featuredimage.plugin.php

public function filter_post_featuredimage_image($featuredimage_image, $post)
  {
    if ($post->content_type == Post::type('entry')) {
      if (!empty($post->info->featuredimage_image)) {
        return $post->info->featuredimage_image;
      }

      preg_match_all('/<img.+src=[\'"]([^\'"]+)[\'"].*>/i', $post->content, $matches);

      if (sizeof($matches[1]) > 0) {
        return $matches [1] [0];
      } 
    }
    return $featuredimage_image;
  }