Posting data to node via XMLHttpRequest - ajax

Question

I am trying to post data to a form via XMLHttpRequest using the following code:
function submitForm(event) {
event.preventDefault();
var data = new FormData(form);
var request = new XMLHttpRequest();
request.onreadystatechange = function(e) {
var formattedEmails = Object.keys(request.responseText);
formattedEmails.forEach(function(email) {
messages.addMessage(email.to, email.subject, email.message);
});
};
request.open(form.method, form.action);
request.setRequestHeader('content-type', 'application/x-www-form-urlencoded');
request.send(data);
}
When I do this, the data comes in like this
{ '------WebKitFormBoundarywGy70eJqwXdEVot5\r\nContent-Disposition: form-data; name':'"emails"\r\n\r\n Ben,Hernandez,b****#gmail.com\r\n Ann,M*****,a****#gmail.com\r\n \r\n------WebKitFormBoundarywGy70eJqwXdEVot5\r\nContent-Disposition: form-data; name="subject"\r\n\r\nhi {first}!\r\n------WebKitFormBoundarywGy70eJqwXdEVot5\r\nContent-Disposition: form-data; name="message"\r\n\r\nHello {first} {last} {email}\r\n------WebKitFormBoundarywGy70eJqwXdEVot5\r\nContent-Disposition: form-data; name="submit"\r\n\r\nPreview\r\n------WebKitFormBoundarywGy70eJqwXdEVot5--\r\n' }
Which appears to just be a ridiculously long string of data that I need to format somehow?. When I remove the above code and allow the form to just submit like regular to the form.action page. I get this back:
{ emails: 'Ben,Hernandez,b****#gmail.com\r\nAnn,M****,a***#gmail.com\r\n',
subject: 'hi {first}!',
message: 'Hello {first} {last} {email}',
submit: 'Preview' }
Which is definitely what I want. How do I extract that from the ridiculous string above or change my post request so I get something much more manageable.
Should note that backend is express on node.
Thanks!

Answer 1

I ended up abandoning doing the
var data = new FormData(form);
and just manually putting my params string together. If anyone knows how to do this, I am still interested in answers.