Handling malformed JSON in PHP - php

Question

I'm trying to write a php script that handles data from a webservice that delivers "json" as a string. The problem is the string isn't really json; it's javascript. Specifically, the keys are not quoted, although the variables are. Example (the actual data is much longer and more complicated):
{desc:'User defined payload'}
As described by the php manual, json_decode() correctly fails to interpret this string.
My question is, how can I successfully interpret a string like this in php?
The only solution I can think of is to write some regular expressions that fix the syntax, but then I'd have two problems.
EDIT
Hadvig's suggestion of using the Services_JSON pear module worked, and looks like a general solution. Once I had the module installed, my code looked like this:
require_once 'PEAR.php';
require_once 'Services/JSON.php';
$Services_JSON = new Services_JSON();
$data = $Services_JSON->decode($malformed_json);
Unfortunately, this is SLOW. To interpret the whole string (~400,000 chars) took > 36 seconds! Using a regular expression to fix the quotes and then using json_decode took ~0.04 seconds. Here's what I used:
// fix single quotes
$s = str_replace("'", '"', $malformed_json);
// fix unquoted keys
$valid_json = preg_replace('/([{\[,])\s*([a-zA-Z0-9_]+?):/', '$1"$2":', $s);
$data = json_decode($valid_json);
Of course, this will break if the data contains any quotes, brackets, or commas.

Answer 1

Ok. try to use this. http://pear.php.net/pepr/pepr-proposal-show.php?id=198 I just check your string

Answer 2

Depends on how complicated your data is :
$output = "{desc:'User defined payload',asc:'whatever'}";
function json_js_php($string){
$string = str_replace("{",'{"',$string);
$string = str_replace(":'",'":"',$string);
$string = str_replace("',",'","',$string);
$string = str_replace("'}",'"}',$string);
return $string;
}
echo json_decode(json_js_php($output))->{'desc'};
returns : User defined payload

Answer 3

Using regexp is a no-go. JSON grammar cannot be correctly parsed using regexp. You will open yourself to a ton of future bugs.
I recommend using some kind of a YAML parser. YAML is backwards-compatible with JSON and allows unquoted literals at the same time.
Symfony YAML component worked great for me.
And remember that there will be a performance penalty in comparison to json_decode because it's implemented natively.

Answer 4

If the problem is just the unquoted identifiers and the data can be assumed not to contain any curly brackets, this should do it:
$goodJson = preg_replace("/{\s*([a-zA-Z0-9_]+)/", '{ "$1"', $badJson);
(not tested!)

Answer 5

Try this:
$jsonString = "{result:true,username:'usr000242',password:'123456',message:'Cannot send username and password to email#test.com'}";
function manualFixInvalidJSON($jsonString=''){
$jsonString = preg_replace("/([{,])([a-zA-Z][^: ]+):/", "\$1\"$2\":", $jsonString);
$jsonString = preg_replace("/:([a-zA-Z\'][^:]+)([,}])/", ":\"$1\"$2", $jsonString);
$jsonString = json_decode($jsonString,true);
function trimer($val){
return trim(trim($val,"'"),"\"");
}
$jsonString = array_map('trimer', $jsonString);
return json_encode($jsonString);
}
echo jsonString($jsonString);