/**
* encodes an arbitrary variable into JSON format
*
* @param mixed $var any number, boolean, string, array, or object to be encoded.
* see argument 1 to JSON() above for array-parsing behavior.
* if var is a strng, note that encode() always expects it
* to be in ASCII or UTF-8 format!
*
* @return string JSON string representation of input var
* @access public
*/
function encode($var)
{
switch (gettype($var)) {
case 'boolean':
return $var ? 'true' : 'false';
case 'NULL':
return 'null';
case 'integer':
return sprintf('%d', $var);
case 'double':
case 'float':
return sprintf('%f', $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[$c]);
switch ($ord_var_c) {
case 0x8:
$ascii .= '\\b';
break;
case 0x9:
$ascii .= '\\t';
break;
case 0xa:
$ascii .= '\\n';
break;
case 0xc:
$ascii .= '\\f';
break;
case 0xd:
$ascii .= '\\r';
break;
case 0x22:
case 0x2f:
case 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 = mb_convert_encoding($char, 'UTF-16', 'UTF-8');
$utf16 = utf8_to_utf16be($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 = mb_convert_encoding($char, 'UTF-16', 'UTF-8');
$utf16 = utf8_to_utf16be($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 = mb_convert_encoding($char, 'UTF-16', 'UTF-8');
$utf16 = utf8_to_utf16be($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 = mb_convert_encoding($char, 'UTF-16', 'UTF-8');
$utf16 = utf8_to_utf16be($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 = mb_convert_encoding($char, 'UTF-16', 'UTF-8');
$utf16 = utf8_to_utf16be($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, count($var) - 1)) {
return sprintf('{%s}', join(',', array_map(array($this, 'name_value'), array_keys($var), array_values($var))));
}
// treat it like a regular array
return sprintf('[%s]', join(',', array_map(array($this, 'encode'), $var)));
case 'object':
$vars = get_object_vars($var);
return sprintf('{%s}', join(',', array_map(array($this, 'name_value'), array_keys($vars), array_values($vars))));
default:
return '';
}
}
/**
* Convert from UTF-8 to UTF-16BE
*/
function test_to16be()
{
$this->assertEqual(utf8_to_utf16be($this->utf8), $this->utf16);
}
