Ajax Object

• Create and send a request with:

var url = '/proxy?url=' + encodeURIComponent('http://www.google.com/search?q=Prototype');
// notice the use of a proxy to circumvent the Same Origin Policy.

new Ajax.Request(url, {
  method: 'get',
  onSuccess: function(transport) {
    var notice = $('notice');
    if (transport.responseText.match(/href="http:\/\/" href="http://prototypejs.org/" 
              title="Linkification: http://prototypejs.org/">prototypejs.org/))
      notice.update('Yeah! You are in the Top 10!').setStyle({ background: '#dfd' });
    else
      notice.update('Damn! You are beyond #10...').setStyle({ background: '#fdd' });
  },
  parameters: parametersObject, //contains properties+values which will be sent in request.
  postBody: uploadStuff, //it method=post this is the stuff to upload
  requestHeaders: object, //define your own headers
  onComplete: function (t) {
        //completion does not imply success or failure
    },
  onFailure: function (t) {
      //we failed.
    }
});

• If you send back javascript, it will be automatically evaled.
• To keep an eye on all XHR calls use the Ajax.Responders.register or unregister.

Ajax.Responders.register({
  onCreate: function() {
    Ajax.activeRequestCount++;
  },
  onComplete: function() {
    Ajax.activeRequestCount--;
  }
});

• If you are sending back XHTML to put in the page then:

//Send contents of id="text" element to server at url=/items
// use reply to populate id="items" element, by appending child
new Ajax.Updater('items', '/items', {
  parameters: { text: $F('text') },
  insertion: Insertion.Bottom
});

• If you want to keep polling:

new Ajax.PeriodicalUpdater('items', '/items', {
  method: 'get', 
  frequency: 3, 
  decay: 2
});