<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* Converts to and from JSON format.
*
* JSON (JavaScript Object Notation) is a lightweight data-interchange
* format. It is easy for humans to read and write. It is easy for machines
* to parse and generate. It is based on a subset of the JavaScript
* Programming Language, Standard ECMA-262 3rd Edition - December 1999.
* This feature can also be found in Python. JSON is a text format that is
* completely language independent but uses conventions that are familiar
* to programmers of the C-family of languages, including C, C++, C#, Java,
* JavaScript, Perl, TCL, and many others. These properties make JSON an
* ideal data-interchange language.
*
* This package provides a simple encoder and decoder for JSON notation. It
* is intended for use with client-side Javascript applications that make
* use of HTTPRequest to perform server communication functions - data can
* be encoded into JSON notation for use in a client-side javascript, or
* decoded from incoming Javascript requests. JSON format is native to
* Javascript, and can be directly eval()'ed with no further parsing
* overhead
*
* All strings should be in ASCII or UTF-8 format!
*
* LICENSE: Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met: Redistributions of source code must retain the
* above copyright notice, this list of conditions and the following
* disclaimer. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
* NO EVENT SHALL CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* @category
* @package Services_JSON
* @author Michal Migurski <mike-json@teczno.com>
* @author Matt Knapp <mdknapp[at]gmail[dot]com>
* @author Brett Stimmerman <brettstimmerman[at]gmail[dot]com>
* @copyright 2005 Michal Migurski
* @version CVS: $Id: JSON.php,v 1.31 2006/06/28 05:54:17 migurski Exp $
* @license http://www.opensource.org/licenses/bsd-license.php
* @link http://pear.php.net/pepr/pepr-proposal-show.php?id=198
*/
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_SLICE', 1);
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_STR', 2);
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_ARR', 3);
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_OBJ', 4);
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_CMT', 5);
/**
* Behavior switch for Services_JSON::decode()
*/
define('SERVICES_JSON_LOOSE_TYPE', 16);
/**
* Behavior switch for Services_JSON::decode()
*/
define('SERVICES_JSON_SUPPRESS_ERRORS', 32);
/**
* Converts to and from JSON format.
*
* Brief example of use:
*
* <code>
* // create a new instance of Services_JSON
* $json = new Services_JSON();
*
* // convert a complexe value to JSON notation, and send it to the browser
* $value = array('foo', 'bar', array(1, 2, 'baz'), array(3, array(4)));
* $output = $json->encode($value);
*
* print($output);
* // prints: ["foo","bar",[1,2,"baz"],[3,[4]]]
*
* // accept incoming POST data, assumed to be in JSON notation
* $input = file_get_contents('php://input', 1000000);
* $value = $json->decode($input);
* </code>
*/
class Services_JSON
{
/**
* constructs a new JSON instance
*
* @param int $use object behavior flags; combine with boolean-OR
*
* possible values:
* - SERVICES_JSON_LOOSE_TYPE: loose typing.
* "{...}" syntax creates associative arrays
* instead of objects in decode().
* - SERVICES_JSON_SUPPRESS_ERRORS: error suppression.
* Values which can't be encoded (e.g. resources)
* appear as NULL instead of throwing errors.
* By default, a deeply-nested resource will
* bubble up with an error, so all return values
* from encode() should be checked with isError()
*/
function Services_JSON($use = 0)
{
$this->use = $use;
}
/**
* 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 multibye string extension.
*
* @param string $utf16 UTF-16 character
* @return string UTF-8 character
* @access private
*/
function utf162utf8($utf16)
{
// oh please oh please oh please oh please oh please
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 '';
}
/**
* convert a string from one UTF-8 char to one UTF-16 char
*
* Normally should be handled by mb_convert_encoding, but
* provides a slower PHP-only method for installations
* that lack the multibye string extension.
*
* @param string $utf8 UTF-8 character
* @return string UTF-16 character
* @access private
*/
function utf82utf16($utf8)
{
// oh please oh please oh please oh please oh please
if(function_exists('mb_convert_encoding')) {
return mb_convert_encoding($utf8, 'UTF-16', 'UTF-8');
}
switch(strlen($utf8)) {
case 1:
// 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 $utf8;
case 2:
// return a UTF-16 character from a 2-byte UTF-8 char
// see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8