Display sold out on WooCommerce variable product when all variations are out of stock

You can create a custom conditional function to check if all variations of a variable product are "out of stock" as follows:

function is_variable_product_out_of_stock( $product ) {    $children_count = 0; // initializing    $variation_ids  = $product->get_visible_children();            // Loop through children variations of the parent variable product    foreach( $variation_ids as $variation_id ) {{        $variation = wc_get_product($_variation_id); // Get the product variation Object                    if( ! $variation->is_in_stock() ) {            $children_count++; // count out of stock children        }    }    // Compare counts and return a boolean    return count($variation_ids) == $children_count ? true : false;}

Then you will use it in your revisited hooked function below:

add_action( 'woocommerce_before_shop_loop_item_title', 'display_products_loop_out_of_stock' ); function display_products_loop_out_of_stock() {    global $product;    if ( ( ! $product->is_type('variable') && ! $product->is_in_stock()  )     || ( $product->is_type('variable') && is_variable_product_out_of_stock( $product ) ) ) {        echo '<span class="soldout">Sold Out</span>';    }} 

Code goes in functions.php file of the active child theme (or active theme). It should works.

I made a lighter version of @LoicTheAztec 's function that will stop looping as soon as it finds a variable that is in stock:

function is_variable_product_out_of_stock($product) {    $variation_ids = $product->get_visible_children();    foreach($variation_ids as $variation_id) {        $variation = wc_get_product($variation_id);        if ($variation->is_in_stock())            return false;    }    return true;}

Also with no fatal error because he made two critical typos in his function.

You can the do something custom like he did:

add_action('woocommerce_before_shop_loop_item_title', 'display_products_loop_out_of_stock');function display_products_loop_out_of_stock() {    global $product;    if ((!$product->is_type('variable') and !$product->is_in_stock()) or ($product->is_type('variable') and is_variable_product_out_of_stock($product)))        echo '<span class="soldout">Sold Out</span>';}