• shaun

• October 18, 2017 at 6:52 pm

I was able to add ACF fields to woocommerce product variations using only a couple of actions and a filter.

// Render fields at the bottom of variations - does not account for field group order or placement.
add_action( 'woocommerce_product_after_variable_attributes', function( $loop, $variation_data, $variation ) {
    global $abcdefgh_i; // Custom global variable to monitor index
    $abcdefgh_i = $loop;
    // Add filter to update field name
    add_filter( 'acf/prepare_field', 'acf_prepare_field_update_field_name' );
    
    // Loop through all field groups
    $acf_field_groups = acf_get_field_groups();
    foreach( $acf_field_groups as $acf_field_group ) {
        foreach( $acf_field_group['location'] as $group_locations ) {
            foreach( $group_locations as $rule ) {
                // See if field Group has at least one post_type = Variations rule - does not validate other rules
                if( $rule['param'] == 'post_type' && $rule['operator'] == '==' && $rule['value'] == 'product_variation' ) {
                    // Render field Group
                    acf_render_fields( $variation->ID, acf_get_fields( $acf_field_group ) );
                    break 2;
                }
            }
        }
    }
    
    // Remove filter
    remove_filter( 'acf/prepare_field', 'acf_prepare_field_update_field_name' );
}, 10, 3 );

// Filter function to update field names
function  acf_prepare_field_update_field_name( $field ) {
    global $abcdefgh_i;
    $field['name'] = preg_replace( '/^acf\[/', "acf[$abcdefgh_i][", $field['name'] );
    return $field;
}
    
// Save variation data
add_action( 'woocommerce_save_product_variation', function( $variation_id, $i = -1 ) {
    // Update all fields for the current variation
    if ( ! empty( $_POST['acf'] ) && is_array( $_POST['acf'] ) && array_key_exists( $i, $_POST['acf'] ) && is_array( ( $fields = $_POST['acf'][ $i ] ) ) ) {
        foreach ( $fields as $key => $val ) {
            update_field( $key, $val, $variation_id );
        }
    }
}, 10, 2 );

Adding this code as is to your theme’s functions.php file should enable this functionality for all product variation field groups. The only drawback is that it doesn’t check for more complex rules, and the order and position of field groups are not taken into consideration.