json.php.svn-base

php的通用框架

<?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
 * @version     CVS: $Id$
 * @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
				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:
							$ascii .= '\b';
							break;
						case $ord_var_c == 0x09:
							$ascii .= '\t';
							break;
						case $ord_var_c == 0x0A:
							$ascii .= '\n';
							break;
						case $ord_var_c == 0x0C:
							$ascii .= '\f';
							break;
						case $ord_var_c == 0x0D:
							$ascii .= '\r';
							break;

						case $ord_var_c == 0x22:
						case $ord_var_c == 0x2F:
						case $ord_var_c == 0x5C:
							// double quote, slash, slosh
							$ascii .= '\\'.$var{$c};
							break;

						case (($ord_var_c >= 0x20) && ($ord_var_c <= 0x7F)):
							// characters U-00000000 - U-0000007F (same as ASCII)
							$ascii .= $var{$c};
							break;

						case (($ord_var_c & 0xE0) == 0xC0):
							// characters U-00000080 - U-000007FF, mask 110XXXXX
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c, ord($var{$c + 1}));
							$c += 1;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;

						case (($ord_var_c & 0xF0) == 0xE0):
							// characters U-00000800 - U-0000FFFF, mask 1110XXXX
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c,
										 ord($var{$c + 1}),
										 ord($var{$c + 2}));
							$c += 2;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;

						case (($ord_var_c & 0xF8) == 0xF0):
							// characters U-00010000 - U-001FFFFF, mask 11110XXX
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c,
										 ord($var{$c + 1}),
										 ord($var{$c + 2}),
										 ord($var{$c + 3}));
							$c += 3;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;

						case (($ord_var_c & 0xFC) == 0xF8):
							// characters U-00200000 - U-03FFFFFF, mask 111110XX
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c,
										 ord($var{$c + 1}),
										 ord($var{$c + 2}),
										 ord($var{$c + 3}),
										 ord($var{$c + 4}));
							$c += 4;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;

						case (($ord_var_c & 0xFE) == 0xFC):
							// characters U-04000000 - U-7FFFFFFF, mask 1111110X
							// see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
							$char = pack('C*', $ord_var_c,
										 ord($var{$c + 1}),
										 ord($var{$c + 2}),
										 ord($var{$c + 3}),
										 ord($var{$c + 4}),
										 ord($var{$c + 5}));
							$c += 5;
							$utf16 = $this->utf82utf16($char);
							$ascii .= sprintf('\u%04s', bin2hex($utf16));
							break;
					}
				}

				return '"'.$ascii.'"';

			case 'array':
			   /*
				* As per JSON spec if any array key is not an integer
				* we must treat the the whole array as an object. We
				* also try to catch a sparsely populated associative
				* array with numeric keys here because some JS engines
				* will create an array with empty indexes up to
				* max_index which can cause memory issues and because
				* the keys, which may be relevant, will be remapped
				* otherwise.
				*
				* As per the ECMA and JSON specification an object may
				* have any string as a property. Unfortunately due to
				* a hole in the ECMA specification if the key is a
				* ECMA reserved word or starts with a digit the
				* parameter is only accessible using ECMAScript's
				* bracket notation.
				*/

				// treat as a JSON object
				if (is_array($var) && count($var) && (array_keys($var) !== range(0, sizeof($var) - 1))) {
					$properties = array_map(array($this, 'name_value'),
											array_keys($var),
											array_values($var));

					foreach($properties as $property) {
						if(Services_JSON::isError($property)) {
							return $property;
						}
					}

					return '{' . join(',', $properties) . '}';
				}

				// treat it like a regular array
				$elements = array_map(array($this, 'encode'), $var);

				foreach($elements as $element) {
					if(Services_JSON::isError($element)) {
						return $element;
					}
				}

				return '[' . join(',', $elements) . ']';

			case 'object':