Dependency Injection - Types

Types

Martin Fowler identifies three ways in which an object can get a reference to an external module, according to the pattern used to provide the dependency:

  • Type 1 or interface injection, in which the exported module provides an interface that its users must implement in order to get the dependencies at runtime.
  • Type 2 or setter injection, in which the dependent module exposes a setter method that the framework uses to inject the dependency.
  • Type 3 or constructor injection, in which the dependencies are provided through the class constructor.

It is possible for other frameworks to have other types of injection, beyond those presented above.

Read more about this topic:  Dependency Injection

Famous quotes containing the word types:

    The bourgeoisie loves so-called “positive” types and novels with happy endings since they lull one into thinking that it is fine to simultaneously acquire capital and maintain one’s innocence, to be a beast and still be happy.
    Anton Pavlovich Chekhov (1860–1904)

    He’s one of those know-it-all types that, if you flatter the wig off him, he chatter like a goony bird at mating time.
    —Michael Blankfort. Lewis Milestone. Johnson (Reginald Gardner)

    The wider the range of possibilities we offer children, the more intense will be their motivations and the richer their experiences. We must widen the range of topics and goals, the types of situations we offer and their degree of structure, the kinds and combinations of resources and materials, and the possible interactions with things, peers, and adults.
    Loris Malaguzzi (1920–1994)