How to display Sale label on configurable product

Create a <div> with your SALE label on the product list page where you want to display the SALE label. For e.g.

<div class="sale_label" style="display: none;">//your sale label</div> 

Now on the same file check if the current product is configurable product than check if its child products have a special price or not.

$configProduct = $objectManager->create('Magento\Catalog\Model\Product')->load($product_id); $_children = $configProduct->getTypeInstance()->getUsedProducts($configProduct); $salePrice = array(); foreach ($_children as $child){ $salePrice[] = $child->getSpecialPrice(); } if($salePrice != ''){ ?> <script> require(['jquery', 'jquery/ui'], function($){ jQuery(document).ready( function() { jQuery("sale_label").show(); }); }); </script> <?php } ?> 

You can use it without Object Manager.

Our solution for a customer was, to create a new attribute is_on_sale which is updated each time a configurable or it's simples are changed.

Then we simply use that attribute to display a sale label and also can filter by this attribute.

Not a super sophisticated solution, but it works.

Other solutions have the problem that you either need to load all simples in the product-list-loop which has a big performance impact or mess around with the indexers.