Add woocommerce product programmaticaly (with attributes)

woo_add_product_programmatically.php

<?php
/**
  * SOURCE: https://stackoverflow.com/questions/52937409/create-programmatically-a-product-using-crud-methods-in-woocommerce-3
  */

/* THE CODE FUNCTION */

// Custom function for product creation (For Woocommerce 3+ only)
function create_product( $args ){
    global $woocommerce;

    if( ! function_exists('wc_get_product_object_type') && ! function_exists('wc_prepare_product_attributes') )
        return false;

    // Get an empty instance of the product object (defining it's type)
    $product = wc_get_product_object_type( $args['type'] );
    if( ! $product )
        return false;

    // Product name (Title) and slug
    $product->set_name( $args['name'] ); // Name (title).
    if( isset( $args['slug'] ) )
        $product->set_name( $args['slug'] );

    // Description and short description:
    $product->set_description( $args['description'] );
    $product->set_short_description( $args['short_description'] );

    // Status ('publish', 'pending', 'draft' or 'trash')
    $product->set_status( isset($args['status']) ? $args['status'] : 'publish' );

    // Visibility ('hidden', 'visible', 'search' or 'catalog')
    $product->set_catalog_visibility( isset($args['visibility']) ? $args['visibility'] : 'visible' );

    // Featured (boolean)
    $product->set_featured(  isset($args['featured']) ? $args['featured'] : false );

    // Virtual (boolean)
    $product->set_virtual( isset($args['virtual']) ? $args['virtual'] : false );

    // Prices
    $product->set_regular_price( $args['regular_price'] );
    $product->set_sale_price( isset( $args['sale_price'] ) ? $args['sale_price'] : '' );
    $product->set_price( isset( $args['sale_price'] ) ? $args['sale_price'] :  $args['regular_price'] );
    if( isset( $args['sale_price'] ) ){
        $product->set_date_on_sale_from( isset( $args['sale_from'] ) ? $args['sale_from'] : '' );
        $product->set_date_on_sale_to( isset( $args['sale_to'] ) ? $args['sale_to'] : '' );
    }

    // Downloadable (boolean)
    $product->set_downloadable(  isset($args['downloadable']) ? $args['downloadable'] : false );
    if( isset($args['downloadable']) && $args['downloadable'] ) {
        $product->set_downloads(  isset($args['downloads']) ? $args['downloads'] : array() );
        $product->set_download_limit(  isset($args['download_limit']) ? $args['download_limit'] : '-1' );
        $product->set_download_expiry(  isset($args['download_expiry']) ? $args['download_expiry'] : '-1' );
    }

    // Taxes
    if ( get_option( 'woocommerce_calc_taxes' ) === 'yes' ) {
        $product->set_tax_status(  isset($args['tax_status']) ? $args['tax_status'] : 'taxable' );
        $product->set_tax_class(  isset($args['tax_class']) ? $args['tax_class'] : '' );
    }

    // SKU and Stock (Not a virtual product)
    if( isset($args['virtual']) && ! $args['virtual'] ) {
        $product->set_sku( isset( $args['sku'] ) ? $args['sku'] : '' );
        $product->set_manage_stock( isset( $args['manage_stock'] ) ? $args['manage_stock'] : false );
        $product->set_stock_status( isset( $args['stock_status'] ) ? $args['stock_status'] : 'instock' );
        if( isset( $args['manage_stock'] ) && $args['manage_stock'] ) {
            $product->set_stock_status( $args['stock_qty'] );
            $product->set_backorders( isset( $args['backorders'] ) ? $args['backorders'] : 'no' ); // 'yes', 'no' or 'notify'
        }
    }

    // Sold Individually
    $product->set_sold_individually( isset( $args['sold_individually'] ) ? $args['sold_individually'] : false );

    // Weight, dimensions and shipping class
    $product->set_weight( isset( $args['weight'] ) ? $args['weight'] : '' );
    $product->set_length( isset( $args['length'] ) ? $args['length'] : '' );
    $product->set_width( isset(  $args['width'] ) ?  $args['width']  : '' );
    $product->set_height( isset( $args['height'] ) ? $args['height'] : '' );
    if( isset( $args['shipping_class_id'] ) )
        $product->set_shipping_class_id( $args['shipping_class_id'] );

