CORS request not working

[Anonymous]

I'm currently trying to retrieve and send data from Marketo's API. The problem is : my web platform is Salesforce Community. If I understand correctly this web tool, I'm not allowed to use anything else than pure javascript.

I've built a CORS request like this :

function createCORSRequest(method, url) {
  var xhr = new XMLHttpRequest();
  if ("withCredentials" in xhr) {
    xhr.open(method, url, true);
  } else if (typeof XDomainRequest != "undefined") {
    xhr = new XDomainRequest();
    xhr.open(method, url);
  } else {
    xhr = null;
  }
  return xhr;
}
function makeCorsRequest() {
  var url = document.getElementById('url').value;
  var xhr = createCORSRequest('GET', url);
  if (!xhr) {
    alert('CORS not supported');
    return;
  }
  xhr.onload = function() {
    var text = xhr.responseText;
    alert('Response from CORS request to ' + url + 'is : ' + text);
  };
  xhr.onerror = function() {
    alert('Woops, there was an error making the request.');
  };
  xhr.send();
}

With the help of http://www.html5rocks.com/en/tutorials/cors/, but the server doesn't seem to accept the request since this error comes back :

"No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://testurl…' is therefore not allowed access."

Does anyone know if Marketo's API accepts CORS requests? Or maybe have an idea that would help me solve this? Thank you very much.

[SanfordWhiteman]

The REST API should never be used by directly customer-facing applications.  It's intended to be used in server-to-server contexts, preferably using bulk operations.  If you explain in full what you are actually trying to accomplish, as Kenny said, we can give you some pointers.

[Kenny_Elkington]

I responded over on StackOverflow: Call Marketo API using javascript only - Stack Overflow​  There are probably other options depending on what exactly you're trying to accomplish.