JSONP Ajax Error Jquery(Number String) Not Called - php

Question

Since moving my site to https, the mailchimp api no longer works with the standard json ajax calls. These calls now render a same origin policy error. I don't know why this is the case though, because I'm calling a url on my own server. After some investigating, I've surmised that JSONP is my only option. The following script posts correctly to mailchimp but Im unable to get a successful response.
$.ajax({
type:"GET",
url:"https://mysite/book_subscription_process.php?jsonp=?",
data:{fname: $('#fNBookId').val(), lname: $('#lNBookId').val(), email: $('#eBookId').val()},//only input
dataType: "jsonp",
cache: false,
async: false,
jsonp: false,
success: function(data){
console.log('success');
if(data.message == 'failure')
{
alert('Error','There was an error processing your subscription. Please try again.');
}else if(data.message == 'success')
{
alert('success');
}else{
console.log(data.message);
}
},
error: function (xhr, ajaxOptions, thrownError, data) {
// console.log(data.message);
console.log('failure');
alert(xhr.status);
alert(thrownError);
}
});
Server side:
<?php
header("content-type: text/javascript");
if(isset($_GET['jsonp']))
{
$obj->fname = $_GET['fname'];
$obj->lname = $_GET['lname'];
$obj->email = $_GET['email'];
$obj->success = 'success';
$obj->failure = 'failure';
}
header("Content-type: application/json");
$MailChimp = new \Drewm\MailChimp($api_key);
$book = array('id' => $group_id, 'groups' => array('Book'));
$merge_vars = array('FNAME'=> $obj->fname,
'LNAME'=>$obj->lname,
'GROUPINGS'=>array($book)
);
$result = $MailChimp->call('lists/subscribe', array(
'id' => $list_id,
'email' => array('email'=>$obj->email),
'merge_vars' => $merge_vars,
'double_optin' => false,
'update_existing' => true,
'replace_interests' => false,
'send_welcome' => false,
));
if ( ! empty( $result['leid'] ) ) {
echo json_encode($obj->success);
}
else{
echo json_encode($obj->failure);
}
?>
As I said above the info is correctly posted to mailchimp. Each time however, the ajax call errors. I get a 200 OK but get a Jquery[bunch of numbers] not called. The json_encode success statement is executed on the server. Is there a special way that I'm supposed to handle the server side response? Or am I supposed to do something differently on the client side? Thanks in advance.

Answer 1

Same Origin means that the page making the request and the destination server need to have identical protocol, server, and port. For this particular situation, MailChimp isn't either of those -- the page making the request is your HTML page and the server is https://mysite/book_subscription_process.php.
Since you said this corresponds to your move to HTTPS, my guess is that you've moved one end but not the other. Since the code above looks like the front-end page is calling https://mysite, I'd triple check to make sure that the HTML and all scripts are also being served from https://mysite.
I don't think you should need JSONP in this scenario -- it sounds like you are attempting to work from the same origin, you just need to be sure you're doing that properly.