Drupal:Format download file link

gistfile1.php

/**
 * Implements hook_field_formatter_info()
 */
function MYMODULE_field_formatter_info()
{
    return array(
        // Format de téléchargement de fichier
        'MYMODULE_file_link' => array(
            'label' => t('Download link'),
            'field types' => array('file')
        ),
    );
}

/**
 * Implements hook_field_formatter_view()
 */
function MYMODYLE_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display)
{

    $element = array();
    $settings = $display['settings'];

    switch ($display['type']) {
        case 'visio_custom_file_link':
            $list = array();

            // Manage several files
            foreach ($items as $file) {
                // Get file extension
                $ext = end(explode('.', $file['filename']));

                // Generate link
                $list[] = array(
                    'data' => l(t('Download'), file_create_url($file['uri']), array(
                        'attributes' => array(
                            'class' => $ext . '-download-link',
                            'title' => $file['filename'],
                            'alt' => $file['filename'],
                        ))),
                );
            }
            $element[0] = array(
                '#theme' => 'item_list',
                '#items' => $list,
                '#attributes' => array('class' => 'download-links-list')
            );
            break;
    }

    return $element;
}