To JSON and json_decode in PHP and JavaScript

Question

I'm trying to pass a JavaScript object to a PHP script through jquery.ajax(), basically:

var bigArray = new Object();
//Dode
//Start loop
bigArray[x] = {name: exname, id: exID, order:e, set: setBox, inc: incBox, example: exampleBox, day: i};

So it's pretty much an array of these objects.

    var anotherTest = $.toJSON(bigArray);
    var ajxFile = "routineajax.php";
    $.ajax({
        type: 'POST',
        processData: false,
        url: ajxFile,
        data: anotherTest,
        success: function(data) {
            $('#result').html(data);
            alert('Load was performed.');
        }
    });
});

The PHP side script

 print_r($_POST);
 $params = json_decode($_POST);
 print_r($params)

The Ajax call is going through, and I can see in Firebug, but print_r($_POST) is returning an empty array. While if I change it to $_GET in both the $.ajax function and PHP script it works. My main problem is I'm getting this error message:

Warning: json_decode() expects parameter 1 to be string, array given in

How do I fix this problem?

---

After adding this snippet to the PHP file

  $data = file_get_contents('php://input');
  var_dump($data);
  var_dump(json_decode($data));

I'm getting this output

string'{"0"{"name":"Decline`Abs","id":"54","order":0,"set":"","inc":"","example":"","day":1}}' (length=87)`
  object(stdClass)[2]
      public '0' =>
        object(stdClass)[4]
          public 'name' => string 'Decline Abs' (length=11)
          public 'id' => string '54' (length=2)
          public 'order' => int 0
          public 'set' => string '' (length=0)
          public 'inc' => string '' (length=0)
          public 'example' => string '' (length=0)
          public 'day' => int 1

So at least it's going through, I'm not sure how to access it though, a step in the right direction!

Solution

I think the problem is that normally POST data is sent encoded as key=value&key2=value2, and you're sending it as JSON. Try accessing the raw post data as follows:

$data = file_get_contents('php://input');
var_dump($data);
var_dump(json_decode($data));

and see if that works. If not, please post in your question what it returns, if anything.

---

Based on the comment below and additions to the OP.

Did the var_dump of $data copy-paste correctly? The reason I ask is that this: string'{"0"{"name" does not look right to me. That isn't valid JSON or a properly encoded POST string. It might be that some of the characters got encoded when you copied and pasted.

Either way, you're now getting the result you need. The stdClass is just a blank container that it puts the data into, which you can access using the normal object syntax. In this case, you'd have to do $data->{0}->name I think, because of that 0. If you do $data = json_decode($data, true) it will be an associative array, and you can access the POST'ed data as $data[0]['name'].

If you want to keep exploring this, it might be helpful to show the results of doing window.console.dir(data) right before you do the ajax request, and make sure when you var_dump(data), you view the source of the page to copy and paste. window.console.dir(data) will show data's properties in the Firebug window (you are using Firebug, right?). It also works in Chrome's debugger, and maybe others as well. Like I said though, it looks like you're probably getting what you need already, so investigating isn't necessary.