RpcApi.php

<?php

function validateProducts($products) {

    // Check to make sure that our valid fields are in there
    $requiredFields = array(
        'price',
        'name',
        'description',
        'type',
    );
    
    $valid = true;

    foreach ($products as $rawProduct) {
	
        $fields = array_keys($rawProduct);
    
    	foreach ($requiredFields as $requiredField) {
            if (!in_array($requiredField, $fields)) {
                $valid = false;
            }
        }
    }

    return $valid;
}
?>

// ---------------- REWRITTEN

<?php
function validateProductList($products)
{
    $invalidProducts = array_filter($products, 'isInvalidProduct');

    return (count($invalidProducts) === 0);
}

function isInvalidProduct($rawProduct)
{
    $requiredFields = array('price', 'name', 'description', 'type');

    $fields = array_keys($rawProduct);
    $missingFields = array_diff($requiredFields, $fields);

    return (count($missingFields) > 0);
}
?>