Question

My AJAX request to pings the server, and the URL but returns an error because it doesnt like the ‘<‘ as the open tag for the php script.

AJAX script.

 $.ajax({
url: "data.php",
type: "POST",
data: JSON.stringify({"data":transaction}),
dataType: "json",
success: function(data, textStatus, jqXHR){
    alert("success");
    currentProcesses -= 1;
    $("<span>").html("Ajax Call Complete.  Releasing lock for process").appendTo($(body));
},
error: function(jqXHR, textStatus, errorThrown){
    alert("error with ajax call "+textStatus+" "+errorThrown);
}
 });

php script

 <?php
   $win = $_POST['data'];
 ?>

Am I using the wrong flag settings for the AJAX call?

Answer 1

The body of your POST request is encoded as application/json instead of application/x-www-form-urlencoded.

You aren’t doing anything to make the request say that the data is encoded in JSON and you aren’t doing anything in PHP to try to parse JSON.

As a result, PHP fails to populate $_POST, because the data is in the wrong format.

The solution is: Don’t send JSON. Just give the data property an object as its value, and jQuery will serialise it to application/x-www-form-urlencoded data for you.

data:  { "data": transaction },

(Assuming that transaction is not a complex data type (like an array or object).

Additionally, the body variable is undefined. You should either use a string (to make it a selector: "body") or pass the body element directly: document.body.