<?php
/**
* Zend Framework (http://framework.zend.com/)
*
* @link http://github.com/zendframework/zf2 for the canonical source repository
* @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
namespace Zend\Json;
use stdClass;
use Zend\Json\Exception\InvalidArgumentException;
use Zend\Json\Exception\RuntimeException;
/**
* Decode JSON encoded string to PHP variable constructs
*/
class Decoder
{
/**
* Parse tokens used to decode the JSON object. These are not
* for public consumption, they are just used internally to the
* class.
*/
const EOF = 0;
const DATUM = 1;
const LBRACE = 2;
const LBRACKET = 3;
const RBRACE = 4;
const RBRACKET = 5;
const COMMA = 6;
const COLON = 7;
/**
* Use to maintain a "pointer" to the source being decoded
*
* @var string
*/
protected $source;
/**
* Caches the source length
*
* @var int
*/
protected $sourceLength;
/**
* The offset within the source being decoded
*
* @var int
*
*/
protected $offset;
/**
* The current token being considered in the parser cycle
*
* @var int
*/
protected $token;
/**
* Flag indicating how objects should be decoded
*
* @var int
* @access protected
*/
protected $decodeType;
/**
* @var $_tokenValue
*/
protected $tokenValue;
/**
* Constructor
*
* @param string $source String source to decode
* @param int $decodeType How objects should be decoded -- see
* {@link Zend\Json\Json::TYPE_ARRAY} and {@link Zend\Json\Json::TYPE_OBJECT} for
* valid values
* @throws InvalidArgumentException
*/
protected function __construct($source, $decodeType)
{
// Set defaults
$this->source = self::decodeUnicodeString($source);
$this->sourceLength = strlen($this->source);
$this->token = self::EOF;
$this->offset = 0;
switch ($decodeType) {
case Json::TYPE_ARRAY:
case Json::TYPE_OBJECT:
$this->decodeType = $decodeType;
break;
default:
throw new InvalidArgumentException("Unknown decode type '{$decodeType}', please use one of the constants Json::TYPE_*");
}
// Set pointer at first token
$this->_getNextToken();
}
/**
* Decode a JSON source string
*
* Decodes a JSON encoded string. The value returned will be one of the
* following:
* - integer
* - float
* - boolean
* - null
* - stdClass
* - array
* - array of one or more of the above types
*
* By default, decoded objects will be returned as associative arrays; to
* return a stdClass object instead, pass {@link Zend\Json\Json::TYPE_OBJECT} to
* the $objectDecodeType parameter.
*
* @static
* @access public
* @param string $source String to be decoded
* @param int $objectDecodeType How objects should be decoded; should be
* either or {@link Zend\Json\Json::TYPE_ARRAY} or
* {@link Zend\Json\Json::TYPE_OBJECT}; defaults to TYPE_ARRAY
* @return mixed
*/
public static function decode($source, $objectDecodeType = Json::TYPE_OBJECT)
{
$decoder = new static($source, $objectDecodeType);
return $decoder->_decodeValue();
}
/**
* Recursive driving routine for supported toplevel tops
*
* @return mixed
*/
protected function _decodeValue()
{
switch ($this->token) {
case self::DATUM:
$result = $this->tokenValue;
$this->_getNextToken();
return($result);
break;
case self::LBRACE:
return($this->_decodeObject());
break;
case self::LBRACKET:
return($this->_decodeArray());
break;
default:
return null;
break;
}
}
/**
* Decodes an object of the form:
* { "attribute: value, "attribute2" : value,...}
*
* If Zend\Json\Encoder was used to encode the original object then
* a special attribute called __className which specifies a class
* name that should wrap the data contained within the encoded source.
*
* Decodes to either an array or stdClass object, based on the value of
* {@link $decodeType}. If invalid $decodeType present, returns as an
* array.