    // Upsell and Cross sell (IDs)
    $product->set_upsell_ids( isset( $args['upsells'] ) ? $args['upsells'] : '' );
    $product->set_cross_sell_ids( isset( $args['cross_sells'] ) ? $args['upsells'] : '' );

    // Attributes et default attributes
    if( isset( $args['attributes'] ) )
        $product->set_attributes( wc_prepare_product_attributes($args['attributes']) );
    if( isset( $args['default_attributes'] ) )
        $product->set_default_attributes( $args['default_attributes'] ); // Needs a special formatting

    // Reviews, purchase note and menu order
    $product->set_reviews_allowed( isset( $args['reviews'] ) ? $args['reviews'] : false );
    $product->set_purchase_note( isset( $args['note'] ) ? $args['note'] : '' );
    if( isset( $args['menu_order'] ) )
        $product->set_menu_order( $args['menu_order'] );

    // Product categories and Tags
    if( isset( $args['category_ids'] ) )
        $product->set_category_ids( 'category_ids' );
    if( isset( $args['tag_ids'] ) )
        $product->set_tag_ids( $args['tag_ids'] );


    // Images and Gallery
    $product->set_image_id( isset( $args['image_id'] ) ? $args['image_id'] : "" );
    $product->set_gallery_image_ids( isset( $args['gallery_ids'] ) ? $args['gallery_ids'] : array() );

    ## --- SAVE PRODUCT --- ##
    $product_id = $product->save();

    return $product_id;
}

// Utility function that returns the correct product object instance
function wc_get_product_object_type( $type )
    // Get an instance of the WC_Product object (depending on his type)
    if( isset($args['type']) && $args['type'] === 'variable' ){
        $product = new WC_Product_Variable();
    } elseif( isset($args['type']) && $args['type'] === 'grouped' ){
        $product = new WC_Product_Grouped();
    } elseif( isset($args['type']) && $args['type'] === 'external' ){
        $product = new WC_Product_External();
    } else {
        $product = new WC_Product_Simple(); // "simple" By default
    } 
    
    if( ! is_a( $product, 'WC_Product' ) )
        return false;
    else
        return $product;
}

// Utility function that prepare product attributes before saving
function wc_prepare_product_attributes( $attributes ){
    global $woocommerce;

    $data = array();
    $position = 0;

    foreach( $attributes as $taxonomy => $values ){
        if( ! taxonomy_exists( $taxonomy ) )
            continue;

        // Get an instance of the WC_Product_Attribute Object
        $attribute = new WC_Product_Attribute();

        $term_ids = array();

        // Loop through the term names
        foreach( $values['term_names'] as $term_name ){
            if( term_exists( $term_name, $taxonomy ) )
                // Get and set the term ID in the array from the term name
                $term_ids[] = get_term_by( 'name', $term_name, $taxonomy )->term_id;
            else
                continue;
        }

        $taxonomy_id = wc_attribute_taxonomy_id_by_name( $taxonomy ); // Get taxonomy ID

        $attribute->set_id( $taxonomy_id );
        $attribute->set_name( $taxonomy );
        $attribute->set_options( $term_ids );
        $attribute->set_position( $position );
        $attribute->set_visible( $values['is_visible'] );
        $attribute->set_variation( $values['for_variation'] );

        $data[$taxonomy] = $attribute; // Set in an array

        $position++; // Increase position
    }
    return $data;
}

/* USAGE: - Example for a simple product creation with 2 product attributes "Color" and "Size": */

$product_id = create_product( array(
    'type'               => '', // Simple product by default
    'name'               => __("The product title", "woocommerce"),
    'description'        => __("The product description…", "woocommerce"),
    'short_description'  => __("The product short description…", "woocommerce"),
    // 'sku'                => '',
    'regular_price'      => '5.00', // product price
    // 'sale_price'         => '',
    'reviews_allowed'    => true,
    'attributes'         => array(
        // Taxonomy and term name values
        'pa_color' => array(
            'term_names' => array('Red', 'Blue'),
            'is_visible' => true,
            'for_variation' => false,
        ),
        'pa_size' =>  array(
            'term_names' => array('X Large'),
            'is_visible' => true,
            'for_variation' => false,
        ),
    ),
) );  

// Displaying the created product ID
echo $product_id;