json.php

zapatec suite 最新版 20070204,非常棒的ajax widgets 工具包

<?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 <[e-mail]>
 * @author      Matt Knapp <mdknapp[at]gmail[dot]com>
 * @author      Brett Stimmerman <brettstimmerman[at]gmail[dot]com>
 * @copyright   2005 Michal Migurski
 * @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 $ut8;

            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
                return chr(0x07 & (ord($utf8{0}) >> 2))
                     . chr((0xC0 & (ord($utf8{0}) << 6))
                         | (0x3F & ord($utf8{1})));
                
            case 3:
                // return a UTF-16 character from a 3-byte UTF-8 char
                // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                return chr((0xF0 & (ord($utf8{0}) << 4))
                         | (0x0F & (ord($utf8{1}) >> 2)))
                     . chr((0xC0 & (ord($utf8{1}) << 6))
                         | (0x7F & ord($utf8{2})));
        }

        // ignoring UTF-32 for now, sorry
        return '';
    }        

   /**
    * encodes an arbitrary variable into JSON format
    *
    * @param    mixed   $var    any number, boolean, string, array, or object to be encoded.
    *                           see argument 1 to Services_JSON() above for array-parsing behavior.
    *                           if var is a strng, note that encode() always expects it
    *                           to be in ASCII or UTF-8 format!
    *
    * @return   mixed   JSON string representation of input var or an error if a problem occurs
    * @access   public
    */
    function encode($var)
    {
        switch (gettype($var)) {
            case 'boolean':
                return $var ? 'true' : 'false';
            
            case 'NULL':
                return 'null';
            
            case 'integer':
                return (int) $var;
                
            case 'double':
            case 'float':
                return (float) $var;
                
            case 'string':
                // STRINGS ARE EXPECTED TO BE IN ASCII OR UTF-8 FORMAT
                $ascii = '';
                $strlen_var = strlen($var);

               /*
                * Iterate over every character in the string,
                * escaping with a slash or encoding to UTF-8 where necessary
                */
                for ($c = 0; $c < $strlen_var; ++$c) {
                    
                    $ord_var_c = ord($var{$c});
                    
                    switch (true) {
                        case $ord_var_c == 0x08: