Migrating Existing ASP Applications to ASP.NET

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Migrating Existing ASP Applications to ASP.NET

• An in-depth look at the paradigm shiftsand
  upgrade strategies when moving from ASP to
  ASP.NET architectures.
• By
• Carl Prothman
• Microsoft Most Valuable Professional (MVP)
• Certified Computer Professional (CCP)

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Introductions

• Carl Prothman
• Microsoft Most Valuable Professional (MVP)
• Visual Basic MVP 1998/2002
• ASP.NET MVP 2002/2003
• Certified Computer Professional (CCP)
• Microsoft Certified Professional (MCP)
• Over 22 years of experience in Software Industry
• Bachelor of Science in Aeronautics and
  Astronautics (BSAA) from University of
  Washington
• Email carlpr_at_spamcop.net
• Able Consulting, Inc.
• Owner http//www.able-consulting.com

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Agenda

• .NET Overview 1 min
• What is it?
• Paradigm Shifts 35 mins
• Top 10 (make that 11)
• Migration Strategies 15 mins
• Side-by-Side Conversion
• Tier-by-Tier
• Summary 9 mins
• QA
• 
  Total 60 mins

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Overview

• What is Microsofts .NET?
• Set of Microsoft software technologies connecting
  your world of information, people, systems, and
  devices
• Enables an unprecedented level of software
  integration through the use of XML Web services
• Small, discrete, building-block applications
• Connected to each other via the Internet
• What is ASP.NET?
• The development platform for building
  server-based Web applications
• Web Forms and XML Web Services
• HTTP Runtime Architecture with IIS

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ASP.NET Overall View
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Agenda

• .NET Overview
• Paradigm Shifts 25 mins
• Migration Strategies
• Summary

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ASP.NET Paradigm Shifts

• What is a Paradigm Shift?
• A set of concepts, values, practices and
  assumptions that constitutes a way of viewing
  reality for the community that shares them.
• When one paradigm looses influence and another
  paradigm takes over, then there is a paradigm
  shift!
• Knowing in advance how a Paradigm Shift might
  occur gives you an advantage over others!

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ASP.NET - Paradigm Shift0) Remote Application
Communication

• In ASP, you used the RDS DataSpace to communicate
  to a remote COM Component over DCOM or HTTP(S)
• RDS is a major security hole!
• RDS DataFactory MS99-025
• RDS Data Stub MS02-065
• In ASP.NET, you now use an XML Web Services to
  communication to remote applications
• Standard protocol (SOAP) for distributed
  environments
• Over HTTP with XML SOAP Envelop / Payload

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ASP.NET - Paradigm Shift1) Server-Side Web
Controls

• In ASP, you used Response.Write or lt to
  send HTML / script to the Web browser
• In ASP.NET, you can now program against
  server-side Web Controls which generate the HTML
• HTML Server Controls
• HTML Tag with and ID and RunAtServer
  attributes
• Web Server Controls
• ASP.NET control with ID and RunAtServer
  attributes
• Form Validation Controls
• Client-side and Server-side Validation
• User Control Page (.ASCX)
• Replaces the HTML Include command
• Custom Control Assembly (.DLL)

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ASP.NET - Paradigm Shift2) Automatic HTML Code
Generation

• In ASP, you created custom pages for each browser
  type
• Use browscap.ini file with the BrowserType object
• In ASP.NET, you use server-side Web Controls and
  Web Forms to generate the HTML
• ASP.NET figure out the browser type
• Automatically renders the correct,
  browser-compliant HTML for features such as
  Styles, Layout, and so on.
• In Visual Studio .NET, set TargetSchema Property
  on the Page
• Internet Explorer 3.02 / Navigator 3.0
• Internet Explorer 5.0
• Navigator 4.0

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Paradigm Shift3) Automatic Web Control State

• In ASP, you had to fill the control with user
  entered values on POST back
• Show the web page again with an error message
• In ASP.NET, the controls automatically retain the
  user entered values on POST back
• ViewState is used to store Control State
• User selection, Control Info
• Control values are automatically filled in for
  you during post back.
• Can store values in ViewState between round trips
• Must only use one FORM on page
• Must post to the same page for ViewState to work!

