Archive for the ‘Architecture’ Category

Distributed WPF Application

I’ve been going over some ideas (not my own ideas of course) that have been focused around distributed loose-coupled message driven systems, WPF XBAP portals, enterprise architecture, and domain driven design. I’m hoping to post the outline of the ideas as a means to aggregate the ideas in one place, which will hopefully help my and others understanding.

My additional requirements of to be aware of the common symptoms found in system design. From Principles, Patterns, and Practices [Martin],
The symptoms are:

  • Rigidity: The design is difficult to change.
  • Fragility: The design is easy to break.
  • Immobility: The design is difficult to reuse.
  • Viscosity: It is difficult to do the right thing.
  • Needless complexity: Overdesign.
  • Needless repetition: Mouse abuse. [copy/paste programming]
  • Opacity: Disorganized expression.

In addition, I was looking to follow the SOLID principles of programming.
As detailed in Principles, Patterns, and Practices [Martin],

  • Single-Responsibility Principle (SRP): A class should have only one reason to change.
  • Open/Closed Principle (OCP): Software entities (classes, modules, functions, etc.) should be open for extension but closed for modification.
  • Liskov Substitution Principle: Subtypes must be substitutable for their base types.
  • Interface Segregation Principle: Clients should not be forced to depend on methods they do not use.
  • Dependency-Inversion (DI) Principle: High-level modules should not depend on low-level modules. Both should depend on abstractions. Abstractions should not depend upon details. Details should depend upon abstractions.

See Unlce Bob’s Principles of Object Oriented Programming Article for more detail (or his PPP book).

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