IoC/DI in ActionModularization – Service Locator – Abstract Factories … and SL 4

Eng. Giorgetti AlessandroSoftware ArtisanSID s.r.l.

Two words about me

Graduated EngineerOwner/co-founder of SID s.r.l.Blog: http://www.primordialcode.comEmail: guardian@nablasoft.comTwitter: @A_Giorgetti

Giorgetti Alessandro

Engineering an Application

To be able to use an IoC/DI framework effectively you need to structure your application the right way!Your first problem is an Architectural problem:

How to partition an application?How to structure each module?What are the interactions?Dependencies?…

Engineering an Application

Only When you’ve answered those questions, you can think of how to implement the solution!

Only at this stage you can start thinking of which ‘tool’ to use and which ‘best practice’ you can follow to solve your problems!

Application Architecture

When you think of an application architecture, usually this is the first thing it come into your mind:

DAL

Business Logic

User Interface

Secu

rty

Logg

ing

InfrastructureRIGHT!….but also WRONG!

Application Architecture

When using a IoC/DI container your application sounds more like this:

Security ServiceIService1Module1

Logging ServiceIService2Module2

Infrastructure

Shell

Application Framework

IService3 Messaging Service

Application Architecture

When implementing a module/service

Module1

Module2

Infrastructure

Shell

Application Framework

DAL

Business Logic

User Interface

Secu

rty

Logg

ing

Infrastructure

Hints when building an Architecture based on IoC

Keep things simple!Use a top-down approach while defining and designing the applicationBreak the application in modules / features and decouple the more you can: reusability, easy implementationThink using ‘interfaces’ (do not try to implement anything at this stage)…but avoid over-engineering

Problems – Architectural level

Design Interfaces

Component configuration, creation, lifecycle IoC/DI/ServiceLocator, etc…

Managing interactions data storage, shared data, message brokering, etc…

Problems – Module/Feature level

You have plenty of ‘tools’ and ‘patterns’ that helps you implementing your solution:

• Layered applications

• Implementation patterns (MVC, MVVM, …)

• Reuse services

ServiceLocator – Abstract Factoriesmetacode

Eng. Giorgetti Alessandro

demo

MusicStore (SL 4 version)an example of those techniques in action

Eng. Giorgetti Alessandro

demo

MusicStore (SL 4 version)some indepths

Inspired by this workshop I’ve started a series of articles on my blog you can check to dig into some of the arguments I proposed here:

Silverlight, MVVM … and IoChttp://www.primordialcode.com/blog/post/silverlight-mvvm-ioc-part-1http://www.primordialcode.com/blog/post/silverlight-mvvm-ioc-part-2

Silverlight Navigation Framework … and IoChttp://www.primordialcode.com/blog/post/silverlight-navigation-framework-resolve-pages-ioc-container

More to come…

Eng. Giorgetti Alessandro

Questions ? (and maybe … answers)