Reviewing Facade in the GoF book and the link in another answer to Martin Fowler’s Gateway, it appears that their focus is in opposite directions. Facade provides a simple uniform view of complex internals to (one or more) external clients; Gateway provides a simple uniform view of external resources to the internals of an application. … Read more
The strategy pattern allows you to change the implementation of something used at runtime. The decorator pattern allows you augment (or add to) existing functionality with additional functionality at run time. The key difference is in the change vs augment In one of the questions you linked to it also points out that with the … Read more
A Composite is a pattern that is useful anytime you may need to selectively treat a group of objects that are part of a hierarchy as “the same” when they are in fact different. Typically the examples used talk in terms of treating leaves and nodes the same, but the pattern can also be extended … Read more
Design patterns are supposed to provide a structure in which problems can be solved. When solving a real problem, you have to consider many tiny variations of a solution to that problem to see whether any fits a design pattern. In particular, you will probably need to generalise your problem, or its solution, in order … Read more
CQRS is not a pattern that encompasses the whole application. It is a concept that builds on Domain Driven Design (DDD). And an important strategic concept of DDD is the so-called Bounded Context. In a typical application there are multiple bounded contexts, any of which can be implemented the way it makes sense. For instance … Read more
The prototype pattern has some benefits, for example: It eliminates the (potentially expensive) overhead of initializing an object It simplifies and can optimize the use case where multiple objects of the same type will have mostly the same data For example, say your program uses objects that are created from data parsed from mostley unchanging … Read more
from Decorator pattern at wikipedia The decorator pattern can be used to make it possible to extend (decorate) the functionality of a certain object at runtime. The whole point of decorator pattern is to dynamically add additional behaviour/functionality, which is of course not possible at design time. from the same article: The decorator pattern is … Read more
Did I “get” it? Sorry to say, not quite. The goal of Context Object is not to pass lots of parameters to methods implicitly, as a means of by-passing strong typing and encapsulation. The goal is to store scoped data in a general, but managed way, independent of protocols and presentation technology. Data stored within … Read more
These patterns and best practices are often bound to a specific platform/language, so they are the first place to look for them. Exception patterns wiki is a general patterns resource. As an example check the following links for java: Best Practices for Exception Handling 15 Best practices about exception handling Exception-Handling Antipatterns Going through such … Read more
I think you’re not seeing the forest for the trees here. ILog and LogManager are a lightweight façade almost 1:1 equivalent to Apache commons-logging, and do not actually couple your code to the remainder of log4net. <rant> I’ve also found that almost always when someone creates a MyCompanyLogger wrapper around log4net they miss the point … Read more