Builder

• A separate component for building object
• Either give builder a constructor or return it via a static function
• To make a builder fluent return this in Java or *this in C++
• Different facets of an object can be built with different builders
  working in tandem via a base class

Gamma Categorization

Motivation:

• When piecewise object construction is complicated,
  provide an API to do it succinctly.

General builder

• A modeling class for modeling a realistic object
• A separate class (builder) to create and manage the objects

Fluent Builder

• Fluent interface allow these kind of function call: Object.FunctionA().FunctionB()
  • To make this happened, simply return **this
• The modeling class can have a build function that return a builder
• To force use of builder
  • Make constructor of modeling class private
  • Make builder class friend of modeling class

Groovy-Style Builder

Builder Facets

• Builder Facets splits the scope of the builder into a smaller aspect. For example:
  • Instead of only one builder class for modeling class Person
  • We can have PersonJobBuilder, PersonAddressBuilder together with
    PersonBuilder