Fun with ASP.NET MVC 3,MEF and NuGet

Pure application LEGO

Maarten BalliauwAZUG / VISUG

@maartenballiauwhttp://blog.maartenballiauw.be

Who am I?

• Maarten Balliauw• Antwerp, Belgium• www.realdolmen.com • Focus on web– ASP.NET, ASP.NET MVC, PHP, Azure, …–MVP ASP.NET

• http://blog.maartenballiauw.be • @maartenballiauw

Me, looking intelligent with glasses

Agenda

• Technologies & techniques used– ASP.NET MVC 3–Managed Extensibility Framework (MEF)– NuGet

• Creating application components• Building an application• Conclusion• Further information• Q&A

ASP.NET MVC 3

• All the new stuff:– Razor view engine– Global Action Filters– Unobtrusive Ajax & Client Validation– Better Visual Studio tooling

• And a very interesting one for doing LEGO development:– Better support for Dependency Injection

var partA =new PartA(new PartB())

Dependency Injection?

Part A

I need a “Part B” !

Me on a typicalwork day

Coming up!

Container

Dependency Injection?

Part A

I need a “Part B” !

Part B

Let me see...There

you go!

What about ASP.NET MVC 3?

• ASP.NET MVC 3 uses DependencyResolver

• : IDependencyResolver–GetService()–GetServices()

• Register it on application start

What about ASP.NET MVC 3?

• ASP.NET MVC will / can query the IDependencyResolver for– Controllers– View engines & view pages– Filters– Model validators– Model metadata

• Check Brad Wilson’s blog for examples on all of these– http://bradwilson.typepad.com/blog/2010/07/service-

location-pt1-introduction.html

– Value providers– Model binders– Controller activator– View page activator

demo in ASP.NET MVC 3

DEPENDENCY INJECTION

Managed ExtensibilityFramework (MEF)

• Cool as ICE: Import, Compose, Export

MEF catalogHomeController

[Import]IRule rule;

SomeRuleImpl

[Export(typeof(IRule)]

MEF container

Let me see...There

you go!

MEF in ASP.NET MVC 3

• Build an IDependencyResolver–based on MEF container

• Use –has a built-in IDependencyResolver–has a “Convention” model– is available on NuGet–mefcontrib.codeplex.com

A brief NuGet introduction...

• Package management system for .NET• Simplifies incorporating 3rd party libraries• Developer focused• Free, open source

• Use packages from the official feed• Publish your own packages• Create & use your own feed

demoand finding it on NuGet

USING MEFCONTRIB

MefContrib.MVC3

• Optional addition for • Adds some things to your application:–AppStart code that does the wiring–A CompositionDependencyResolver–Will check all assemblies in /bin–Will export everything : IController by

convention

Conventions based modelpublic class MvcApplicationRegistry : PartRegistry { public MvcApplicationRegistry() { Scan(x => { x.Assembly(Assembly.GetExecutingAssembly()); x.Directory(AppDomain.CurrentDomain.BaseDirectory + "\bin"); });

Part() .ForTypesAssignableFrom<IController>() .MakeNonShared() .ExportTypeAs<IController>() .ExportType() .Imports( // ... ); }}

This all makes me think...

• Package company components using NuGet?• Distribute them in a custom feed?• Use ASP.NET MVC 3?• Wire everything with MEF & MefContrib?• Pure application Lego!

Me, thinking

demoapplication components

CREATING

What’s next?

• Building it– MSBuild (or whatever! Nuget.exe is all that matters)

• Hosting it– Create a NuGet server– Drop everything in a folder– Use a NaaS solution: www.myget.org

• Using it– Reference the feed– Download & install components needed– Assemble using MEF (or another IoC)

Install-Package NuGet.Server

A quick commercial plug

• Create your own NuGet feed• Packages from official feed• Uploaded/pushed packages• No need to setup & maintain your own

NuGet Server• Free! www.myget.org

demoa private NuGet feed

CREATING IT THE LAZY WAY

Let’s see if we can build this...TPS Reports Cover Sheet Generator (ASP.NET

MVC 3)

Domain layer

Domain.TpsReports

Authentication

AccountController

Contracts

And their implementations...

Theme

Default theme

Packagedas .nupkg

Wiredwith MEF

demoCover Sheet Generator

BUILDING AN APPLICATION

Conclusion

• You can build an app like a Lego set– Requires “bricks” (NuGet packages)– Requires “glue” (MEF / MefContrib / IoC)

• Requires you to think in terms of components– Structure is key!

• Not a best-practice architecture– Just something we toyed with on a project– Proved to work (for the customer)

Further information

• On the Internet:–www.nuget.org–www.myget.org –mefcontrib.codeplex.com

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Me, having a question

http://blog.maartenballiauw.be @maartenballiauw