voku / portable-utf8

   *

   * @return string

   */

  public static function cleanup($str)

  {

    $str = (string)$str;

    if (!isset($str[0])) {

      return '';

    }

    // fixed ISO <-> UTF-8 Errors

    $str = self::fix_simple_utf8($str);

    // remove all none UTF-8 symbols

    // && remove diamond question mark (�)

    // && remove remove invisible characters (e.g. "\0")

    // && remove BOM

    // && normalize whitespace chars (but keep non-breaking-spaces)

    $str = self::clean($str, true, true, false, true);

    return (string)$str;

  }

  /**

   * Accepts a string or a array of strings and returns an array of Unicode code points.

   *

   * @return string <p>The stripped string.</p>

   */

  public static function strip_tags($str, $allowable_tags = null, $cleanUtf8 = false)

  {

    $str = (string)$str;

    if (!isset($str[0])) {

      return '';

    }

    if ($cleanUtf8 === true) {

      $str = self::clean($str);

    }

    return strip_tags($str, $allowable_tags);

  }

  /**

   * Finds position of first occurrence of a string within another, case insensitive.