*
* @return array|stdClass
* @throws RuntimeException
*/
protected function _decodeObject()
{
$members = array();
$tok = $this->_getNextToken();
while ($tok && $tok != self::RBRACE) {
if ($tok != self::DATUM || ! is_string($this->tokenValue)) {
throw new RuntimeException('Missing key in object encoding: ' . $this->source);
}
$key = $this->tokenValue;
$tok = $this->_getNextToken();
if ($tok != self::COLON) {
throw new RuntimeException('Missing ":" in object encoding: ' . $this->source);
}
$tok = $this->_getNextToken();
$members[$key] = $this->_decodeValue();
$tok = $this->token;
if ($tok == self::RBRACE) {
break;
}
if ($tok != self::COMMA) {
throw new RuntimeException('Missing "," in object encoding: ' . $this->source);
}
$tok = $this->_getNextToken();
}
switch ($this->decodeType) {
case Json::TYPE_OBJECT:
// Create new stdClass and populate with $members
$result = new stdClass();
foreach ($members as $key => $value) {
if ($key === '') {
$key = '_empty_';
}
$result->$key = $value;
}
break;
case Json::TYPE_ARRAY:
default:
$result = $members;
break;
}
$this->_getNextToken();
return $result;
}
/**
* Decodes a JSON array format:
* [element, element2,...,elementN]
*
* @return array
* @throws RuntimeException
*/
protected function _decodeArray()
{
$result = array();
$tok = $this->_getNextToken(); // Move past the '['
$index = 0;
while ($tok && $tok != self::RBRACKET) {
$result[$index++] = $this->_decodeValue();
$tok = $this->token;
if ($tok == self::RBRACKET || !$tok) {
break;
}
if ($tok != self::COMMA) {
throw new RuntimeException('Missing "," in array encoding: ' . $this->source);
}
$tok = $this->_getNextToken();
}
$this->_getNextToken();
return $result;
}
/**
* Removes whitespace characters from the source input
*/
protected function _eatWhitespace()
{
if (preg_match(
'/([\t\b\f\n\r ])*/s',
$this->source,
$matches,
PREG_OFFSET_CAPTURE,
$this->offset)
&& $matches[0][1] == $this->offset)
{
$this->offset += strlen($matches[0][0]);
}
}
/**
* Retrieves the next token from the source stream
*
* @return int Token constant value specified in class definition
* @throws RuntimeException
*/
protected function _getNextToken()
{
$this->token = self::EOF;
$this->tokenValue = null;
$this->_eatWhitespace();
if ($this->offset >= $this->sourceLength) {
return(self::EOF);
}
$str = $this->source;
$strLength = $this->sourceLength;
$i = $this->offset;
$start = $i;
switch ($str{$i}) {
case '{':
$this->token = self::LBRACE;
break;
case '}':
$this->token = self::RBRACE;
break;
case '[':
$this->token = self::LBRACKET;
break;
case ']':
$this->token = self::RBRACKET;
break;
case ',':
$this->token = self::COMMA;
break;
case ':':
$this->token = self::COLON;
break;
case '"':
$result = '';
do {
$i++;
if ($i >= $strLength) {
break;
}
$chr = $str{$i};
if ($chr == '\\') {
$i++;
if ($i >= $strLength) {
break;
}
$chr = $str{$i};
switch ($chr) {
case '"' :
$result .= '"';
break;
case '\\':
$result .= '\\';
break;
case '/' :
$result .= '/';
break;
case 'b' :
$result .= "\x08";
break;
case 'f' :
$result .= "\x0c";
break;
case 'n' :
$result .= "\x0a";
break;
case 'r' :
$result .= "\x0d";
break;
case 't' :
$result .= "\x09";
break;
case '\'' :
$result .= '\'';
break;
default:
throw new RuntimeException("Illegal escape sequence '{$chr}'");
}
} elseif ($chr == '"') {
break;
} else {
$result .= $chr;
}
} while ($i < $strLength);
$this->token = self::DATUM;
//$this->tokenValue = substr($str, $start + 1, $i - $start - 1);
$this->tokenValue = $result;
break;
case 't':
if (($i+ 3) < $strLength && substr($str, $start, 4) == "true") {
$this->token = self::DATUM;
}
$this->tokenValue = true;
$i += 3;
break;
case 'f':
if (($i+ 4) < $strLength && substr($str, $start, 5) == "false") {
$this->token = self::DATUM;
}
$this->tokenValue = false;
$i += 4;
break;
case 'n':
if (($i+ 3) < $strLength && substr($str, $start, 4) == "null") {
$this->token = self::DATUM;
}
$this->tokenValue = NULL;
$i += 3;
break;
}
if ($this->token != self::EOF) {
$this->offset = $i + 1; // Consume the last token character
return($this->token);
}
$chr = $str{$i};
if ($chr == '-' || $chr == '.' || ($chr >= '0' && $chr <= '9')) {
if (preg_match('/-?([0-9])*(\.[0-9]*)?((e|E)((-|\+)?)[0-9]+)?/s',
$str, $matches, PREG_OFFSET_CAPTURE, $start) && $matches[0][1] == $start) {
$datum = $matches[0][0];
if (is_numeric($datum)) {
if (preg_match('/^0\d+$/', $datum)) {
throw new RuntimeException("Octal notation not supported by JSON (value: {$datum})");
} else {
$val = intval($datum);
$fVal = floatval($datum);
$this->tokenValue = ($val == $fVal ? $val : $fVal);
}
} else {
throw new RuntimeException("Illegal number format: {$datum}");
}
$this->token = self::DATUM;
$this->offset = $start + strlen($datum);
}
} else {
throw new RuntimeException('Illegal Token');
}
return $this->token;
}
/**
* Decode Unicode Characters from \u0000 ASCII syntax.
