Is it possible to get page redirect information via Ajax?

Question

Without ajax, if we load http://example.com/1 and if it redirects to http://example.com/2 then the browser gets appropriate headers and the Browser URL

Answer 1

As the already mentioned responseURL doesn't have the best browser support yet, there are 2 more alternative for this case that could be used, http request headers and cookies.

The benefit with these is they don't interfere with the content itself, like for example query string keys, hash tags or embedded in the response data.

---

Request headers

Server side

• PHP

  $req->addHeader("X-Response-Url", "....");
  

• ASP

  headers.Add("X-Response-Url", "....");
  

Client side

xhr.onreadystatechange = function(e) {
  if (xhr.status == 200 && xhr.readyState == 4) {

    var resp_url = xhr.getResponseHeader("X-Response-Url");

    if (send_url != resp_url) {
      // redirected
    }

  }
}

---

Cookies

• PHP

  setcookie("XResponseUrl", "...");
  

• ASP

  Response.Cookies("XResponseUrl") = "..."
  

Client side

xhr.onreadystatechange = function(e) {
  if (xhr.status == 200 && xhr.readyState == 4) {

    var resp_url = getCookie("XResponseUrl");

    if (send_url != resp_url) {
      // redirected
    }

  }
}


function getCookie(name) {
  var re = new RegExp(name + "=([^;]+)");
  var value = re.exec(document.cookie);
  return (value != null) ? unescape(value[1]) : null;
}