earth tech

The javascriptkit.com site makes some interesting points about AJAX and the implementation of the responseXML property of the XMLHttpRequest object.

"If you're running an Ajax request offline locally on your PC, a value of 0 is returned by status in most browsers regardless of the actual request status, even if it was successful. To run and test Ajax requests locally, it should overlook the status code being 200, and merely rely on a readyState value of 4. The following example takes into account the request possibly being run offline and to enable it:"

var myrequest = new ajaxRequest()
myrequest.onreadystatechange=function() {
  if ( myrequest.readyState == 4 ) { //if request has completed
    if ( myrequest.status == 200 || 
      window.location.href.indexOf("http") == -1 ) {

      /* if request was successful 
         (versus "page not found" etc) 
         or if run offline (rely on readyState of
         4 alone then) */

      // ... do something with returned data ...

  }
 }
}

From the example, it is clear that the test

window.location.href.indexOf("http") == -1

can be generally useful for other things - like finding the protocol string from the URL of the current document. In theory, at least, this should tell you what protocol was used to load the content of window.

Labels: ajax, javascript, responseXML, XMLHttpRequest

posted by pd wilson   #   15:32

This has got to be the sickist piece of Javascript ever, in the bitniverse. A True Manifestation of The Overmind. Or is that Infestation? Must use this code. http://www.thomasfrank.se/easier_than_ajax.html

Labels: ajax, javascript

posted by pd wilson   #   08:57

A really great blog post about how to do javascript includes using "asynchronous javascript" XMLHTTP requests to server-side PHP scripts.

The article shows how to do 'include_once' and 'on-demand' loading of javascript code, which can be executed by the browser to modify the current document, including by use of HTTP GET request results assigned to the DOM.

Labels: ajax, dom, javascript, php, xml

posted by pd wilson   #   06:25

Wacka-wacka DOOOO!

Today's brain teaser is AJAX + PHP + Javascript + XML + MySQL ... and there may be some others I've left out CSS, XHTML, stuff like that.

Nevertheless, we will prevail. Links to follow.^

• PHP Example - responseXML
• JavaScript and HTML DOM Reference
• XML DOM
• XML Manipulation (from the PHP Manual)

Nothing specific to the MySQL side of this, for now.

Labels: ajax, javascript, mysql, php, w3c, xml

posted by pd wilson   #   03:48