Introduction to aspect oriented programming in .net

1. Introduction To
Aspect Oriented
Programming
Present in Tabriz Software Open Talks
Saeed Shargi Ghazani
@saeed_shargi

2. Problem

3. DRY

4. Solutions
Some techniques include :
 TemplateMetaprogramming
 MetaObjectProtocol
 Decorators
 TemplateMethodPattern
 RPC tools
 Many of the Creational Patterns
 MultipleInheritance and MixIns
 ContextObject or ExplicitManagementOfImplicitContext

5. Solutions
 Programming paradigm solution deal with this problem is :
Aspect Oriented Programming

6. History
 Gregor Kiczales and colleagues at Xerox PARC in 1997
 In 2001, the AspectJ extensions brought AOP to Java
 IBM research team in 2001 proposed Hyper/J
 Microsoft Transaction Server by EJB

7. Intro
 Software development technique that :
 Increase modularity
 Managing cross cutting concerns
 Infrastructure composition

8. Features
 Cross-Cutting Concerns
 Pieces of functionality that are used across multiple parts of a system
 Cross-Cutting concerns and nonfunctional requirements have a lot of overlap
 Advice
 Code that performs the cross-cutting concerns
 “What” of AOP
 Pointcut
 Join Point : Defined between logical steps
 “Where” of AOP

9. Features
 Tangling
 When cross-cutting concern code mixed with core code
 Scattering
 when cross-cutting concern code used in multiple methods
 Weaving
 combination of core codes with aspects

10. Features

11. Features

12. Benefits
 Clean Code
 Reduce Repetition
 Encapsulation

13. Aspects
 Encapsulating
 Wrapper
 SRP
 Decorator Pattern
 OCP

14. Aspects Lifetime
 OnStart
 OnSuccess
 OnExit
 OnError

15. Types
 Interceptors
 IL Code Weaving

16. Interceptors
 Calls to class methods or properties
 IoC Container
 No post compilation
 Dynamic Proxy

17. Interceptors
 Common use of IoC Conainer
Calling Code IoC Container
IMyInterface
MyClass :IMyInterface

18. Interceptors
 Use of IoC Conainer with Dynamic Proxy
Calling Code IoC Container
IMyInterface
MyClass:IMyInterface
Dynamic Proxy
ProxyInterceptor:IMyInterface
ProxyInterceptor:IMyInterface

19. IL Code Weaving
 Run after compilation
 Post process

20. IL Code Weaving
 Common Tool to use :

21. Example
 Simple example in C# with Autofac IoC Container code’s is here
SayHelloToAOP

22. Resources
 AOP in .NET, Matthew D. Groves, Manning Publications Co, 2013
 Aspect Oriented Programming in .NET, Donald Belcham, Plurarsight, 2011
 http://c2.com/cgi/wiki?CrossCuttingConcern
 http://en.wikipedia.org/wiki/Aspect-oriented_programming