Pattern-Oriented Software Architecture For Dummies

Grouping Patterns

The pattern classifications define categories of patterns that are useful to you at different times while building your system. In this section, I introduce two different ways of grouping patterns based on the domain of technology the patterns cover rather than the scope of problems they solve.

As I mention in the discussion of design patterns earlier in this chapter, patterns address and resolve the problems that are left unanswered by other patterns. Sometimes, several patterns can be used together to solve a problem that is much bigger than any of the patterns being used. Patterns work together in these ways, as I tell you in the upcoming section about pattern languages.

Not all the patterns within a collection or a language are meant to be used to solve any given problem. Both groupings contain more patterns than you'll actually use to solve any practical design problem.

Pattern collections

Put any group of items together, and you can call the group a collection. Many of the published sets of patterns out in the world are just that — collections of patterns. They're grouped for convenience. Maybe they fill out a book or were written by the same author.

Patterns in a collection can work together to solve bigger problems, such as when you use both Command and Memento (from Design Patterns: Elements of Reusable Object-Oriented Software) to implement an undo function. ...