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JavaScript

Posted by Douglas Watts
Douglas Watts
5,464 Points

No Popup

in this code when i run it in Workspace, it's supposed to create an alert.....because the 'missing.html' page doesn't exist:

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <link href='http://fonts.googleapis.com/css?family=varela+round' rel='stylesheet' type='text/css'>
    <link rel="stytlesheet" href="css/main.css">
    <title>AJAX with Javascript</title>
    <script>
      var xhr = new XMLHttpRequest();
      xhr.onreadystatechange = function() {
        if(xhr.readyState === 4) {
          if(xhr.status === 200) {
            document.getElementById('ajax').innerHTML = xhr.responseText;
          } else { 
            alert(xhr.statusText);
          }
         } 

        };

      xhr.open('GET','missing.html');
      function sendAJAX() {
        xhr.send();
        document.getElementById('load').style.display = "none";
      }

    </script>
  </head>
  <body>
    <div class="grid-container centered">
      <div class="grid-100">
        <div class="contained">
          <div class="grid-100">
            <div class="heading">
              <h1>Bring on the AJAX</h1>
              <button id="load" onclick="sendAJAX()">Bring it!</button>
            </div>
            <ul id="ajax">

            </ul>
          </div>
        </div>
      </div>
    </div>
  </body>
</html>

please help!

Eric Martz
Eric Martz
16,007 Points

Doug,

Can you post which video were you trying to follow?

Thanks, Eric

3 Answers

Dave McFarland
STAFF
Dave McFarland
Treehouse Teacher
Dave McFarland
Dave McFarland
Treehouse Teacher

Hi Douglas Watts

Thanks for pointing this out. What's happening is that when you preview a workspace and you request a file that doesn't exist, the server returns the index.html file. In other words the workspace server NEVER returns a 404 error. This is an unusual behavior that you won't find in most web servers. I believe we will be changing this back to the normal server behavior -- that is, the workspace preview will return a 404 when you request a file that's not found. Stay tuned.

Eric Martz
Eric Martz
16,007 Points

I noticed in the Network section of Dev Tools that no matter what file name I put in I kept getting a 200 status code. Thought I was going crazy.

Dave McFarland
Dave McFarland
Treehouse Teacher
Dave McFarland
Dave McFarland
Treehouse Teacher

Sorry for the confusion Eric Martz

You are NOT going crazy :)

Douglas Watts
Douglas Watts
5,464 Points
Douglas Watts
Douglas Watts
5,464 Points

Eric,

here is the link: http://teamtreehouse.com/library/ajax-basics/programming-ajax/ajax-callbacks - it's at about 5:00 minutes in when he is setting up the alert.

Douglas Watts
Douglas Watts
5,464 Points
Douglas Watts
Douglas Watts
5,464 Points

O.K.,

thanks to both for the effort!