Aspect-Oriented Programming with Dependency Injection Mark Seemann - PowerPoint PPT Presentation

Aspect-Oriented Programming with Dependency Injection Mark Seemann @ploeh

Cross-Cutting Concerns Security Security Auditing Auditing Logging Logging Caching Caching Metering Metering Stability patterns Stability patterns Transactions Transactions

Objective • Single Responsibility Principle • Open/Closed Principle SOLID • Liskov Substitution Principle • Interface Segregation Principle • Dependency Inversion Principle DRY •Don’t Repeat Yourself

Staying SOLID • Single Responsibility Principle • Open/Closed Principle SOLID • Liskov Substitution Principle • Interface Segregation Principle • Dependency Inversion Principle DRY •Don’t Repeat Yourself

Prerequisite Program to an interface, not an implementation - Design Patterns, 1995

Conjecture • It’s always possible to apply a Decorator to an interface

Using Decorators to add aspects Client IFoo ConcreteFoo

Using Decorators to add aspects IFoo AuditingFoo Client IFoo ConcreteFoo

Using Decorators to add aspects IFoo SecureFoo IFoo AuditingFoo Client IFoo ConcreteFoo

Staying SOLID with Decorators DEMO

Staying SOLID • Single Responsibility Principle • Open/Closed Principle SOLID • Liskov Substitution Principle • Interface Segregation Principle • Dependency Inversion Principle DRY •Don’t Repeat Yourself

Staying DRY • Single Responsibility Principle • Open/Closed Principle SOLID • Liskov Substitution Principle • Interface Segregation Principle • Dependency Inversion Principle DRY •Don’t Repeat Yourself

Dynamic interception From here Commonly on, dynamic supplied by interception a DI is required Container

DI Containers with Interception Castle Unity Windsor Spring.NET LinFu

Using a DI Container DEMO

Interception Xyz

Interception IFoo XyzFoo Xyz Xyz

Interception IFoo XyzFoo Xyz IBar Xyz XyzBar Xyz

Interception IFoo XyzFoo Xyz IBar Xyz XyzBar Xyz IBaz XyzBaz Xyz

Adding interceptors DEMO

Pointcut IFoo ConcreteFoo Xyz IBar Abc ConcreteBar IBaz Æøå ConcreteBaz

Pointcut IFoo ConcreteFoo Xyz IBar Match Abc ConcreteBar IBaz Æøå ConcreteBaz

Adding a pointcut DEMO

Objective • Single Responsibility Principle • Open/Closed Principle SOLID • Liskov Substitution Principle • Interface Segregation Principle • Dependency Inversion Principle DRY •Don’t Repeat Yourself

Staying Staying DRY SOLID only requires requires dynamic loose interception coupling

http://blog.ploeh.dk/ @ploeh MARK SEEMANN