Syntax Error{} AJAX success cannot read JSON returned from PHP

Question

I need some help here. I'm sending simple request to server, and the return I expected is JSON as data type. But when I checked in development tools console log I get "parsererror SyntaxError {}" and "parsererror".

How can I make this right? Below is the code.

JQuery

$(':submit').live('click', function() {

    $.ajax({

            type : 'post',        
            url: 'testJSON.php',
            beforeSend:console.log('sending...'),
            dataType: 'json',
            contentType: "application/json; charset=utf-8",
            success: function(data){

                console.log(data.status);
                // do magic
                },

            error: function(XMLHttpRequest, textStatus, errorThrown) {

                console.log(textStatus, errorThrown);

                },

            complete: function(XMLHttpRequest, status) {

                console.log(status);

                }

        });

    return false;
    });

and this is the testJSON.php

<?php

$data = array(

    "status" => 1,
    "firstname" => "foo",
    "lastname" => "bar",

);

header('Content-type: application/json; charset=utf-8" ');
echo json_encode($data);


exit();

?>

FYI I use the latest version of WAMP. Any help very much appreciated.

Please note that you have invalid JSON and you've posted everything except the JSON ;-) — Álvaro González
– Álvaro González, Commented Apr 29, 2013 at 11:03
@ÁlvaroG.Vicario I'm not sure what you mean by invalid JSON... if you mean why I sending request to server without JSON, simply because the data that needed to run the php script stored in $_SESSION[] — ani
– ani, Commented Apr 29, 2013 at 14:28
You said that you were getting parsererror when parsing JSON... Sorry if I misunderstood. — Álvaro González
– Álvaro González, Commented Apr 29, 2013 at 15:05
It's true. I try to preview the testJSON.php, then Copy text from the browser and paste it inside online JSON validator (jsonlint.com) and I get a Valid JSON... still don't know why the JS can't read it as JSON. — ani
– ani, Commented Apr 29, 2013 at 15:31
Do you save testJSON.php as UTF-8 with BOM or without BOM? — Álvaro González
– Álvaro González, Commented Apr 29, 2013 at 15:32

chandresh_cool · Accepted Answer · 2013-04-29 10:55:45Z

1

Set the header of the content to type of json... Here is an example of setting header type.

header('Cache-Control: no-cache, must-revalidate');
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
header('Content-type: application/json');

In jQuery 1.4 onwards the JSON data is parsed in a strict manner.

Any malformed JSON is rejected and a parse error is thrown.

answered Apr 29, 2013 at 10:55

chandresh_cool

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1 Comment

ani Over a year ago

I'm using jQuery 1.8.3. I try this solution but the code still not working. I run the preview of the php script the data successfully converted into JSON type, I don't understand why AJAX can't receive it, any idea?

Yogesh Suthar · Accepted Answer · 2013-04-29 10:59:58Z

0

remove " from here

header('Content-type: application/json; charset=utf-8" ');

should be

header('Content-type: application/json; charset=utf-8');

edited Apr 29, 2013 at 10:59

answered Apr 29, 2013 at 10:54

Yogesh Suthar

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3 Comments

Richard de Wit Over a year ago

By setting dataType: 'json' the data is already (attemptedly) parsed

Yogesh Suthar Over a year ago

@GeenHenk Yeah I noticed that, thanks for correcting the mistake...:)

ani Over a year ago

@GeenHenk I already removed it, but still get parsererror SyntaxError{} in my log ...

maddob · Accepted Answer · 2013-04-29 11:13:22Z

0

I tried your code and I got an error at the beforeSend parameter. The statements shall be encapsulated in a function:

...    
beforeSend: function() {console.log('sending...')},
...

After that everything worked. Maybe it also depends on the jQuery version. Which one did you use? I tried with versions 1.8.1 and upwards

answered Apr 29, 2013 at 11:13

maddob

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1 Comment

ani Over a year ago

I'm using V 1.8.3. and the code work for me.. the reason iI use this parameter so that I know the AJAX works for the first place (and by the way the code is ... beforeSend:console.log('sending...')... without function(){})

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