title: XmlHttpRequest.responseText while loading (readyState==3) in Chrome
body: <p>I am trying to "streaming" (from server to client) in Javascript by ajax (by XmlHttpRequest (=xhr). I am using modified handleResponse function described in
  <a href="https://stackoverflow.com/questions/1112413/cross-browser-implementation-of-http-streaming-push-ajax-pattern">Cross-browser implementation of &quot;HTTP Streaming&quot; (push) AJAX pattern</a></p>
  
  <pre><code>function handleResponse() {
  if (http.readyState != 4 &amp;&amp; http.readyState != 3)
      return;
  if (http.readyState == 3 &amp;&amp; http.status != 200)
      return;
  if (http.readyState == 4 &amp;&amp; http.status != 200) {
      clearInterval(pollTimer);
      inProgress = false;
  }
  // In konqueror http.responseText is sometimes null here...
  if (http.responseText === null)
      return;
  
  while (prevDataLength != http.responseText.length) {
      if (http.readyState == 4  &amp;&amp; prevDataLength == http.responseText.length)
          break;
      prevDataLength = http.responseText.length;
      var response = http.responseText.substring(nextLine);
      var lines = response.split('\n');
      nextLine = nextLine + response.lastIndexOf('\n') + 1;
      if (response[response.length-1] != '\n')
          lines.pop();
  
      for (var i = 0; i &lt; lines.length; i++) {
          // ...
      }
  }
  
  if (http.readyState == 4 &amp;&amp; prevDataLength == http.responseText.length)
      clearInterval(pollTimer);
  
  inProgress = false;
  }
  </code></pre>
  
  <p>With php script, which flushes me data (without ajax it really flushes data to browser while progressing)</p>
  
  <p>I have no problem in Firefox, but Google Chrome and IE give me an empty responseText while xhr.readyState equals to 3. I found that problem described in the Internet, but it didn't give me any solution.</p>
  
  <p>Do you know, how to pass by this implementation problem in Chrome? (w3c says, that responseText can't be NULL in readyState==3 - Chrome implemented this rule, but gives only empty string)</p>
  
  <p>And if you don't know, do you know any working solution in some products? (opensource frameworks, librararies etc.)</p>
  
  <p>Thanks a lot for your ideas.</p>
  
  <p><strong>Edit:</strong>
  The workaround is in creating iframe, call the script to iframe and flush data here and grab data by javascript from iframe. But this is not ajax solution. I really would like to see pure ajax solution.</p>