Ajax William Luu Blog:
What is Ajax? Term coined by Jesse James Garrett – 85.phphttp:// 85.php Also known as XmlHttpRequest, Client Script callbacks. Ajax stands for Asynchronous JavaScript And XML. The term represents making use of –XHTML and CSS for UI presentation –JavaScript for manipulating Screen elements –Asynchronous data retrieval using the XmlHttpRequest object Standards based, so works cross browser
Examples services using Ajax GMail – Google Suggest Outlook Web Access – Comes as part of Exchange Server (Available from 1998 – XmlHttpRequest ActiveX object in IE4) Start.com portalStart.com Hotmail Kahuna (next generation Hotmail service) – Not released yet Google Maps - MSN Virtual Earth - Flickr Photo Sharing website –
Postbacks vs Async Script Callbacks With Ajax we can refresh the data on a page without the need to refresh the whole page. This is achieved via usage of DHTML. Let’s say we have a small area on the page that needs to always have near “real time” data. Say flight times, or for a sports website, live a scorecard. This can be achieved via Ajax. With the traditional postback model, when we need to update parts of the page, we have to refresh the whole page. This involves making a request to the server, and then downloading the new page.
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What’s to come from Microsoft ASP.NET 2.0’s Client Script Callback Atlas FireAnt – Atlas was derived/inspired by FireAnt, and used for basis of future MSN properties
What’s available right now for ASP.NET 1.0/1.1 Ajax.NET/BorgWorx Ajax.NET/Ajax.NET Professional – My Ajax.NET WebORB for.NET - Weborb.htm Weborb.htm BitKraft - More: -Side:_.NET -Side:_.NET
Demo of Ajax.NET Available at: – –
Demo of Atlas Available at: – –PDC Presentation by Nikhil Kothari:
A look to the future… Windows Presentation Foundation (WPF) – Formerly Avalon WPF/E (Windows Presentation Foundation /“Everywhere”) – Down level XAML parser which can run cross browser. Available as either an ActiveX plugin for IE or native browser plugin for other browsers Smart Client Macromedia Flash/Flex Laszlo - Xamlon Web -
Last thoughts Think about the possibilities that giving users almost “live” feedback when they interact with the web application you’ve designed and develop. Forget about the traditional postback model for a brief moment and venture into the world of the rich interactive web. The biggest innovations seem to be coming from the web. The web travels at a million miles and hour. Look at the recent global disasters and how fast news about them came flying through the web. Through blogs, as well as online news websites. The web is connecting the world and making our world smaller than it already is.
Ajax Issues What if the user disables ActiveX in IE? Usability issues with onclick (what if the user wants to navigate using a keyboard?) What if user disables Javascript? Default security settings only allow user to access JavaScript hosted on same domain as originating web page. How does the user know when you change something on the UI? Use UI cues to show changes or when script is “busy” doing an update. With great power, comes even greater responsibilities.
Resources Ajax.NET - (Michael Schwarz, Ajax.NET authors' blog - Ajaxian Blog - Ajax: A New Approach to Web Applications (Original Article that coined the Ajax term by Jesse James Garrett) OK/Cancel (Jesse James Garrett): Why Ajax Matters Now - now.htmlhttp:// now.html BitKraft - Dare Obasanjo: Moving Beyond the Basics: Scott Isaacs on AJAX Design Patterns Scott Isaacs: Why Ajax is so 1999? Part Scott Isaacs: Why Ajax is so 1999? Part Omar Shahine: Fireant (Microsoft FireAnt Project) f46630d7.aspxhttp:// 3789f46630d7.aspx SecretGeek: EARWAX anybody?: AJAX and The EARWAX - Ajax.NET under sharepoint (Angus Logan) - Alex Bosworth's Weblog: Ajax Mistakes - Additional resources to blog post (Ajax Mistakes): Cleaning up with Ajax ASP.NET Spiced: Ajax - Omar Shahine: FireAnt - Scott Guthrie: Atlas Project - fiftyfoureleven.com: XMLHttpRequest & Ajax Working Examples Brock Allen: ICallbackEventHandler vs AJAX.NET a848d821http://staff.develop.com/ballen/blog/CommentView.aspx?guid=c35c43f ee a848d821 Bertrand Le Roy: Fun with callbacks Part 1: What's in the ASP.NET box? - Paul Glavich: Asynchronous client script callbacks - Luke Wroblewski: Ajax Interface Design – Ajax Patterns Wiki - Microsoft Atlas Project: More on Atlas: –Atlas PDC presentation slides and demos (Nikhilk Kothari): –Atlas XML Script: –Atlas Architecture Overview: –Microsoft Gadgets -
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