AJAX Now with ASP'NET 2'0

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AJAX Now with ASP.NET 2.0

• Jim Zimmerman

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AGENDA

• Overview of AJAX
• Client Script Callbacks in ASP.NET 2.0
• Demo using Script Callbacks
• Demo using Jason Diamonds Library
• Atlas
• AJAX for .NET 1.1
• Where to go from here?

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Overview of AJAX

• Asynchronous JavaScriptCSSDOMXMLHttpRequest
• Remote Scripting
• Whos Using AJAX
• Google Maps, Gmail, Suggest
• Yahoo Flickr
• Microsoft Outlook Web Client
• Ajax isnt something you can download
• Dont need to use XML

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Client Script Callbacks

• New to ASP.NET 2.0
• Are similar to Postbacks in .NET 1.1
• Works cross-platform.
• ICallbackEventHandler Problems
• Interface has a single method and any callback to
  the page goes back to this single handler
• Single handler has no context to tell which
  control it's dealing with
• The RaiseCallbackEvent method can only accept a
  single string and return a single string

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Demo using Script Callbacks

• Create a delegate for the ICallbackEventHandler
• public MyAjax.EventControl ProductListEventContro
  l new MyAjax.EventControl()
• Generate the client script for the control
• ProductListEventControl.ScriptCallback new
  MyAjax.delScriptCallBack(GetProductDetails)
• ScriptRef this.GetClientScript(ProductListEvent
  Control, "productList", "GetProductDetails")
• this.productList.Attributes.Add("onchange",
  ScriptRef)
• Create JavaScript handler for the result
• function GetProductDetails(Result,Context)
• // alert (Result)
• Detail document.getElementById('divConte
  nts')
• Detail.style.display''
• Detail.innerHTML 'ltpregt' Result
  'lt/pregt'
• Limitations
• ICallbackEventHandler.RaiseCallbackEvent method
  can only accept a single string and return a
  single string

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Demo using Jasons Library

• Jason Diamond created a library that was not
  dependent on use of a separate IHttpHandler
  implementation to process the callback requests
  like what is used in AJAX.NET
• Register the script
• Ajax.Manager.Register(this, "My.Page",
  Ajax.Debug.None)
• Create the c method in the code behind
• Ajax.Method
• public DataSet GetDataSet()
• DataSet ds new DataSet()
• ds.Tables.Add(GetDataTable())
• return ds
• Create the JavaScript
• function PopulateListWithDataSet()
• My.Page.GetDataSet(DoSetCallBack)
• document.getElementById("_popSetButton").value
  "Getting DataSet..."

7
Atlas Client Script Framework

• 100 JavaScript client framework
• Make it real easy for developers
• Will work on all modern browsers
• The Atlas Client Script Framework will include
  the following components
• An extensible core framework that adds features
  to JavaScript such as lifetime management,
  inheritance, multicast event handlers, and
  interfaces
• A base class library for common features such as
  rich string manipulation, timers, and running
  tasks
• A UI framework for attaching dynamic behaviors to
  HTML in a cross-browser way
• A network stack to simplify server connectivity
  and access to web services
• A set of controls for rich UI, such as
  auto-complete textboxes, popup panels, animation,
  and drag and drop
• A browser compatibility layer to address
  scripting behavior differences between browsers.
• http//weblogs.asp.net/scottgu/archive/2005/06/28/
  416185.aspx

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AJAX for .NET 1.1

• http//ajax.schwarz-interactive.de/csharpsample/de
  fault.aspx - Michael Schwarz
• http//jason.diamond.name/weblog/2005/07/06/my-aja
  x-dot-net-library - Jason Diamond

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Where to go from here?

• Think about what situations would be enhanced by
  AJAX style coding
• Download the demo source code and presentation
  at
• http//aspnet2examples.blogspot.com
• Prototype AJAX friendly scenarios