Add a new product from a custom product type programmatically in WooCommerce 4

Question

I want to create a product from frontend directly to a grouped product in woocommerce. Right now it is creating a product in "Simple Product".

Screenshot:

Current code:

$auction_image =  $_POST['auction_image_url']?: '';
$auction_title =  $_POST['auction_title'] ?: '';
$auction_category = $_POST['auction_category'] ?: 'auction';
 
$author_id = $_POST['author_id'] ?: '';

$auction = array(
        'post_author' => $author_id,
        'post_content' => 'Description',
        'post_status' => "publish",
        'post_title' => $auction_title,
        'post_parent' => '',
        'post_type' => "product",
    );

//Create post
$auction_id = wp_insert_post($auction, $wp_error);
if ($auction_id) {
    save_featured_image($auction_image, $auction_id);
    wp_set_object_terms($auction_id, $auction_category, 'product_cat');
    update_post_meta($auction_id, '_author_id', $author_id);
    wp_send_json_success(array('auction_id' => $auction_id,'message' => 'Auction Added Successfully!!'), 200);
} else {
    wp_send_json_error($product_id->get_error_message());
}

Answer 1

1). Instead of using the WordPress old way, since WooCommerce 3, Use WC_Order methods instead.

Important notes:

• Product Image: Normally the image is set from an attachment id, but not from an URL. Also save_featured_image() is not a WordPress function.
• Product name (or title): Is mandatory.
• There are a lot of mistakes and errors in your provided code.

Product types and custom product types

• In the code below you will have to define the product type.
• Custom product type: It will be necessary to define also the Class name as defined for the custom product type source code Class.

For example for a "grouped" product type:

$auction_title    = isset($_POST['auction_title']) ? sanitize_text_field($_POST['auction_title']) : '';
$auction_category = isset($_POST['auction_category']) ? esc_attr($_POST['auction_category']) : 'auction';

$product_type = 'grouped'; // <== Here define your product type slug
$class_name   = WC_Product_Factory::get_classname_from_product_type($product_type); // Get the product Class name

// If the product class exist for the defined product type
if( ! empty($class_name) && class_exists( $class_name ) ) {
    $product = new $class_name(); // Get an empty instance of a grouped product Object
}
// For a custom product class
else {
    $class_name = 'WC_Product_custom'; // <== Here define the Class name of your custom product type

    if( class_exists( $class_name ) ) {
        $product = new $class_name(); // Get an empty instance of a custom class product Object
    } else {
        wp_send_json_error( array( 'message' =>__('Wrong product class') ), 409 );
        return; // or exit;
    }
}

$product->set_name($auction_title);
$product->set_description('Description');
$product->set_short_description('Short_description');
$product->set_status('publish');

// $product-> set_image_id( $image_id ); // ???

$category_term = get_term_by( 'slug', $auction_category, 'product_cat' ); // Get the term from its slug
if( is_a($category_term, 'WP_Term') ) {
    $product->set_category_ids( array($category_term->term_id) );
}

$product_id = $product->save(); // Save product to database

if ( $product_id ) { 
    // Set the post author
    if( isset($_POST['author_id']) ) {
        wp_update_post('ID' => $product_id, 'post_author' => esc_attr($_POST['author_id']) );
    }

    wp_send_json_success(array('auction_id' => $product_id,'message' => __('Auction Added Successfully!!') ), 200);
} else {
    wp_send_json_error( array( 'auction_id' => $product_id, 'message' =>__('Auction failed :(') ), 400 );
}

This code should better works.

---

2). Or you can still use the Wordpress Old Way combined:

$auction_data = array(
    'post_author'  => isset($_POST['author_id']) ? esc_attr($_POST['author_id']) : '',
    'post_content' => 'Description',
    'post_status'  => "publish",
    'post_title'   => isset($_POST['auction_title']) ? sanitize_text_field($_POST['auction_title']) : __('Empty title'),
    'post_parent'  => '',
    'post_type'    => "product",
);

$auction_id = wp_insert_post($auction_data, $wp_error);

if ( $auction_id ) {
    $auction_category = isset($_POST['auction_category']) ? esc_attr($_POST['auction_category']) : 'auction';
    wp_set_object_terms( $auction_id, $auction_category, 'product_cat' );
    
    if( isset($_POST['auction_image_url']) && function_exists('save_featured_image') ) {
        save_featured_image($auction_image, ecs_attr($_POST['auction_image_url']));
    }

    update_post_meta( $auction_id, '_author_id', $author_id );
    
    $product_type = 'grouped'; // <== Here define your product type slug
    $class_name   = WC_Product_Factory::get_product_classname( $product_id, $new_product_type );
    
    // If the product class exist for the defined product type
    if( ! empty($class_name) && class_exists( $class_name ) ) {
        $product = new $class_name($auction_id); // Get an empty instance of a grouped product Object
    }
    // For a custom product class (you may have to define the custom class name)
    else {
        $class_name = 'WC_Product_custom'; // <== Here define the Class name of your custom product type
    
        if( class_exists( $class_name ) ) {
            $product = new $class_name($auction_id); // Get an empty instance of a custom class product Object
        } else {
            wp_send_json_error( array( 'message' =>__('Wrong product class') ), 409 );
            return; // or exit;
        }
    }

    $auction_id = $product->save(); // Save to database
    
    wp_send_json_success( array('auction_id' => $auction_id, 'message' => __('Auction Added Successfully!!') ), 200 );
} else {
    wp_send_json_error( array('message' => __('Auction Failed') 400 );
}

This should also work.

---

Related:

• Create programmatically a product using CRUD methods in Woocommerce 3
• Change the product type of an existing product in WooCommerce 3+
• Source code for WC_Product Class (methods) and WC_Product_Grouped Class (methods)