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Paradigm Shift4) HTML Separate from Code

• In ASP, you could mix HTML with client-side and
  server-side script
• Hard to read and maintain
• Some used .vbs or .js files to separate out
  the script
• In ASP.NET, you can either
• Put the code in-line with SCRIPT tags
• Or put code in a code-behind page
• Visual Studio .NET creates code-behind pages by
  default
• ASP.NET Web Matrix creates in-line SCRIPT tags by
  default

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Paradigm Shift5) Compiled ASP.NET Code

• In ASP, you used server-side VBScript (or
  JavaScript) which was interpreted, hence slower!
• So most folks just pulled the server-side script
  out and put it into a VB 6.0 / C COM
  Components (N-Tier)
• Presentation Tier Classes
• Business Tier Classes
• Data Tier Classes
• In ASP.NET, everything is compiled, which is
  faster!
• In-line SCRIPT tags with RunAtServer
• Code Behind page (must compile)
• Debug vs- Release mode

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Paradigm Shift6) Registering Client-Side Script

• In ASP, you could directly add client-side event
  handlers to HTML controls
• In ASP.NET, you add client-side event handlers to
  Web Controls via Attribute.Add
• Button1.Attributes.Add(onclick,
  alert(Hello))
• You can also register a client script block
• RegisterClientScriptBlock
• Client-side JavaScript / JScript
• VBScript

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Paradigm Shift7) User Controls Instead of
Includes

• In ASP, you used includes files to include common
  script code
• In ASP.NET, you now use User Controls (ASCX) for
  common code
• Headers, Footers, etc..
• Public Properties and Methods
• Inheritance from BaseControl
• Reuse common Properties, Methods, and settings

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Paradigm Shift8) XML Configuration Files

• In ASP, you used System Registry (or IIS Metadata
  db) to store Application settings
• In ASP.NET, you use XML files to store
  Application settings
• Machine.config (for all projects on the machine)
• C\WINNT\Microsoft.NET\Framework\v1.0.3705\CONFIG\
  machine.config
• Web.config (for each project)
• Read in configuration settings using
• System.Resources.ConfigurationSettings.AppSettings
  myKeyName"

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Paradigm Shift9) ASP.NET Worker Process

• In ASP, IIS used the ASP.DLL to handle each web
  request
• In ASP.NET, IIS calls an ASPNET worker process
  (aspnet_wp.exe)
• Identity of ASP.NET Worker process controlled by
• machine.config, processModel element, userName
  attribute
• C\WINNT\Microsoft.NET\Framework\v1.0.3705\CONF
  IG\machine.config
• "MACHINE" runs as low privilege user account
  named "ASPNET".
• "SYSTEM" runs as localsystem (high privilege
  admin) account.
• Running IISRESET stops the Worker process

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Paradigm Shift10) Windows Impersonation

• In ASP, impersonation was enabled by default
• Using Anon Access, ASP would impersonate
  IUSR_XXXX
• Using NTLM / Basic, ASP would impersonate calling
  User
• In ASP.NET, impersonation is disabled by default
• You must explicitly enable impersonation in
  web.config or machine .config file
• ltauthentication mode"Windows" /gt
• ltidentity impersonate"true" /gt
• System.Security.Principal.WindowsIdentity.GetCurre
  nt().Name
• CARLP7\ASPNET (ASP.NET User account)
• CARLP7\IUSR_CARLP7 (IIS Anon User account)
• CARLP7\Administrator (User account that Im
  logged as)

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Agenda

• .NET Overview
• Paradigm Shifts
• Migration Strategies 20 mins
• Summary

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Migration Strategies Side-by-Side

• ASP and ASP.NET Side-by-Side
• Both ASP and ASP.NET files can run side-by-side
  in same IIS Web Application
• However, you cannot share Session variables
  between them directly
• Steps to convert ASP to ASP.NET
• Rename the ASP file to use the .ASPX file
  extension
• Browse to the page and update server-side code as
  needed
• Option Explicit is the default. Remove Option
  Explicit line.
• Method calls with parameters require ( and ).
• Dont need Set or Let anymore. Remove them.
• For ADO/COM objects, use aspcompattrue in the
  Page directive
• must have spaces around it. No more s
  str1str2
• No more Default Properties. Must state
  explicitly oRs(0).Value
• No more VBScript Variants gt Objects / .NET
  Framework Class Library
• ByValue is now the default. Was ByRef in VB 6.0.
• VB.NET is now 0 based. Was 1 based (in some
  cases) in VB 6.0
• Integer data type is now 32 bits. Was 16 bit in
  VB 6.0

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Migration Strategies- Tier by Tier

• First Convert the UI Tier
• Create new WebForms / User Controls
• Call existing COM Components
• Next Convert the Business Tier
• Create Class Modules for each Business class
• If Internet clients need to reuse these new
  classes, create XML Web Services wrappers
• Finally Convert Any Desktop Database
• Upgrade your old Access MDB to MSDE or SQL Server

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Agenda

• .NET Overview
• Paradigm Shifts
• Migration Strategies
• Summary 5 mins

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Summary

• Reviewed ASP.NET Paradigm Shifts
• Top 10 (make that 11)
• But there are a lot more
• Reviewed Migration Strategies
• Side by Side Conversion
• Tier by Tier Conversion
• Better understanding of ASP to ASP.NET Migration
  Issues

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Questions?

• Q A
• More Information
• ASP.NET Web Site http//www.asp.net
• GotDotNet Web Site http//www.gotdotnet.com
• These slides / sample code are at
• http//www.able-consulting.com/