From DNA to.NET Design Path

Objectives Sketch up a typical Win DNA Application Sketch up the.NET version Compare Design and Implementation Advantages of.NET Migration from WinDNA to.NET Design Guidelines to Build Windows DNA applications ready for.NET Have a smooth migration Definition of a Migration Strategy

Contents Section 1: Windows DNA Reference Application Section 2: Microsoft.NET Reference Application Section 3: WinDNA vs..NET Design Section 4: Migrating WinDNA to.NET Section 5: WinDNA Design Guidelines Section 6: Migration Guidelines Summary Questions

Section 1: Windows DNA Reference App WinDNA Sample Application DNA Web Application User Interaction DNA Service Application Background Database Updates DNA Web Service Offer 3rd Party Data

WinDNA Web Application Design IIS 5.0 Presentation Layer COM+SQL Server Business LogicData Layer Transporter ASP Business Rules Data Abstraction Stored Procedures Tables (D)COM / XML ADO HTML

WinDNA Service Application & Web Service Design Win32 Application SQL Server Stored Procedures Tables ADO Web Service ASP Listener COM+ Service Implementation SOAP (D)COM / XML

Section 2: Microsoft.NET Reference App Design of the.NET Web Application Design of the.NET Service Application Design of the.NET Web Service

.NET Web Application Design IIS 5.0 Presentation Layer.NET ComponentsSQL Server Business LogicData Layer Transporter ASP.NET Web Forms Business Rules Data Abstraction Stored Procedures Tables DataSet ADO.NET HTML

.NET Service Application & Web Service Design.NET Application SQL Server Stored Procedures Tables ADO.NET Web Service ASP.NET SOAP

Section 3: WinDNA vs..NET Design Compare Web Applications Differences Advantages of.NET Compare Service Applications Differences Advantages of.NET Compare Web Services Differences Advantages of.NET

Web Application Design Differences Similarities Three tiers Business layer divided into three parts HTML User Input Database access via Stored Procedures ASP has become ASP.NET No more (D)COM components DataSets instead of XML Documents ADO is replaced by ADO.NET

Advantages of.NET 1/4 ASP.NET Separation of Layout and Code Object-oriented Programming Model Entire.NET Framework platform available Advanced Session State Management Compiled Code, improved Performance Rich debug and trace Facilities Author in any.NET compatible Language

Advantages of.NET 2/4 No more (D)COM Components No more Registry Entries No more HRESULTS, GUIDS, IUnknown,... No more Conversation to Types recognized by COM The End of DLL Hell DataSets instead of XML Documents No more Conversion inside the Application

Advantages of.NET 3/4 ADO.NET Interoperability through use of XML Open standard Human readable and decipherable text Performance Advantages relative to ADO COM marshalling Data passed as Text (XML) No Conversation to Types recognized by COM

Advantages of.NET 4/4 Summary Improved Time-To-Market Improved Productivity Improved Quality Improved Scalability Improved Performance Improved Maintenance

Service Application Design Differences Similarities Database access via Stored Procedures Web Service access via SOAP.NET Application ADO is replaced by ADO.NET

Advantages of.NET 1/2.NET Application.NET Framework New Design Features (Sizing) Freedom of Language Choice Ease of using ADO.NET Ease of consuming Web Services ADO.NET Interoperability through use of XML Performance advantages relative to ADO COM marshalling

Advantages of.NET 2/2 Summary Improved Time-To-Market Improved Productivity Improved Maintenance

Web Service Design Differences ASP has become ASP.NET No (D)COM Component

Advantages of.NET 1/3 ASP.NET Object-oriented Programming Model Entire.NET Framework platform available Web Service natively supported Compiled Code, improved Performance Rich debug Facilities Author in any.NET compatible Language

Advantages of.NET 2/3 No (D)COM Component No more Registry Entries No more HRESULTS, GUIDS, IUnknown,... No more Conversation to Types recognized by COM The End of DLL Hell

Advantages of.NET 3/3 Summary Improved Time-To-Market Improved Productivity Improved Quality Improved Performance Improved Maintenance

