PHP slugify function

Simple PHP function I used to use to get page routes from titles. Handles common accented characters as well.

function slugify($str) {
  // Convert to lowercase and remove whitespace
  $str = strtolower(trim($str));  

  // Replace high ascii characters
  $chars = array("ä", "ö", "ü", "ß");
  $replacements = array("ae", "oe", "ue", "ss");
  $str = str_replace($chars, $replacements, $str);
  $pattern = array("/(é|è|ë|ê)/", "/(ó|ò|ö|ô)/", "/(ú|ù|ü|û)/");
  $replacements = array("e", "o", "u");
  $str = preg_replace($pattern, $replacements, $str);

  // Remove puncuation
  $pattern = array(":", "!", "?", ".", "/", "'");
  $str = str_replace($pattern, "", $str);

  // Hyphenate any non alphanumeric characters
  $pattern = array("/[^a-z0-9-]/", "/-+/");
  $str = preg_replace($pattern, "-", $str);

  return $str;
}