log inhelp

  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • You already know Dokkio is an AI-powered assistant to organize & manage your digital files & messages. Very soon, Dokkio will support Outlook as well as One Drive. Check it out today!

View
 

BarCampSFAJAXIntro

This version was saved 17 years, 9 months ago View current version     Page history
Saved by PBworks
on June 24, 2006 at 11:29:56 am
 

Intro

 

  • What is AJAX?
    • Heart is XHR
    • AJAX is a marketing term describing use of XHR optionally with orthogonal technologies such as drag + drop, et al...

 

  • What is it not?
    • Not a panacea.

 

  • History (concepts, before and after ajax)
    • Updating content without user interaction
      • Before: Reload the page via JavaScript or Meta Refresh html tag
      • After: Asynchronous (behind the scenes) data querying.
    • Dynamic user interface
      • Heavy server-side generation of user interface.
      • Lightweight, faster-feeling interfaces1

 

 

  • What is XHR?

 

XHR: xmlhttprequest object

  • Invented by Microsoft
  • Not standardized
  • Widely implemented. IE, Opera, Safari, and Mozilla have this.
  • Today: Quite common feature of any browser with even small market presence.

 

  • Future

**http://barcamp.org/FastAJAX

 

 

* Technologies worth knowing

o HTTP

o HTML

o DOM

o XML?

o JSON

* How it works

o Asynchronous request.

o Same old HTTP (Get, Post, etc)

HTTP transport mechanism without reloading the page.

NOT strictly XML; any format will do.

XML, HTML, JSON: 3 popular formats for data

XML is familiar.

HTML is familiar.

JSON is javascript literal object notation eg:

myobject = {

'properties' : 'hello',

attributes : 'world',

go : function () { alert(this.properties + ' ' + this.attributes) }

}

 

**

 

Eval it and you can get complex interactions.

Sessions and cookies work as you would normally expect on a normal webpage.

 

Benefits:

Faster, lighter interactions. Less weary on users. Do more with less.

Faster implementation??

 

Disadvantages:

Potentially dangerous, easily confounded, won't work without javascript,

inaccessibility problems, UI abuse eg breaking the back button.

 

* Examples

References:

http://barcamp.org/FindPage?SearchFor=Ajax

http://barcamp.org/10SecondAjax

 

Put your hcard on a map. Instant Disposable Map

http://www.nearwhere.com/guest/

Mashup of ski resorts and hotels.

http://skiwhere.com/map/

 

Excellent XHR intro

http://jibbering.com/2002/4/httprequest.html

 

Good simple example of how it works.

http://www.dichotomize.com/czmap/gbold.html

 

Popular Examples:

http://flickr.com

http://gmail.com

http://local.google.com

 

 

* Prototype example?

Printable version