Section 4: Migrating WinDNA to.NET Step 1: ASP to ASP.NET Step 2: COM+ to.NET Component Step 3: MSXML to.NET XML Classes Step 4: ADO to ADO.NET possible further improvements using.NET specifics

Step 1: ASP to ASP.NET Separated into two Parts Transform.asp into.aspx Files Extract Code into code-behind Classes

Transform.asp into.aspx Files 1/2 Automatically done Migration of Visual InterDev Projects to VS.NET Page Directives inserted To do manually Set Language and SessionState Directive Move Code into correct Tags Create PageLoad Event Handling Watch out for Syntax Changes

Transform.asp into.aspx Files 2/2 Strong recommendations Leverage exception handling Leverage tracing features Benefits Compiled ASP‘s Ready for Debugging Updates made easy

Move Code into code-behind Classes 1/2 No Wizard Support To do manually Check for Code includes Create Helper and / or Base Classes Add strong Data and Function Types Decide Accessibility of Class Members

Move Code into code-behind Classes 2/2 Benefits Clean Code Easy to extend Easy to maintain Less error prone Reusable Classes...

Step 2: COM+ to.NET Components 1/3 Automatically done Wizard convert Projects and Classes Wizard corrects Code to comply with Visual Basic.NET Syntax Migration Report To do manually (Logic Layer) Inherit from System.ServicedComponent Object Instantiation Interface Implementation Cast of Value Type and String Return Values Global Modules Transaction Handling

Step 2: COM+ to.NET Components 2/3 To do manually (Presentation Layer) Add Reference to Project Add Import Statement Change Object Instantiation Mark Parameters passed by Reference Strong recommendations Rename components Apply naming conventions Provide registration support page

Step 2: COM+ to.NET Components 3/3 Benefits No more Registry Entries No more Conversation to Types recognized by COM The End of DLL Hell no DLL Locks, better turn-around-handling easy Updates, easy deployment

Step 3: MSXML to.NET XML Classes No Wizard Support To do manually Identify the Classes needed Create Helper to encapsulate commonly used Functionality Replace the Code Benefits Improved Performance Several independent Navigators on one Document No DLL Hell

Step 4: ADO to ADO.NET No Wizard Support To do manually Change central Method to execute Stored Procedure Replace Calls on RecordSets with Calls on DataSets DataReader is not appropriate here Remove RecordSet-to-XML Transformation Benefits Database Resources handled by ADO.NET No more Transformation RecordSet / XML Application wide use of DataSets No DLL Hell

Possible further improvements Web Forms ASP.NET Server Controls Validation Controls User Controls DataBinding Caching Benefits Same Programming Model as Win Forms Support of different Client Types Rapid UI Development

Section 5: WinDNA Design Guidelines 1/2 Consider Windows DNA Design Guidelines Avoid Client-side Scripting Strict Separation of Presentation and Logic inside ASP As less Script Code as necessary Give each Peace of Code as single, well-defined Responsibility Put global Code into Functions / Classes Use XML / XSLT instead of Script Code Avoid Attributes in XML Documents

Section 5: WinDNA Design Guidelines 2/2 Be familiar with OOD / OOP Concepts Use all OO abilities of VB6 As much Class Modules as possible As less Global Modules as needed Put common Functionality into global Modules E.g Access to Stored Procedures Get familiar with Visual Basic language changes Avoid things that don’t match quite well in VB.NET

Section 6: Migration Guidelines Do‘s Check whether to migrate at all Decide what and when to migrate Take the Chances Separate the Migration into small Pieces Handle PageLoad Event Don‘ts Migrate a whole Application in one single Step Migrate just for the sake of having migrated

Summary Become familiar with.NET Concepts Smooth Migration needs a prepared WinDNA Application Not all Migration Work can be done by Wizards.NET offers great Improvements, which makes Migration worth it Helps you to do a good Job Keeps your Customers satisfied Supports your Business

Questions?

Appendix: Exploring the Sample App WinDNA Stock Application Build for Educational Purposes Used over the Internet Scalable Throughput Easy Maintenance Step by Step Migration Reflects the Steps described