Php's json_decode and firefox's javascript compatibility - php

it appears if you have something like
var my_var = {"foo" : "bar"};
in javascript (with firefox at least) and post it to a php server you will receive a string like
{foo:"bar",}
on the server side. But json_decode in php doesn't like the trailing ',' or the lack or quotes around 'foo'. Is there a nice way to clean up the received json string?
The json object is sent with the drupal module json services.
EDIT: This question can be closed. The badly formed json is due to badly written js in the drupal module

What code are you using to POST the data? Make sure you're using something like json2.js.

Related

Remove double-quotes from a json_encoded string on the keys

I have a json_encoded array which is fine.
I need to strip the double-quotes on all of the keys of the json string on returning it from a function call.
How would I go about doing this and returning it successfully?
Thanks!
I do apologise, here is a snippet of the json code:
{"start_date":"2011-01-01 09:00","end_date":"2011-01-01 10:00","text":"test"}
Just to add a little more info:
I will be retrieving the JSON via an AJAX request, so if it would be easier, I am open to ideas in how to do this on the javascript side.
EDITED as per anubhava's comment
$str = '{"start_date":"2011-01-01 09:00","end_date":"2011-01-01 10:00","text":"test"}';
$str = preg_replace('/"([^"]+)"\s*:\s*/', '$1:', $str);
echo $str;
This certainly works for the above string, although there maybe some edge cases that I haven't thought of for which this will not work. Whether this will suit your purposes depends on how static the format of the string and the elements/values it contains will be.
TL;DR: Missing quotes is how Chrome shows it is a JSON object instead of a string. Ensure that you have Header('Content-Type: application/json; charset=UTF8'); in PHP's AJAX response to solve the real problem.
DETAILS:
A common reason for wanting to solve this problem is due to finding this difference while debugging the processing of returned AJAX data.
In my case I saw the difference using Chrome's debugging tools. When connected to the legacy system, upon success, Chrome showed that there were no quotes shown around keys in the response according to the debugger. This allowed the object to be immediately treated as an object without using a JSON.parse() call. Debugging my new AJAX destination, there were quotes shown in the response and variable was a string and not an object.
I finally realized the true issue when I tested the AJAX response externally saw the legacy system actually DID have quotes around the keys. This was not what the Chrome dev tools showed.
The only difference was that on the legacy system there was a header specifying the content type. I added this to the new (WordPress) system and the calls were now fully compatible with the original script and the success function could handle the response as an object without any parsing required. Now I can switch between the legacy and new system without any changes except the destination URL.

printing a PHP string and parsing it as a JSON in javascript

I have a json_string in my database.
I echo and parse it to an object in javascript
I do
$.parseJSON('<?php echo $json_string;?>');
I get a json parse error.
What should I be doing?
This is my json_String
{"patches":[[{"diffs":[[1,"\u000a\u000a printhellon() {\u000a\u000a\u000a}d\u000a\u000a\u000a"]],"start1":0,"start2":0,"length1":0,"length2":26}],[{"diffs":[[0,") {\u000a\u000a\u000a}d"],[1,"s"],[0,"\u000a\u000a\u000a"]],"start1":15,"start2":15,"length1":11,"length2":12}],[{"diffs":[[0," {\u000a\u000a\u000a}ds"],[1,"d"],[0,"\u000a\u000a\u000a"]],"start1":16,"start2":16,"length1":11,"length2":12}]],"times":[1314489779299,1314489779408,1314489779581]}
I think JSON parsers don't like line breaks in strings for some reason. Parsing worked for me after removing the \u000a characters.
Edit: just like Brad said, it would be better to include the code directly as an object. Parsing JSON is usually more useful for data obtained using Ajax or something.
From your example, it appears like you're trying to insert PHP code into your javascript. You can't use PHP like that. PHP is server side, while Javascript runs in the browser after the page has been downloaded.
If you must get data from PHP to your javascript, you need to use AJAX. It's actually really easy with JQuery. Check out http://api.jquery.com/jQuery.ajax/

Clean php output into javascript

Due to the nature of my project. I am pulling data from my db and outputting to javascript. Things were working just fine till I got to the main content. It has strings like (;, :, - ''). How do I ensure that these are displayed without crushing my script coz as for now nothing seems to work.
If all you have is a single string value then see answer by Tomalak Geret'kal.
If there is any chance of getting something more than a single value from your database, like an array, object, null, or anything more complex, then I would suggest using json_encode. By using something like this:
<script>
var your_JavaScript_variable = <?php echo json_encode(your_PHP_variable); ?>;
</script>
you can pass complex data structures, arrays, or even single strings from PHP to JavaScript with all of your backslash escaping done automatically.
Additionally when you use JSON for moving your data from PHP to JavaScript it will be easy to make your application get the data from your server asynchronously without page refreshes using AJAX in the future.
You can use the PHP addslashes function for inserting into Javascript, and htmlspecialchars for inserting into HTML.
You should be encoding that data into json. PHP has a handy function to do this, json_encode.
Be sure to use the JSON_HEX_QUOTE option or the quotes in your data will break your js.
Read this: http://php.net/manual/en/function.json-encode.php

Why doesn't jQuery.parseJSON() work on all servers?

