class views_handler_field_date

class views_handler_field_date extends views_handler_field {
  
  /**
   * {@inheritdoc}
   */
  public function option_definition() {
    $options = parent::option_definition();
    $options['date_format'] = array(
      'default' => 'small',
    );
    $options['custom_date_format'] = array(
      'default' => '',
    );
    $options['second_date_format_custom'] = array(
      'default' => '',
    );
    $options['second_date_format'] = array(
      'default' => 'small',
    );
    $options['timezone'] = array(
      'default' => '',
    );
    return $options;
  }
  
  /**
   * {@inheritdoc}
   */
  public function options_form(&$form, &$form_state) {
    $date_formats = array();
    $date_types = system_get_date_types();
    foreach ($date_types as $value) {
      $date_formats[$value['type']] = t('@date_format format', array(
        '@date_format' => $value['title'],
      )) . ': ' . format_date(REQUEST_TIME, $value['type']);
    }
    $form['date_format'] = array(
      '#type' => 'select',
      '#title' => t('Date format'),
      '#options' => $date_formats + array(
        'custom' => t('Custom'),
        'raw time ago' => t('Time ago'),
        'time ago' => t('Time ago (with "ago" appended)'),
        'today time ago' => t('Time ago (with "ago" appended) for today\'s date, but not for other dates'),
        'raw time hence' => t('Time hence'),
        'time hence' => t('Time hence (with "hence" appended)'),
        'raw time span' => t('Time span (future dates have "-" prepended)'),
        'inverse time span' => t('Time span (past dates have "-" prepended)'),
        'time span' => t('Time span (with "ago/hence" appended)'),
      ),
      '#default_value' => isset($this->options['date_format']) ? $this->options['date_format'] : 'small',
    );
    $form['custom_date_format'] = array(
      '#type' => 'textfield',
      '#title' => t('Custom date format'),
      '#description' => t('If "Custom", see the <a href="@url" target="_blank">PHP manual</a> for date formats. Otherwise, enter the number of different time units to display, which defaults to 2.', array(
        '@url' => 'http://php.net/manual/function.date.php',
      )),
      '#default_value' => isset($this->options['custom_date_format']) ? $this->options['custom_date_format'] : '',
      '#dependency' => array(
        'edit-options-date-format' => $this->supported_date_types(),
      ),
    );
    $form['second_date_format'] = array(
      '#type' => 'select',
      '#title' => t('Second date format'),
      '#options' => $date_formats + array(
        'custom' => t('Custom'),
      ),
      '#description' => t('The date format which will be used for rendering dates other than today.'),
      '#default_value' => isset($this->options['second_date_format']) ? $this->options['second_date_format'] : 'small',
      '#dependency' => array(
        'edit-options-date-format' => array(
          'today time ago',
        ),
      ),
    );
    $form['second_date_format_custom'] = array(
      '#type' => 'textfield',
      '#title' => t('Custom date format of second date'),
      '#description' => t('If "Custom" is selected in "Second date format", see the <a href="@url" target="_blank">PHP manual</a> for date formats. Otherwise, enter the number of different time units to display, which defaults to 2.', array(
        '@url' => 'http://php.net/manual/function.date.php',
      )),
      '#default_value' => isset($this->options['second_date_format_custom']) ? $this->options['second_date_format_custom'] : '',
      // We have to use states instead of ctools dependency because dependency
      // doesn't handle multiple conditions.
'#states' => array(
        'visible' => array(
          '#edit-options-date-format' => array(
            'value' => 'today time ago',
          ),
          '#edit-options-second-date-format' => array(
            'value' => 'custom',
          ),
        ),
      ),
      // We have to use ctools dependency too because states doesn't add the
      // correct left margin to the element's wrapper.
'#dependency' => array(
        // This condition is handled by form API's states.
        // @code
        // 'edit-options-date-format' => array('today time ago'),
        // @endcode
'edit-options-second-date-format' => array(
          'custom',
        ),
      ),
    );
    $form['timezone'] = array(
      '#type' => 'select',
      '#title' => t('Timezone'),
      '#description' => t('Timezone to be used for date output.'),
      '#options' => array(
        '' => t('- Default site/user timezone -'),
      ) + system_time_zones(FALSE),
      '#default_value' => $this->options['timezone'],
      '#dependency' => array(
        'edit-options-date-format' => array_merge(array(
          'custom',
        ), array_keys($date_formats)),
      ),
    );
    parent::options_form($form, $form_state);
  }
  
