AOP in C# 2013
- 3. TOPICS - What is bad and good design ? - Problem statement. - What is AOP ? - Demo
- 4. WHAT IS BAD DESIGN ?
- 5. WHAT IS BAD DESIGN ? -the system is rigid: it's hard to change a part of the system without affecting too many other parts of the system -the system is fragile: when making a change, unexpected parts of the system break - the system or component is immobile: it is hard to reuse it in another application because it cannot be disentangled from the current application
- 9. class GarbageService { public void Transfer(int sourceID, int destinationID, int size) { Storage source = Storage.GetById(sourceID); Storage destination = Storage.GetById(destinationID); var garbage = source.GetGarbage(size); destination.PutGarbage(garbage); } }
- 10. class GarbageService { public void Transfer(int sourceID, int destinationID, int size) { Trace.TraceInformation("Entering GarbageService.Transfer( sourceID={0},destinationID={1})", sourceID, destinationID); try { Storage source = Storage.GetById(sourceID); Storage destination = Storage.GetById(destinationID); var garbage = source.GetGarbage(size); destination.PutGarbage(garbage); } catch (Exception ex) { Trace.TraceError("Exception: GarbageService.Transfer( sourceID = {0}, destinationID = {1}) failed : {2}“, sourceID, destinationID, ex.Message); throw; } } }
- 11. class GarbageService { public void Transfer(int sourceID, int destinationID, int size) { Trace.TraceInformation("Entering GarbageService.Transfer(sourceID = {0}, destinationID = {1})", sourceID, destinationID); if (sourceID <= 0) { throw new ArgumentOutOfRangeException("sourceID"); } if (destinationID <= 0) { throw new ArgumentOutOfRangeException("destinationID"); } if (size <= 0) { throw new ArgumentOutOfRangeException("size"); } try { Storage source = Storage.GetById(sourceID); Storage destination = Storage.GetById(destinationID); var garbage = source.GetGarbage(size); destination.PutGarbage(garbage); } catch (Exception ex) { Trace.TraceError("Exception: GarbageService.Transfer(sourceID = {0}, destinationID = {1}) failed : {2}“, sourceID, destinationID, ex.Message); throw; } } }
- 12. REQUIREMENTS • Functional Requirements • Line-of-business • Non functional requirements • Logging • Caching • Transaction • Validation • Exception Handling • Thread Sync • GUI Binding • … and a lot more!
- 13. WHAT IS AOP ? AOP - is a programming paradigm which aims to increase modularity by allowing the separation of cross-cutting concerns. AOP - an approach that extends OOP and addresses the issue of cross-cutting concerns: • Encapsulate cross-cutting concerns into Aspects. • Improves code reusability, modularity and separation of concerns. • Reduces defects by reducing boiler – plate code. With AOP, you still define the common functionality in one place, but you can declaratively define how and where this functionality is applied without having to modify the class to which you are applying the new feature.
- 14. AOP • doesn’t solve any new problem • it’s just another tool in your toolbox • the main goal is nice separation of concerns • a decrease in development costs and software delivery time; • an increase in application maintainability. • reduce noise in source == more clean model
- 15. AOP TERMINOLOGY • Join Point • place where behavior can be added • Advice • code that can be injected at join points • Point Cut • join points where advices should be applied
- 20. AOP WEAVING • Compile time weaving • Source-Level Weaving • Modifying the MSIL code • Run-Time weaving • Dynamic Proxy
- 21. PostSharp is the most comprehensive aspect-oriented framework for .NET Gael Fraiteur
- 22. Demo
- 24. Philip Laureano
- 25. Comparing Aspect Frameworks STATIC VS DYNAMIC AOP Spring.NET PostSharp LinFu Castle MS Unity/PIAB Build-Time: Hybrid Run-Time: Very Expressive Less Expressive Robust Model Brittle Model Not Invasive Invasive Static Dynamic
- 26. Comparing Aspect Frameworks EXPRESSIVENESS What can you do with the framework? Spring.NET PostSharp Linfu Unity/PIAB Castle Method Interception Yes Yes Yes Yes Private/Sealed Yes Yes Member Interception Event Interception Yes Member Introduction Yes
- 28. We need Aspects!