Set all variations out of stock if one variation is out of stock in WooCommerce

Question

We run a self-storage system with WooCommerce and we use WooCommerce Subscriptions plugin. Our storage units is a unique product with a Variable Subscription. Each variation has a different billing period (1 month, 3 months, 6 months and 12 months). I need the whole parent product, or at least all variations, to be out of stock if one variation is out of stock.

I didn't find any related setting and I didn't find how to make that possible yet.

Any help is appreciated.

Answer 1

The following will make all variations out of stock (for specific variable product(s)), when one variation is out of stock (also works with WooCommerce subscriptions):

add_filter('woocommerce_available_variation', 'set_all_variations_out_of_stock', 10, 3 );
function set_all_variations_out_of_stock( $data, $product, $variation ) {
    // Set the Id(s) of the related variable product(s) below in the array
    if( in_array( $product->get_id(), array(738) ) ){
        $out_of_stock = false; // initializing
        
        // Loop through children variations of the parent variable product
        foreach( $product->get_visible_children() as $_variation_id ) {
            if( $_variation_id != $data['variation_id'] ) {
                $_variation = wc_get_product($_variation_id);
                
                
                if( ! $_variation->is_in_stock() ) {
                    $out_of_stock = true; // Flag as out of stock
                    break;
                }
            }
        }
        if ( $out_of_stock ) {
            $data['availability_html'] = '<p class="stock out-of-stock">'. __('Out of stock', 'woocommerce') .'</p>';
            $data['is_in_stock'] = false;
        }
    }
    return $data;
}

Code goes in function.php file of your active child theme (active theme). Tested and works.

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Important note:

Stock can be managed on the parent variable product.

1. Enable stock management on the variable product (on Inventory tab) and set the stock there.
2. Disable stock management on each variation for this variable product.

You are done. The stock management is now handled on the variable product.