Check stock-status of configurable product (display OutOfStock when all child products are out of stock)

Question

I got the following code to check the status of a configurable product. Basically, the stock status of all child products has to be checked, and as all child products are out of stock, the command would display 'OutOfStock', but the commands not still achieving what I want, since it displays InStock when all child products are out of stock. What could be going wrong?

 <?php
 $_product = Mage::registry('current_product');
 $stockItem = $_product->getStockItem();
 $isInStock = $stockItem->getIsInStock();
 $stockString = ($isInStock ? "In" : "OutOf")
 ;?>

 <script type="application/ld+json">
 {    
 "offers": {
         "availability": "<?php echo $stockString ."Stock"; ?>",
     }
 }
 </script>

`

Answer 1

The solution was as follows:

$_product = Mage::registry('current_product');
$isInStock = $_product->isSaleable();
$stockString = ($isInStock ? "In" : "OutOf");

And then the snippet would look like:

"availability": "<?php echo "https://schema.org/". $stockString ."Stock"; ?>",