listener.php

<?php
function injectLogoLink($e)
{
    $halEntity = $e->getParam('entity');
    $halEntity->getLinks()->add(\ZF\Hal\Link\Link::factory(
        'rel' => 'logo',
        'route' => array(
            'name' => 'cart-logo',
            'params' => array(
                'id' => $halEntity->id,
            ),
        ),
    ));
}