id.
 * @param WP_Post $post Post object.
 */
function action_woocommerce_process_product_meta($post_id, $post) {
    // make action magic happen here... 


    $product = new WC_Product_Simple();
    $product->set_name('Sample product ');
    $product->set_status('publish');
    $product->set_catalog_visibility('visible');
    $product->set_price(19.99);
    $product->set_regular_price(19.99);
    $product->set_sold_individually(true);
    $product->set_manage_stock(true);
    $product->set_stock_status('instock');
    $product->set_stock_quantity(10);
    $product->save();
}

// add the action 
add_action('woocommerce_process_product_meta', 'action_woocommerce_process_product_meta', 10, 2);