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 11:40:18 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.

 

 

  • Technologies worth knowing
    • HTTP
    • HTML
    • DOM
    • XML
    • JSON

 

  • How it works
    • Asynchronous request.
    • Same old HTTP (Get, Post, etc)

 

HTTP transport mechanism without reloading the page.

NOT strictly XML; any data 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) }

}

 

Use JavaScript 'eval' function to absorb JSON at retrieval time.

 

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. URL: [[http://www.nearwhere.com/guest/]]
  • Mashup of ski resorts and hotels. URL: [[http://skiwhere.com/map/]]

 

  • Excellent XMLHTTPRequest introduction: [[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