The Facade Pattern (or façade pattern) is a software design pattern commonly used with object-oriented programming. The name is by analogy to an architectural facade. A facade is an object that provides a simplified interface to a larger body of code, such as a class library.
The facade pattern (also spelled façade) is a software-design pattern commonly used in object-oriented programming. Analogous to a facade in architecture, a facade is an object that serves as a front-facing interface masking more complex underlying or structural code. A facade can:
- improve the readability and usability of a software library by masking interaction with more complex components behind a single (and often simplified) API
- provide a context-specific interface to more generic functionality (complete with context-specific input validation)
- serve as a launching point for a broader refactor of monolithic or tightly-coupled systems in favor of more loosely-coupled code
Developers often use the facade design pattern when a system is very complex or difficult to understand because the system has a large number of interdependent classes or because its source code is unavailable. This pattern hides the complexities of the larger system and provides a simpler interface to the client. It typically involves a single wrapper class that contains a set of members required by the client. These members access the system on behalf of the facade client and hide the implementation details.