*
* This algorithm was originally developed for the
* Solar Framework by Paul M. Jones
*
* @link http://solarphp.com/
* @link https://github.com/solarphp/core/blob/master/Solar/Json.php
* @param string $chrs
* @return string
*/
public static function decodeUnicodeString($chrs)
{
$chrs = (string) $chrs;
$utf8 = '';
$strlenChrs = strlen($chrs);
for ($i = 0; $i < $strlenChrs; $i++) {
$ordChrsC = ord($chrs[$i]);
switch (true) {
case preg_match('/\\\u[0-9A-F]{4}/i', substr($chrs, $i, 6)):
// single, escaped unicode character
$utf16 = chr(hexdec(substr($chrs, ($i + 2), 2)))
. chr(hexdec(substr($chrs, ($i + 4), 2)));
$utf8char = self::_utf162utf8($utf16);
$search = array('\\', "\n", "\t", "\r", chr(0x08), chr(0x0C), '"', '\'', '/');
if (in_array($utf8char, $search)) {
$replace = array('\\\\', '\\n', '\\t', '\\r', '\\b', '\\f', '\\"', '\\\'', '\\/');
$utf8char = str_replace($search, $replace, $utf8char);
}
$utf8 .= $utf8char;
$i += 5;
break;
case ($ordChrsC >= 0x20) && ($ordChrsC <= 0x7F):
$utf8 .= $chrs{$i};
break;
case ($ordChrsC & 0xE0) == 0xC0:
// characters U-00000080 - U-000007FF, mask 110XXXXX
//see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
$utf8 .= substr($chrs, $i, 2);
++$i;
break;
case ($ordChrsC & 0xF0) == 0xE0:
// characters U-00000800 - U-0000FFFF, mask 1110XXXX
// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
$utf8 .= substr($chrs, $i, 3);
$i += 2;
break;
case ($ordChrsC & 0xF8) == 0xF0:
// characters U-00010000 - U-001FFFFF, mask 11110XXX
// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
$utf8 .= substr($chrs, $i, 4);
$i += 3;
break;
case ($ordChrsC & 0xFC) == 0xF8:
// characters U-00200000 - U-03FFFFFF, mask 111110XX
// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
$utf8 .= substr($chrs, $i, 5);
$i += 4;
break;
case ($ordChrsC & 0xFE) == 0xFC:
// characters U-04000000 - U-7FFFFFFF, mask 1111110X
// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
$utf8 .= substr($chrs, $i, 6);
$i += 5;
break;
}
}
return $utf8;
}
/**
* Convert a string from one UTF-16 char to one UTF-8 char.
*
* Normally should be handled by mb_convert_encoding, but
* provides a slower PHP-only method for installations
* that lack the multibyte string extension.
*
* This method is from the Solar Framework by Paul M. Jones
*
* @link http://solarphp.com
* @param string $utf16 UTF-16 character
* @return string UTF-8 character
*/
protected static function _utf162utf8($utf16)
{
// Check for mb extension otherwise do by hand.
if (function_exists('mb_convert_encoding')) {
return mb_convert_encoding($utf16, 'UTF-8', 'UTF-16');
}
$bytes = (ord($utf16{0}) << 8) | ord($utf16{1});
switch (true) {
case ((0x7F & $bytes) == $bytes):
// this case should never be reached, because we are in ASCII range
// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
return chr(0x7F & $bytes);
case (0x07FF & $bytes) == $bytes:
// return a 2-byte UTF-8 character
// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
return chr(0xC0 | (($bytes >> 6) & 0x1F))
. chr(0x80 | ($bytes & 0x3F));
case (0xFFFF & $bytes) == $bytes:
// return a 3-byte UTF-8 character
// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
return chr(0xE0 | (($bytes >> 12) & 0x0F))
. chr(0x80 | (($bytes >> 6) & 0x3F))
. chr(0x80 | ($bytes & 0x3F));
}
// ignoring UTF-32 for now, sorry
return '';
}
}