<?php

/**
 * @file
 * Display Suite Format
 */

/**
 * Implements hook_filter_info().
 */
function ds_format_filter_info() {
  $filters['ds_code'] = array(
    'title' => t('Display Suite evaluator'),
    'description' => t('This filter will only work in the Display Suite text format, machine name is <em>ds_code</em>. No other filters can be enabled either.'),
    'process callback' => 'ds_format_php_eval',
    'tips callback' => 'ds_format_filter_tips',
    'cache' => FALSE,
  );
  return $filters;
}

/**
 * Tips callback for Display Suite php filter.
 */
function ds_format_filter_tips($filter, $format, $long = FALSE) {
  global $base_url;
  if ($long) {
    $output = '<h4>' . t('Using custom code with Display Suite') . '</h4>';
    $output .= t('Include &lt;?php ?&gt; tags when using PHP. The $entity object is available.');
    return $output;
  }
  else {
    return t('You may post Display Suite code. You should include &lt;?php ?&gt; tags when using PHP. The $entity object is available.');
  }
}

/**
 * Wrapper function around PHP eval(). We don't use php_eval from
 * the PHP module because custom fields might need properties from
 * the current entity.
 *
 * @param $code
 *   The code to evaluate from the custom field.
 * @param $object
 *   An object to use for evaluation.
 * @return $output
 *   The output from eval.
 */
function ds_format_php_eval($code, $entity, $build = array()) {
  global $theme_path, $theme_info, $conf;

  // Store current theme path.
  $old_theme_path = $theme_path;

  // Restore theme_path to the theme, as long as ds_php_eval() executes,
  // so code evaluted will not see the caller module as the current theme.
  // If theme info is not initialized get the path from theme_default.
  if (!isset($theme_info)) {
    $theme_path = drupal_get_path('theme', $conf['theme_default']);
  }
  else {
    $theme_path = dirname($theme_info->filename);
  }

  ob_start();
  print eval('?>' . $code);
  $output = ob_get_contents();
  ob_end_clean();

  // Recover original theme path.
  $theme_path = $old_theme_path;

  return $output;
}