Php function not working

function get_products()
{
    $query = query(" SELECT * FROM products");

    confirm($query);

    while($row = fetch_array($query))
    {
        $product = <<<DELIMETER

            <div class="col-sm-4 col-lg-4 col-md-4">
                <div class="thumbnail">
                    <img src="http://placehold.it/320x150" alt="">
                    <div class="caption">
                        <h4 class="pull-right">{$row['product_price']}</h4>
                        <h4><a href="#">Fifth Product</a>
                        </h4>
                        <p>This is a short description. Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
                        <a class="btn btn-primary" target="_blank" href="http://maxoffsky.com/code-blog/laravel-shop-tutorial-1-building-a-review-system/">View Tutorial</a>
                    </div>
                    
                </div>
            </div>
DELIMETER;

echo $product;
     
    }
}

<?php
require_once("../resources/config.php");
?>
<?php
include(TEMPLATE_FRONT . DS . "header.php");
?>
    <!-- Page Content -->
    <div class="container">

        <div class="row">

            <?php
            include(TEMPLATE_FRONT . DS . "side_nav.php");
            ?>

            <div class="col-md-9">

                <div class="row carousel-holder">

                    <div class="col-md-12">
                        <?php
                        include(TEMPLATE_FRONT . DS . "slider.php");
                        ?>
                    </div>

                </div>

                <div class="row">

                    <?php
                    get_products();
                    ?>

                </div> <!--  Row ends here -->

            </div>

        </div>

    </div>
    <!-- /.container -->

<?php
include(TEMPLATE_FRONT . DS . "footer.php");
?>

<?php

ob_start();

session_start();

//Rout constant
defined("DS") ? null : define("DS", DIRECTORY_SEPARATOR);
//Templates constant
defined("TEMPLATE_FRONT") ? null : define("TEMPLATE_FRONT", __DIR__ . DS . "template/front");
defined("TEMPLATE_BACK") ? null : define("TEMPLATE_BACK", __DIR__ . DS . "template/back");
//DB Connection constant
defined("DB_HOST") ? null : define("DB_HOST", "localhost");
defined("DB_USER") ? null : define("DB_USER", "root");

defined("DB_PASS") ? null : define("DB_PASS", "mysql");
defined("DB_NAME") ? null : define("DB_NAME", "ecom_db");

$connection = mysqli_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);

require_once("functions.php");