erop

<?php

// this file is upgrade safe
// location: custom/modules/Contacts/views/view.detail.php

require_once('modules/Contacts/views/view.detail.php');

class CustomContactsViewDetail extends ContactsViewDetail {
    /**
     * @see SugarView::display()

erop

<?php
if (!empty($bean->fetched_row['id'])) {
    // Do custom logic
}