<?php
/**
* @desc
* Sort arrays with multibyte values using a predefined or custom alphabet.
*
* @author Christian Reinecke <reinecke@bajoodoo.de>
* @version 1.1
* @since 2009-01-15
*
* @example
* <code>
* // quick
* $array = array("Zebra", "Engländer", "England", "Chinese", "Äffchen", "Überseeboot",
* "Unterseeboot", "ß", "Sz", "Bürger", "Burger", "burger", "bürger", "ÄÖÜ");
* AIS_Util_MultibyteSort::staticSort($array);
* print_r($array);
* // Array (
* // [0] => Äffchen [1] => ÄÖÜ [2] => Burger [3] => Bürger [4] => burger [5] => bürger
* // [6] => Chinese [7] => England [8] => Engländer [9] => Sz [10] => ß [11] => Unterseeboot
* // [12] => Überseeboot [13] => Zebra
* // )
*
*
* // with custom setup
* $mbsort = new AIS_Util_MultibyteSort("UTF-8", true);
* $mbsort->sort($array);
* print_r($array)
* // same result as above
* $mbsort->sort($otherArray);
* </code>
*
* @todo
* This class can not handle unknown special characters (fallback to default behaviour),
* which makes it desirable to find a global, sorted alphabet. Feel free to add more special chars.
*
* Don't forget to send the correct charset in your header
* <code>
* header("Content-type: text/html; charset=utf-8");
* </code>
*/
class AIS_Util_MultibyteSort
{
const EncodingUtf8 = "UTF-8";
const EncodingDefault = self::EncodingUtf8;
const CasePreferenceUpper = true;
const CasePreferenceLower = false;
const CasePreferenceDefault = self::CasePreferenceUpper;
protected static $instances = array();
protected static $alphabetLoose = array("A" => "Ä", "a" => "äà", "O" => "Ö", "o" => "ö", "U" => "Ü",
"u" => "ü", "s" => "ß");
/**
* multibyte encoding
* @see self::EncodingDefault
* @var string
*/
protected $encoding;
/**
* array map (single special char => ASCII-128)
* @var array
*/
protected $alphabet;
/**
* case flag, whether upper case chars are preferred to lower case chars
* @see self::CasePreferenceDefault
* @var bool
*/
protected $case;
/**
* @param array|string [optional] loose alphabet or key for predefined loose alphabet
* @param string [optional] encoding for multibyte functions
* @param bool [optional] prefer uppercase char to lower-case (Aa or aA)
*/
public function __construct($encoding = self::EncodingDefault, $preferUpperCase = self::CasePreferenceDefault)
{
$this->setEncoding($encoding);
$this->setUpperCasePreference($preferUpperCase);
$this->loadAlphabet();
}
/**
* @desc
* The instance for all static calls is stored in a static property, so you can use the
* instance once again. But if you prefer to use this class only once, use the __construct
* method. There's no overhead then.
*/
public static function getInstance($encoding = self::EncodingDefault, $preferUpperCase = self::CasePreferenceDefault)
{
$hash = crc32($encoding . $preferUpperCase);
if (!array_key_exists($hash, self::$instances)) {
self::$instances[$hash] = new self($encoding, $preferUpperCase);
}
return self::$instances[$hash];
}
/**
* @desc shortcut
*/
public static function sortStatic(&$array, $encoding = self::EncodingDefault, $preferUpperCase = self::CasePreferenceDefault)
{
$self = self::getInstance($encoding, $preferUpperCase);
$self->sort($array);
}
public static function asortStatic(&$array, $encoding = self::EncodingDefault, $preferUpperCase = self::CasePreferenceDefault)
{
$self = self::getInstance($encoding, $preferUpperCase);
$self->asort($array);
}
/**
* @desc sort array with the constructor-given settings
*/
public function sort(&$array)
{
/**
* Got this message: "Warning: usort() [function.usort]: Invalid comparison function"?
* Then do not call this method from a static context and change your error_reporting level
* to E_ALL | E_STRICT.
*/
usort($array, array($this, "sortString"));
}
public function asort(&$array)
{
uasort($array, array($this, "sortString"));
}
/**
* @desc multibyte string compare (something like we would expect behind mb_strcmp())
* @return int sort order value (1, 0, -1)
*/
protected function sortString($a, $b)
{
$ax = mb_strlen($a, $this->encoding);
$bx = mb_strlen($b, $this->encoding);
for ($i = 0, $x = min($ax, $bx); $i < $x; ++$i) {
$result = $this->charCmp(mb_substr($a, $i, 1, $this->encoding),
mb_substr($b, $i, 1, $this->encoding));
if ($result != 0) {
return $result;
}
}
return $this->intCmp($ax, $bx);
}
/**
* @desc integer compare
* @return int sort order value (-1, 0, 1)
*/
protected function intCmp($a, $b)
{
return ($a == $b) ? 0 : ($a < $b ? -1 : 1);
}
/**
* @desc multibyte char compare
* @return int sort order value (-1, 0, 1)
*/
protected function charCmp($a, $b)
{
// check if characters are known as special chars
$ai = isset($this->alphabet[$a]); // ai = a isset
$bi = isset($this->alphabet[$b]);
if ($ai && $bi) {
// both are known special chars
$ar = $this->alphabet[$a]; // ar = a representation (ASCII-128)
$br = $this->alphabet[$b];
$result = $this->charCaseCmp($ar, $br);
if ($result == 0 && $a != $b) {
// they aren't equal, but their representation is, so check position in original array
$ap = mb_strpos(self::$alphabetLoose[$ar], $a, 0, $this->encoding);
$bp = mb_strpos(self::$alphabetLoose[$br], $b, 0, $this->encoding);
$result = $this->intCmp($ap, $bp);
}
} else if ($ai) {
// $a is a known special char, $b not
$result = $this->charCaseCmp($this->alphabet[$a], $b);
// so they are not equal, $result = 0 means $b is "smaller"
$result = ($result == 0) ? 1 : $result;
} else if ($bi) {
// $b is a known special char, $a not
$result = $this->charCaseCmp($a, $this->alphabet[$b]);
// so they are not equal; $result = 0 means $a is "smaller"
$result = ($result == 0) ? -1 : $result;
} else {
// both are unknown characters
$result = $this->charCaseCmp($a, $b);
}
return $result;
}
/**
* @desc multibyte char case compare
* @return sort order value (-1, 0, 1)
*/
protected function charCaseCmp($a, $b)
{
if ($a == $b) {
// they are equal, no check required
return 0;
}
$A = mb_strtoupper($a, $this->encoding);
$B = mb_strtoupper($b, $this->encoding);
$result = strcmp($A, $B);
if ($result == 0) {
// their mb_strtoupper() value is equal, select compare value depending on case preference
$result = ($A != $a) ? $this->case : ($this->case * -1);
}
return $result;
}
protected function loadAlphabet()
{
if (empty($this->alphabet)) {
// load only once per instance
// $alphabetLoose is required to differ between special chars with the same ASCII-128 representation
foreach (self::$alphabetLoose as $order => $char) {
for ($i = 0, $x = mb_strlen($char, $this->encoding); $i < $x; ++$i) {
// use each multibyte char as key with its ASCII-128 representation as key
$this->alphabet[mb_substr($char, $i, 1, $this->encoding)] = $order;
}
}
}
}
protected function setEncoding($encoding)
{
$this->encoding = $encoding;
}
protected function setUpperCasePreference($preferUpperCase)
{
$this->case = $preferUpperCase ? 1 : -1;
}
}
?>
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