class UTF8Utils in Zircon Profile 8

UTF-8 Utilities

Hierarchy

• class \Masterminds\HTML5\Parser\UTF8Utils

2 files declare their use of UTF8Utils

TokenizerTest.php in vendor/masterminds/html5/test/HTML5/Parser/TokenizerTest.php

UTF8UtilsTest.php in vendor/masterminds/html5/test/HTML5/Parser/UTF8UtilsTest.php

File

vendor/masterminds/html5/src/HTML5/Parser/UTF8Utils.php, line 32

Namespace

Masterminds\HTML5\Parser

class UTF8Utils {

  /**
   * The Unicode replacement character..
   */
  const FFFD = "�";

  /**
   * Count the number of characters in a string.
   *
   * UTF-8 aware. This will try (in order) iconv,
   * MB, libxml, and finally a custom counter.
   *
   * @todo Move this to a general utility class.
   */
  public static function countChars($string) {

    // Get the length for the string we need.
    if (function_exists('iconv_strlen')) {
      return iconv_strlen($string, 'utf-8');
    }
    elseif (function_exists('mb_strlen')) {
      return mb_strlen($string, 'utf-8');
    }
    elseif (function_exists('utf8_decode')) {

      // MPB: Will this work? Won't certain decodes lead to two chars
      // extrapolated out of 2-byte chars?
      return strlen(utf8_decode($string));
    }
    $count = count_chars($string);

    // 0x80 = 0x7F - 0 + 1 (one added to get inclusive range)
    // 0x33 = 0xF4 - 0x2C + 1 (one added to get inclusive range)
    return array_sum(array_slice($count, 0, 0x80)) + array_sum(array_slice($count, 0xc2, 0x33));
  }

  /**
   * Convert data from the given encoding to UTF-8.
   *
   * This has not yet been tested with charactersets other than UTF-8.
   * It should work with ISO-8859-1/-13 and standard Latin Win charsets.
   *
   * @param string $data
   *            The data to convert.
   * @param string $encoding
   *            A valid encoding. Examples: http://www.php.net/manual/en/mbstring.supported-encodings.php
   */
  public static function convertToUTF8($data, $encoding = 'UTF-8') {

    /*
     * From the HTML5 spec: Given an encoding, the bytes in the input stream must be converted to Unicode characters for the tokeniser, as described by the rules for that encoding, except that the leading U+FEFF BYTE ORDER MARK character, if any, must not be stripped by the encoding layer (it is stripped by the rule below). Bytes or sequences of bytes in the original byte stream that could not be converted to Unicode characters must be converted to U+FFFD REPLACEMENT CHARACTER code points.
     */

    // mb_convert_encoding is chosen over iconv because of a bug. The best
    // details for the bug are on http://us1.php.net/manual/en/function.iconv.php#108643
    // which contains links to the actual but reports as well as work around
    // details.
    if (function_exists('mb_convert_encoding')) {

      // mb library has the following behaviors:
      // - UTF-16 surrogates result in false.
      // - Overlongs and outside Plane 16 result in empty strings.
      // Before we run mb_convert_encoding we need to tell it what to do with
      // characters it does not know. This could be different than the parent
      // application executing this library so we store the value, change it
      // to our needs, and then change it back when we are done. This feels
      // a little excessive and it would be great if there was a better way.
      $save = ini_get('mbstring.substitute_character');
      ini_set('mbstring.substitute_character', "none");
      $data = mb_convert_encoding($data, 'UTF-8', $encoding);
      ini_set('mbstring.substitute_character', $save);
    }
    elseif (function_exists('iconv') && $encoding != 'auto') {

      // fprintf(STDOUT, "iconv found\n");
      // iconv has the following behaviors:
      // - Overlong representations are ignored.
      // - Beyond Plane 16 is replaced with a lower char.
      // - Incomplete sequences generate a warning.
      $data = @iconv($encoding, 'UTF-8//IGNORE', $data);
    }
    else {

      // we can make a conforming native implementation
      throw new Exception('Not implemented, please install mbstring or iconv');
    }

    /*
     * One leading U+FEFF BYTE ORDER MARK character must be ignored if any are present.
     */
    if (substr($data, 0, 3) === "") {
      $data = substr($data, 3);
    }
    return $data;
  }

  /**
   * Checks for Unicode code points that are not valid in a document.
   *
   * @param string $data
   *            A string to analyze.
   * @return array An array of (string) error messages produced by the scanning.
   */
  public static function checkForIllegalCodepoints($data) {
    if (!function_exists('preg_match_all')) {
      throw \Exception('The PCRE library is not loaded or is not available.');
    }

    // Vestigal error handling.
    $errors = array();

    /*
     * All U+0000 null characters in the input must be replaced by U+FFFD REPLACEMENT CHARACTERs. Any occurrences of such characters is a parse error.
     */
    for ($i = 0, $count = substr_count($data, "\0"); $i < $count; $i++) {
      $errors[] = 'null-character';
    }

    /*
     * Any occurrences of any characters in the ranges U+0001 to U+0008, U+000B, U+000E to U+001F, U+007F to U+009F, U+D800 to U+DFFF , U+FDD0 to U+FDEF, and characters U+FFFE, U+FFFF, U+1FFFE, U+1FFFF, U+2FFFE, U+2FFFF, U+3FFFE, U+3FFFF, U+4FFFE, U+4FFFF, U+5FFFE, U+5FFFF, U+6FFFE, U+6FFFF, U+7FFFE, U+7FFFF, U+8FFFE, U+8FFFF, U+9FFFE, U+9FFFF, U+AFFFE, U+AFFFF, U+BFFFE, U+BFFFF, U+CFFFE, U+CFFFF, U+DFFFE, U+DFFFF, U+EFFFE, U+EFFFF, U+FFFFE, U+FFFFF, U+10FFFE, and U+10FFFF are parse errors. (These are all control characters or permanently undefined Unicode characters.)
     */

    // Check PCRE is loaded.
    $count = preg_match_all('/(?:
        [\\x01-\\x08\\x0B\\x0E-\\x1F\\x7F] # U+0001 to U+0008, U+000B,  U+000E to U+001F and U+007F
      |
        \\xC2[\\x80-\\x9F] # U+0080 to U+009F
      |
        \\xED(?:\\xA0[\\x80-\\xFF]|[\\xA1-\\xBE][\\x00-\\xFF]|\\xBF[\\x00-\\xBF]) # U+D800 to U+DFFFF
      |
        \\xEF\\xB7[\\x90-\\xAF] # U+FDD0 to U+FDEF
      |
        \\xEF\\xBF[\\xBE\\xBF] # U+FFFE and U+FFFF
      |
        [\\xF0-\\xF4][\\x8F-\\xBF]\\xBF[\\xBE\\xBF] # U+nFFFE and U+nFFFF (1 <= n <= 10_{16})
      )/x', $data, $matches);
    for ($i = 0; $i < $count; $i++) {
      $errors[] = 'invalid-codepoint';
    }
    return $errors;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
UTF8Utils::checkForIllegalCodepoints	public static	function	Checks for Unicode code points that are not valid in a document.
UTF8Utils::convertToUTF8	public static	function	Convert data from the given encoding to UTF-8.
UTF8Utils::countChars	public static	function	Count the number of characters in a string.
UTF8Utils::FFFD		constant	The Unicode replacement character..