PROBLEM: Attribute's variation need to be activated manually after import SOLUTION: This patch actives attribute's variation when you import generic product in WooCommerce usign WP Ultimate CSV Importer Plugin, so you can import all product's variations using the same plugin

woocommerce-variation-attribute-active.php

<?php
/*
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  _\/\\\_______\/\\\_\/\\\_____\/\\\_____\///\\\/\\\/_____/\\\/////////\\\_\/\\\/\\\__\/\\\_      
   _\/\\\\\\\\\\\\\\__\/\\\\\\\\\\\/________\///\\\/______\/\\\_______\/\\\_\/\\\//\\\_\/\\\_     
    _\/\\\/////////\\\_\/\\\//////\\\__________\/\\\_______\/\\\\\\\\\\\\\\\_\/\\\\//\\\\/\\\_    
     _\/\\\_______\/\\\_\/\\\____\//\\\_________\/\\\_______\/\\\/////////\\\_\/\\\_\//\\\/\\\_   
      _\/\\\_______\/\\\_\/\\\_____\//\\\________\/\\\_______\/\\\_______\/\\\_\/\\\__\//\\\\\\_  
       _\/\\\\\\\\\\\\\/__\/\\\______\//\\\_______\/\\\_______\/\\\_______\/\\\_\/\\\___\//\\\\\_ 
        _\/////////////____\///________\///________\///________\///________\///__\///_____\/////__

Author: Alessandro Stranieri
Latest: 20130823
URL: http://www.bryan.it
License: GPLv3
License URI: http://www.gnu.org/licenses/gpl-3.0.html
*/

/**
 * REQUIRED: WooCommerce - excelling eCommerce - https://github.com/woothemes/woocommerce
 * REQUIRED: WP Ultimate CSV Importer Plugin - http://wordpress.org/plugins/wp-ultimate-csv-importer/
 * 
 * PROBLEM: Attribute's variation needs to be activated manually after import
 * SOLUTION: This patch activates attribute's variation when you import generic product in WooCommerce using WP Ultimate CSV Importer Plugin,
 * so you can import all product's variations using the same plugin.
 * Copy and paste the following code into your theme’s functions.php file.
 * 
 */

add_action('set_object_terms', 'woocommerce_variation_attribute_active', 10, 6);

function woocommerce_variation_attribute_active($object_id, $terms, $tt_ids, $taxonomy, $append, $old_tt_ids) {

    if (!$append) {

        if (substr($taxonomy, 0, 3) == 'pa_') {

            $attributes = array();

            $product_attributes = get_post_meta($object_id, '_product_attributes', false); 
            
            if (!empty($product_attributes[0])) {
                foreach ($product_attributes[0] as $prod_key => $value) {
                    $attributes[$prod_key] = $value; 
                }
            }
            
            $split_line = implode( ' | ', $terms );
            $attributes[ $taxonomy ] = array(
                'name'          => $taxonomy,
                'value'         => $split_line,
                'position'      => "",
                'is_visible'    => 1,
                'is_variation'  => 1,
                'is_taxonomy'   => 1
            );

            update_post_meta( $object_id, '_product_attributes', $attributes );

        }
    }

}

?>

hello, what i have to do to use this patch?
thank's
regards

Hi Stefano,
this patch is 8 years old, a bit outdated :)
I don't think it's still useful
thanks for writing