Отображение PDF-файла

/**
 * Implements hook_field_formatter_info().
 */
function field_pdfdisplay_field_formatter_info() {
  return array(
    'pdf_formatter' => array(
      'label'       => t('Display PDF'),
      'field types' => array('file'),
      'settings'    => array(
        'pdf_width'  => '100%',
        'pdf_height' => '450',
        'pdf_alt'    => t('Download PDF file'),
      )
    ),
  );
}

Далее, создадим елементы формы, необходимые для определения и изменения вышеуказанных параметров:

/**
 * Implements hook_field_formatter_settings_form().
 */
function field_pdfdisplay_field_formatter_settings_form($field, $instance, $view_mode, $form, &$form_state) {
  $display = $instance['display'][$view_mode];
  $settings = $display['settings'];
  $element = array();
  $element['pdf_width'] = array(
    '#type'           => 'textfield',
    '#title'          => t('Object width'),
    '#description'    => t('Specify the width of the field to display a pdf file (use % or px)'),
    '#default_value'  => $settings['pdf_width'],
    '#required'       => TRUE,
  );
  $element['pdf_height'] = array(
    '#type'           => 'textfield',
    '#title'          => t('Object height'),
    '#description'    => t('Specify the height of the field to display a pdf file (use % or px)'),
    '#default_value'  => $settings['pdf_height'],
    '#required'       => TRUE,
  );
  $element['pdf_alt'] = array(
    '#type'           => 'textfield',
    '#title'          => t('Text for download'),
    '#description'    => t('Specify the text that will appear to download the file'),
    '#default_value'  => $settings['pdf_alt'],
    '#required'       => TRUE,
  );
  return $element;
}

Следующим шагом является вывод сообщения, в котором будет содержаться информация о наших настройках:

/**
 * Implements hook_field_formatter_settings_summary().
 */
function field_pdfdisplay_field_formatter_settings_summary($field, $instance, $view_mode) {
  $display  = $instance['display'][$view_mode];
  $settings = $display['settings'];
  $summary  = t('Region of @width to @height, and text at download link - "@alt"', array(
    '@width'  => $settings['pdf_width'],
    '@height' => $settings['pdf_height'],
    '@alt'    => $settings['pdf_alt'],
  ));
  return $summary;
}

И в завершении, самый главный момент - генерация вывода файла:

/**
 * Implements hook_field_formatter_view().
 */
function field_pdfdisplay_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  global $base_url;  
  $settings = $display['settings'];
  $element  = array();
  $width    = $settings['pdf_width'];
  $height   = $settings['pdf_height'];
  $alt      = $settings['pdf_alt'];
  $path     = $base_url . '/' . variable_get('file_public_path') . substr($items[0]['uri'], 8);
  $object   = '

';
  $element[0]['#markup'] = $object;
  return $element;
}