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JavaScript AJAX Basics (retiring) AJAX Concepts Finish the AJAX Request

Posted by Stephen Santiago
Stephen Santiago
9,631 Points

AJAX callback function - Trying to add code to open request.

I am not sure if this is a syntax error, it seams like everything is in place but the code challenge will not let me proceed. Had an issue with the workspace in this section as well, not sure if they are related.

app.js 
var request = new XMLHttpRequest();
request.onreadystatechange = function () {
  if (request.readyState === 4) {
    document.getElementById("footer").innerHTML = request.responseText;
    request.open("GET","footer.html");
  }
};
index.html 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>AJAX with JavaScript</title>
  <script src="app.js"></script>
</head>
<body>
  <div id="main">
    <h1>AJAX!</h1>
  </div>
  <div id="footer"></div>
</body>
</html>

1 Answer

Kristian Terziev
Kristian Terziev
28,449 Points

Hello Stephen,

request.onreadystatechange is a callback and it will be executed when you have completed the request. But the request can't be completed because you open it inside the callback. You have to open the request outside the callback. Like so:

var request = new XMLHttpRequest();
request.onreadystatechange = function () {
  if (request.readyState === 4) {
    document.getElementById("footer").innerHTML = request.responseText;
  }
};
request.open("GET","footer.html");
Stephen Santiago
Stephen Santiago
9,631 Points

Thank you Kristian, that worked perfectly.