note 100835 modified in function.json-encode by danbrown
| From: | danbrown@php.net | Date: | Wed, 08 Dec 2010 16:04:04 +0000 |
| Subject: | note 100835 modified in function.json-encode by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-174709@lists.php.net to get a copy of this message | ||
For users of php 5.1.6 or lower, a native json_encode function. This version handles objects, and
makes proper distinction between [lists] and {associative arrays}, mixed arrays work as well. It can
handle newlines and quotes in both keys and data.
This function will convert non-ascii symbols to "\uXXXX" format as does json_encode.
Besides that, it outputs exactly the same string as json_encode. Including UTF-8 encoded 2-, 3- and
4-byte characters. It is a bit faster than PEAR/JSON::encode, but still slow compared to php
5.3's json_encode. It encodes any variable type exactly as the original.
Relative speeds:
PHP json_encode: 1x
__json_encode: 31x
PEAR/JSON: 46x
NOTE: I assume the input will be valid UTF-8. I don't know what happens if your data contains
illegal Unicode sequences. I tried to make the code fast and compact.
<?php
function __json_encode( $data ) {
if( is_array($data) || is_object($data) ) {
$islist = is_array($data) && ( empty($data) || array_keys($data) ===
range(0,count($data)-1) );
if( $islist ) {
$json = '[' . implode(',', array_map('__json_encode', $data) ) .
']';
} else {
$items = Array();
foreach( $data as $key => $value ) {
$items[] = __json_encode("$key") . ':' . __json_encode($value);
}
$json = '{' . implode(',', $items) . '}';
}
} elseif( is_string($data) ) {
# Escape non-printable or Non-ASCII characters.
# I also put the \\ character first, as suggested in comments on the 'addclashes' page.
$string = '"' . addcslashes($data, "\\\"\n\r\t/" . chr(8) . chr(12))
. '"';
$json = '';
$len = strlen($string);
# Convert UTF-8 to Hexadecimal Codepoints.
for( $i = 0; $i < $len; $i++ ) {
$char = $string[$i];
$c1 = ord($char);
# Single byte;
if( $c1 <128 ) {
$json .= ($c1 > 31) ? $char : sprintf("\\u%04x", $c1);
continue;
}
# Double byte
$c2 = ord($string[++$i]);
if ( ($c1 & 32) === 0 ) {
$json .= sprintf("\\u%04x", ($c1 - 192) * 64 + $c2 - 128);
continue;
}
# Triple
$c3 = ord($string[++$i]);
if( ($c1 & 16) === 0 ) {
$json .= sprintf("\\u%04x", (($c1 - 224) <<12) + (($c2 - 128) << 6) + ($c3
- 128));
continue;
}
# Quadruple
$c4 = ord($string[++$i]);
if( ($c1 & 8 ) === 0 ) {
$u = (($c1 & 15) << 2) + (($c2>>4) & 3) - 1;
$w1 = (54<<10) + ($u<<6) + (($c2 & 15) << 2) + (($c3>>4) & 3);
$w2 = (55<<10) + (($c3 & 15)<<6) + ($c4-128);
$json .= sprintf("\\u%04x\\u%04x", $w1, $w2);
}
}
} else {
# int, floats, bools, null
$json = strtolower(var_export( $data, true ));
}
return $json;
}
?>
[EDIT BY danbrown AT php DOT net: Contains a bugfix by the original poster on 08-DEC-2010 with the
following message: "I discovered a rather bad bug in my __json_encode function below. On
versions prior to php 5.2.5, all 'f' characters are escaped to '\f'. This is
because addcslashes in php < 5.2 doesn't understand \f as 'formfeed'."]
--was--
For users of php 5.1.6 or lower, a native json_encode function. This version handles objects, and
makes proper distinction between [lists] and {associative arrays}, mixed arrays work as well. It can
handle newlines and quotes in both keys and data.
This function will convert non-ascii symbols to "\uXXXX" format as does json_encode.
Besides that, it outputs exactly the same string as json_encode. Including UTF-8 encoded 2-, 3- and
4-byte characters. It is a bit faster than PEAR/JSON::encode, but still slow compared to php
5.3's json_encode. It encodes any variable type exactly as the original.
Relative speeds:
PHP json_encode: 1x
__json_encode: 31x
PEAR/JSON: 46x
NOTE: I assume the input will be valid UTF-8. I don't know what happens if your data contains
illegal Unicode sequences. I tried to make the code fast and compact.
<?php
function __json_encode( $data ) {
if( is_array($data) || is_object($data) ) {
$islist = is_array($data) && ( empty($data) || array_keys($data) ===
range(0,count($data)-1) );
if( $islist ) {
$json = '[' . implode(',', array_map('__json_encode', $data) ) .
']';
} else {
$items = Array();
foreach( $data as $key => $value ) {
$items[] = __json_encode("$key") . ':' . __json_encode($value);
}
$json = '{' . implode(',', $items) . '}';
}
} elseif( is_string($data) ) {
# Escape non-printable or Non-ASCII characters.
$string = '"' . addcslashes($data, "\"\\\n\r\t\f/" . chr(8)) .
'"';
$json = '';
$len = strlen($string);
# Convert UTF-8 to Hexadecimal Codepoints.
for( $i = 0; $i < $len; $i++ ) {
$char = $string[$i];
$c1 = ord($char);
# Single byte;
if( $c1 <128 ) {
$json .= ($c1 > 31) ? $char : sprintf("\\u%04x", $c1);
continue;
}
# Double byte
$c2 = ord($string[++$i]);
if ( ($c1 & 32) === 0 ) {
$json .= sprintf("\\u%04x", ($c1 - 192) * 64 + $c2 - 128);
continue;
}
# Triple
$c3 = ord($string[++$i]);
if( ($c1 & 16) === 0 ) {
$json .= sprintf("\\u%04x", (($c1 - 224) <<12) + (($c2 - 128) << 6) + ($c3
- 128));
continue;
}
# Quadruple
$c4 = ord($string[++$i]);
if( ($c1 & 8 ) === 0 ) {
$u = (($c1 & 15) << 2) + (($c2>>4) & 3) - 1;
$w1 = (54<<10) + ($u<<6) + (($c2 & 15) << 2) + (($c3>>4) & 3);
$w2 = (55<<10) + (($c3 & 15)<<6) + ($c4-128);
$json .= sprintf("\\u%04x\\u%04x", $w1, $w2);
}
}
} else {
# int, floats, bools, null
$json = strtolower(var_export( $data, true ));
}
return $json;
}
?>
http://php.net/manual/en/function.json-encode.php