Refactoring to a SOLID Foundation

St Louis Day of .NET 2011

Refactoring to a SOLID Foundation

Steve BohlenSenior Software EngineerSpringSource/VMware

E-Mail: [email protected]: http://blog.unhandled-exceptions.comTwitter: @sbohlen


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Indulge Yourself!


Get your LEARN on!


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http://spkr8.com/t/8095


Who am I?• …and why should you care?• Steve Bohlen• I Read Books + Write Software• vs. “Read Software + Write Books”

• Blog, Screencast, Speak, Share, Learn


Steve BohlenNearly 20 years developing softwareLISP, Delphi, C/C++, VB, VB.NET, C#Senior Engineer Springsource/VMwareCo-Founder, NYC Alt.Net User Group

http://nyalt.netCo-Organizer, NYC DDD User Group

http://dddnyc.orgContributor: various OSS projects

NHibernate http://www.nhforge.orgNDbUnit http://www.googlecode.com/ndbunitSpring.NET http://www.springframework.net

blog: http://blog.unhandled-exceptions.come-mail: [email protected]: @sbohlen

CYND D D


RAD Controls for ASP.NET AJAX

RAD Controls for Silverlight

RAD Controls for Windows Phone

RAD Controls for Winforms

RAD Controls for WPF

Telerik Reporting

Telerik OpenAccess ORM

Telerik JustCode

Telerik JustMock

Telerik Extensions for ASP.NET MVC

Test Studio Express

Telerik TeamPulse

Telerik Test Studio

Sitefinity CMS

Telerik JustDecompile

C#/VB.NET Converter

ASPX to Razor Converter


•Disciplined technique•Restructuring an existing body of code•Altering its internal structure without changing its external behavior•A series of small behavior-preserving transformations•Each 'refactoring’ does little by itself•A sequence of transformations can produce a significant restructuring•Each refactoring is small so it's less likely to go wrong•The system is kept fully working after each small refactoring

Refactoring


Refactoring Tools•Developer Express CodeRush

http://devexpress.com/coderush

•JetBrains Resharperhttp://www.jetbrains.com/resharper/

•Telerik JustCodehttp://www.telerik.com/products/justcode.aspx

•Visual Studio Professional

•Notepad!


Introduction to S.O.L.I.D.

SOLID

ingle Responsibility PrincipleRPCPSPSPIP

pen-Close Principle

iskov Substitution Principle

nterface Segregation Principle

ependency Inversion Principle



SOLID

ingle Responsibility Principle

pen-Close Principle





Single Responsibility Principle

There should never be more than one reason for a class to change.


Refactoring to a S.O.L.I.D. Foundation

SRP Demo



SOLID


pen-Close Principle





Open-Closed Principle

Software Entities (Classes, Modules, Functions, etc.)should be Open for Extension, but Closed

for Modification.



OCP Demo



SOLID


pen-Close Principle





Liskov Substitution Principle

If for each object o1 of type Sthere is an object o2 of type T such thatfor all programs P defined in terms of T,

the behavior of P is unchanged when o1 is substituted for o2, then S is a subtype of T.WTF ?!?


Liskov Substitution Principle

Functions that use pointers or references to base classes must be able to use objects of

derived classes without knowing it.



LSP Demo



SOLID


pen-Close Principle





Interface Segregation Principle

Clients should not be forced to depend upon interfaces that they do not use.



ISP Demo



SOLID


pen-Close Principle





Dependency Inversion Principle

High Level Modules should not dependupon Low Level Modules. Both should

depend upon abstractions.

Abstractions should not depend upon details. Details should depend upon abstractions.



DIP Demo


Thinking About Re-Assembly

Presto!


Dependency Injection Frameworks• StructureMap• Spring.NET• Castle Windsor• NInject• Funq• Unity• More…



Closing Thoughts


fini

Steve BohlenSenior Software EngineerSpringSource/VMware

E-Mail: [email protected]: http://blog.unhandled-exceptions.comTwitter: @sbohlen

http://spkr8.com/t/8095

Refactoring to a SOLID Foundation

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