Usage
As modern software engineering depends more on object composition than class inheritance, emphasis shifts away from hard-coding behaviors toward defining a smaller set of basic behaviors that can be composed into more complex ones. Hard-coding behaviors are inflexible because they require overriding or re-implementing the whole thing in order to change parts of the design. Additionally, hard-coding does not promote reuse and is hard to keep track of errors. For these reasons, creational patterns are more useful than hard-coding behaviors. Creational patterns make design become more flexible. They provide different ways (patterns) to remove explicit references in the concrete classes from the code that needs to instantiate them. In other words, they create independency for objects and classes.
Consider applying creational patterns when:
- A system should be independent of how its objects and products are created.
- A set of related objects is designed to be used together.
- Hiding the implementations of a class library of product, revealing only their interfaces.
- Constructing different representation of independent complex objects.
- A class want its subclass to implement the object it creates.
- The class instantiations are specified at run-time.
- There must be a single instance and client can access this instance at all times.
- Instance should be extensible without being modified.
Read more about this topic: Creational Pattern
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