  /**
   * Provide a list of all of the supported standard date types.
   *
   * @return array
   *   The list of supported formats.
   */
  private function supported_date_types() {
    return array(
      'custom',
      'raw time ago',
      'time ago',
      'today time ago',
      'raw time hence',
      'time hence',
      'raw time span',
      'time span',
      'raw time span',
      'inverse time span',
      'time span',
    );
  }
  
  /**
   * {@inheritdoc}
   */
  public function render($values) {
    $value = $this->get_value($values);
    // If the value isn't numeric, assume it's an SQL DATETIME.
    if (!empty($value) && !is_numeric($value)) {
      $value = strtotime($value);
    }
    if ($value) {
      $format = $this->options['date_format'];
      // The custom format can be either a number or a string, depending upon
      // what format is being used.
      $custom_format = NULL;
      if (in_array($format, $this->supported_date_types())) {
        $custom_format = $this->options['custom_date_format'];
      }
      $timezone = !empty($this->options['timezone']) ? $this->options['timezone'] : NULL;
      // Will be positive for a datetime in the past (ago), and negative for a
      // datetime in the future (hence).
      $time_diff = REQUEST_TIME - $value;
      switch ($format) {
        case 'raw time ago':
          return format_interval($time_diff, is_numeric($custom_format) ? $custom_format : 2);
        case 'time ago':
          $t_args = array(
            '%time' => format_interval($time_diff, is_numeric($custom_format) ? $custom_format : 2),
          );
          return t('%time ago', $t_args);
        case 'today time ago':
          $second_format = $this->options['second_date_format'];
          $second_custom_format = $this->options['second_date_format_custom'];
          if (format_date(REQUEST_TIME, 'custom', 'Y-m-d', $timezone) == format_date($value, 'custom', 'Y-m-d', $timezone)) {
            return t('%time ago', array(
              '%time' => format_interval($time_diff, is_numeric($custom_format) ? $custom_format : 2),
            ));
          }
          elseif ($second_format == 'custom') {
            if ($second_custom_format == 'r') {
              return format_date($value, $second_format, $second_custom_format, $timezone, 'en');
            }
            return format_date($value, $second_format, $second_custom_format, $timezone);
          }
          else {
            return format_date($value, $this->options['second_date_format'], '', $timezone);
          }
        case 'raw time hence':
          return format_interval(-$time_diff, is_numeric($custom_format) ? $custom_format : 2);
        case 'time hence':
          return t('%time hence', array(
            '%time' => format_interval(-$time_diff, is_numeric($custom_format) ? $custom_format : 2),
          ));
        case 'raw time span':
          return ($time_diff < 0 ? '-' : '') . format_interval(abs($time_diff), is_numeric($custom_format) ? $custom_format : 2);
        case 'inverse time span':
          return ($time_diff > 0 ? '-' : '') . format_interval(abs($time_diff), is_numeric($custom_format) ? $custom_format : 2);
        case 'time span':
          return t($time_diff < 0 ? '%time hence' : '%time ago', array(
            '%time' => format_interval(abs($time_diff), is_numeric($custom_format) ? $custom_format : 2),
          ));
        case 'custom':
          if ($custom_format == 'r') {
            return format_date($value, $format, $custom_format, $timezone, 'en');
          }
          return format_date($value, $format, t($custom_format), $timezone);
        default:
          // The custom format is not used in this scenario.
          return format_date($value, $format, '', $timezone);
      }
    }
  }

}