Dynamically extending responsibilities using Decorator Pattern

Jean Paul

15y25k20100Article

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Gary Guo15y ago
Dynamic Decorator extends functionality of an object without modifying its class or writing decoration code during design time. Here is the link to the article http://www.codeproject.com/KB/architecture/dynamicdecorator.aspx
- Jean Paul15y agoedited
  I had a look at the article. There I found it is method injection mechanism is used. I would like to know whether it is the dot net proxy generating library of 3rd party. Coming back to the point, I used the term dynamic as in the runtime we are determining the need for decoration. In Inheritance the classes are statically binded. In your article too, the proxy creation code is during design time. So you might be referring to term dynamic because due to the injection code. I have referred the code dynamic as it is used in contexts like Static Polymorphism, Dynamic Polymorphism etc. (here method overloading / overriding is used) The main pitfall I found in your code in codeproject is you are referring the method Salary as "Salary". that means it is a string reference not a typed reference. This makes the code tedious to maintain in the long run. I believe injection mechanisms should not be used in the scenario you have given. It should be better in cross cutting concerns like writing to log, sending mail about process etc. rather than dealing with the core cocerns of business logic. The aim of my article was to show the Design Pattern Decorator which says adding responsibilities to object in runtime. That is the reason I purely made it free from any di/aop frameworks like sprint.net, ninject, ent lib policy injection. Hope this would give more clarity. I forgot one thing... Happy Christmas Gary!!