Question

Currently working for the first time with JSON and with little experience of jQuery.
I have this function that gets triggered on “success” of $.ajax request:

function(data) {

    $.each(data.notifications, function(notifications) {
        alert('New Notification!');
    });

}

However I get an error in the firebug console stating “object is undefined” “length = object.length”.

The JSON response is:

["notifications",[["test would like to connect with you",{"Accept":"\/events\/index.php\/user\/connection?userId=20625101&action=accept","Decline":"\/events\/index.php\/user\/connection?userId=20625101&action=decline"}]]]

I guess it has something to do with the number of []s but the JSON was encoded by PHP using json_encode()

Any help would be appreciated!

Thanks 🙂

Answer 1

What you have is a JSON Array. I’m guessing you were looking for something like this:

{
    "notifications": [
        ["test would like to connect with you",
        {
            "Accept": "\/events\/index.php\/user\/connection?userId=20625101&action=accept",
            "Decline": "\/events\/index.php\/user\/connection?userId=20625101&action=decline"
        }]
    ]
}

Although I think a better structure would be:

{
    "notifications": [
        {
            "message": "test would like to connect with you",
            "Accept": "\/events\/index.php\/user\/connection?userId=20625101&action=accept",
            "Decline": "\/events\/index.php\/user\/connection?userId=20625101&action=decline"
        }
    ]
}

This way notification becomes a property of the object, which means you can access it via data.notifications. Otherwise you’d have to access the notifications via data[1] (data[0] would contain the string “notifications” which essentially becomes meaningless).

The following example should give you an idea as far as setting up your data in PHP:

<?php
  $array = array(
      "notifications" => array(
          array(
              "message" => "Test would like to connect with you",
              "Accept" => "/events/index.php/user/connection?userId=20625101&action=accept",
              "Decline" => "/events/index.php/user/connection?userId=20625101&action=decline"
          )
      )
  );

  echo json_encode($array);
?>