Architecting Silverlight Applications

Shawn Wildermuth
shawn@agilitrain.com
http://agilitrain.com
C# MVP, MCSD, INETA Speaker
Silverlight Insider, CSD Insider, Data Insider
Book Author
Pragmatic ADO.NET
MCTS Training Kit (Exam 536)
MCPD Training Kits (Exams 547, 548 & 549)
Windows Phonebook (Upcoming)
Silverlight Architecture (Upcoming)
Silverlight Tour (www.silverlight-tour.com)
Who Am I?

Tight Coupling
Adds Complexity
Simple Changes Cascade
Difficult to Test
Difficult to Develop Large Applications
The Problem

Loose Coupling
Layers are Individually Responsible
Established Patterns
Lessens the Need to Reinvent Architecture
Separation of Concerns

Model-View-Controller
Model-View-Presenter
Model-View-ViewModel
Patterns

XAML is Declarative
Allows for Code-less Views
Older Patterns Don’t Fit
Patterns (2)

Patterns Work for You!
Benefit is common solution to a problem
No solution is perfect
Using Patterns does not make you an architect
Religiosity of a pattern isn’t helpful
The Caveat

Patterns Aren’t Dogma!

Model-View-ViewModel
View
ViewModel
Model

Silverlight
Model-View-ViewModel (2)
XAML
View
C#/VB
ViewModel
Model
Internet
Server
C#/VB
Services

Typically One-to-One ViewModel to View
Not uncommon to have 1..n ViewModel/Views
Single Model is also common
Responsibilities
Model Should Handle CRUD (or Services)
ViewModel Should Expose a Bindable Surface
View Should Format Data as Necessary
Mode-View-ViewModel (3)

Planning on MVVM
Build in Tiers
Plan for Testing
Building the MVVM

The ViewModel
Expose API that the View Needs
Use the Model to Provide the Data
Building the MVVM (4)

The View
Use as Much XAML as Possible
Don’t Write Code to Rebind Data
Perfect View is Code-less
In Blend Behaviors and Element Binding Help
No Such Thing as a Perfect View
Building the MVVM (6)

Demo – Building MVVM

MVVM is Still Growing
Some Frameworks Support it (e.g. Prism)
Philosophy of Specifics is not settled
View-Centric
ViewModel-Centric
Marriage/Mediator
No Completely Right/Wrong Way to Implement It
Patterns Only Good If They Help
Evolving Pattern

The Problems
Monolithic Application

The Problem (2)
Large Projects
Why should you build everything?
Slows down development
Leads to bleed over

The Problem (3)
Versioning
One .xap: Atomic Versioning
Complex Apps Need Better Version Story

Composite Applications
Composite Applications

Not just MVVM or DI
Separate Notions of FX
Core
Modules
Services
Separating Concerns

Frameworks Help
Laurent Bugnion’s Light MVVM
http://www.galasoft.ch/mvvm/getstarted/
Nikhilk Kothari’s FX Framework
http://projects.nikhilk.net/SilverlightFX
Michael Sync’s Silverlight MVVM Toolkit
http://silverlightmvvm.codeplex.com/
Microsoft’s Prism and MEF
http://compositewpf.codeplex.com/
http://mef.codeplex.com/
Caliburn and Caliburn Micro
http://caliburn.codeplex.com/
Frameworks

Links:
My Blog:
http://wildermuth.com
Presentation and Code Available There
Silverlight Tour:
http://silverlight-tour.comn@agilitrain.com
Questions?

Architecting Silverlight Applications

by Shawn Wildermuth

Accessibility

Categories

Upload Details

Usage Rights

Statistics

Architecting Silverlight Applications Presentation Transcript