Hey there, I have an Arabic contact script that uses Ajax to retrieve a response from the server after filling the form.
On some apache servers, jQuery.parseJSON() throws an invalid json excepion for the same json it parses perfectly on other servers. This exception is thrown only on chrome and IE.
The json content gets encoded using php's json_encode() function. I tried sending the correct header with the json data and setting the unicode to utf-8, but that didn't help.
This is one of the json responses I try to parse (removed the second part of if because it's long):
{"pageTitle":"\u062e\u0637\u0623 \u0639\u0646\u062f \u0627\u0644\u0625\u0631\u0633\u0627\u0644 !"}
Note: This language of this data is Arabic, that's why it looks like this after being parsed with php's json_encode().
You can try to make a request in the examples given down and look at the full response data using firebug or webkit developer tools. The response passes jsonlint!
Finally, I have two urls using the same version of the script, try to browse them using chrome or IE to see the error in the broken example.
The working example : http://namodg.com/n/
The broken example: http://www.mt-is.co.cc/my/call-me/
Updated: To clarify more, I would like to note that I manged to fix this by using the old eval() to parse the content, I released another version with this fix, it was like this:
// Parse the JSON data
try
{
// Use jquery's default parser
data = $.parseJSON(data);
}
catch(e)
{
/*
* Fix a bug where strange unicode chars in the json data makes the jQuery
* parseJSON() throw an error (only on some servers), by using the old eval() - slower though!
*/
data = eval( "(" + data + ")" );
}
I still want to know if this is a bug in jquery's parseJSON() method, so that I can report it to them.
Found the problem! It was very hard to notice, but I saw something funny about that opening brace... there seemed to be a couple of little dots near it. I used this JavaScript bookmarklet to find out what it was:
javascript:window.location='http://www.google.com/search?q=u+'+('000'+prompt('String?').charCodeAt(prompt('Index?')).toString(16)).slice(-4)
I got the results page. Guess what the problem is! There is an invisible character, repeated twice actually, at the beginning of your output. The zero width non-breaking space is also called the Unicode byte order mark (BOM). It is the reason why jQuery is rejecting your otherwise valid JSON and why pasting the JSON into JSONLint mysteriously works (depending on how you do it).
One way to get this unwanted character into your output is to save your PHP files using Windows Notepad in UTF-8 mode! If this is what you are doing, get another text editor such as Notepad++. Resave all your PHP files without the BOM to fix your problem.
Step 1: Set up Notepad++ to encode files in UTF-8 without BOM by default.
Step 2: Open each existing PHP file, change the Encoding setting, and resave it.
You should try using json2.js (it's on https://github.com/douglascrockford/JSON-js)
Even John Resig (creator of jQuery) says you should:
This version of JSON.js is highly recommended. If you're still using the old version, please please upgrade (this one, undoubtedly, cause less issues than the previous one).
http://ejohn.org/blog/the-state-of-json/
I don't see anything related to parseJSON()
The only difference I see is that in the working example a session-cookie is set(guess it is needed for the "captcha", the mathematical calculation), in the other example no session-cookie is set. So maybe the comparision of the calculation-result fails without the session-cookie.

What JSON does this CF code return?

Trying to implement the excellent jQuery bidirectional infite scroll as explained here:
http://www.bennadel.com/blog/1803-Creating-A-Bidirectional-Infinite-Scroll-Page-With-jQuery-And-ColdFusion.htm
For the server-side, which returns JSON, the example is in ColdFusion. Trying to implement it in PHP.
I need to find out what the format of the JSON is.
RIght now, I am returning
[{"src":"https:\/\/s3.amazonaws.com\/gbblr_2\/100\/IMG_1400 - original.jpg","offset":"5"},{"src":"https:\/\/s3.amazonaws.com\/gbblr_2\/100\/IMG_1399 - original.jpg","offset":6},{"src":"https:\/\/s3.amazonaws.com\/gbblr_2\/100\/IMG_1398 - original.jpg","offset":7}]
which doesn't work, in the html that is generated it shows "UNDEFINED" for both the src and the offset variables.
So my question: what kind of JSON does that coldfusion code generate? What is the format of JSON that I need to return.
Thanks for any tips!!
CF's JSON mentioned in Ben's post is similar to this:
[{"SRC":"http:\/\/example.com\/public","OFFSET":3.0},{"SRC":"http:\/\/example.com\/public","OFFSET":3.0}]
I'd try to check key names first. Yes, CF makes them uppercase, and JS doesn't like it sometimes. Check his function applyListItems() and check if RegExp finds something or not.
If this doesn't help little Firebug line debugging and console.log will do the trick I guess.
Looks like the JSON you're creating should be equivalent to his. He is creating an array of structures; where each structure contains the keys "src" and "offset".
He is converting to base64 and binary for streaming purposes, but I don't know how that would work -- or if it would be required -- for a php implementation.
I would use Firebug to figure out exactly where in your JavaScript the error is being thrown. That will tell you more about what exactly the problem is.

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