This Wordpress plugin isn't creating links correctly

Question

To get my PHP and Wordpress skills, I've been trying to code a small plugin a day. Today's project was to create a plugin that searched over every word in my posts, checked if http://reddit.com/r/$word was a valid link, and added the link to the word if it was.

The plugin works correctly for the first post.

"**trees**" links to **http://reddit.com/r/trees**

"**php**" links to **http://reddit.com/r/php**

However, for every other post, the $word variable does not change.

"**trees**" links to **http://reddit.com/r/$word**

"**php**" links to **http://reddit.com/r/$word**

I've been scratching my head for the past hour trying to get this plugin to work. Here's the code:

add_filter('the_content', 'subreddit_replacer');

function subreddit_replacer($content) {


  global $id;
  $post_id = get_post($id);
  $post_content = $post_id -> post_content;
  //delete_post_meta($id, 'jordan'); die;
  $derp = get_post_meta($id, 'jordan');

  if (empty($derp)) {
  $words = preg_split('@[\W]+@',$post_content);
  $derp = array();
  foreach ($words as $word) {

    $link = "http://reddit.com/r/$word";
    $x = get_headers($link);
    $wordf = ($x[6] == 'HTTP/1.0 200 OK') ? '<a href= "' . $link . '" >' . $word . '</a>' : $word;
    $derp[] = $wordf;

  }
    add_post_meta($id, 'jordan', $derp, 1);
  }

  $derp = is_array($derp[0]) ? $derp[0]: $derp;

  return implode($derp, " ");

}

Any guesses on what this problem could be?

Answer 1

Stop! Stop! You will make your site supper slow / can be banned on reddit (if that ever be posible).

1. You can try to use save_post and filter your post_post content body.
2. You can setup it a crop scheldules to parse your post's.

as for your code... Read about get_post_meta last optional attribute there is difference in return if you will use that last attribute. Thats can be a problem isn't it?