Prototype Prototype

if the server (as mine) use the http cache control headers like Etag/Last-Modified/Expires
The PeriodicalUpdater don't care and update the html with its old value.

This would be an Improvment in performance if the request was not done or when no change the update of html was not done.

to do this well I've made a class like that :
@@@javascript Ajax.Ressource = Class.create({
initialize:function(uri,options){

this.uri = uri;
this.options = options;
this.headers={};
this.refresh();

}, dontRefreshBefore:new Date(0), refresh:function(){

if(this.dontRefreshBefore>new Date()) return;
var opt = Object.extend({},this.options);
opt = Object.extend(opt,{
  requestHeaders:this.headers,
  onComplete:function(response,json){
    this.headers['If-None-Match'] = response.getHeader('Etag');
this.headers['If-Modified-Since'] = response.getHeader('Last-modified');
var expire = response.getHeader('Expires');
if(expire){
      var expirationdate = Date.parse(expire);
      var now = Date.parse(response.getHeader('Date'));
      this.dontRefreshBefore=new Date()+(expirationdate-now);         
}
    //TODO add header etag
    if(response.status!=='304'){
      this.options.onComplete(response,json);
    }  
  }.bind(this)
});
new Ajax.Request(this.uri,opt);

}
});

and my own Updater using this Ajax.Ressource.







But maybe its worth being putted in prototype and in the PeriodicalUpdater.