What is the difference between Factory and Strategy patterns?
The Factory pattern centralizes object creation, hiding the logic of instantiation and returning new objects from a given interface. Meanwhile, the Strategy pattern allows for algorithm interchangeability at runtime, providing different implementations of a common interface, which can be used by the client code.
Delving Deeper: Factory and Strategy Patterns
Strategic Factories
While Factory is for object creation and Strategy is for algorithm selection, they can effectively work together to deliver flexible designs. A RendererFactory
might create a HighQualityRenderer
or a PerformanceRenderer
based on the strategy implemented. The best of both worlds!
Dynamic Duos
Factories are not just assembly lines for object creation—they can be strategic! A ConnectionPoolFactory
could employ strategies like CachingStrategy
, LoadBalancingStrategy
or FailoverStrategy
. Each strategy can adapt to factors like system load and network conditions.
Interface-Leveraging Patterns
Both Factory and Strategy patterns target interfaces rather than concrete classes. Factories generate concrete instances of a common interface, and strategies use this interface to interchange algorithms. This reduces dependencies and enhances maintainability.
Practical Use Cases
In GUI Development: A WidgetFactory
creates Button
, Checkbox
, or other widgets while a LayoutStrategy
organizes them for different UX requirements.
For Payment Processing: Different PaymentProcessor
instances created by a Factory can use different SecurityStrategy
instances at runtime to handle encryption and data protection.
The Power of Polymorphism
Adaptive Factories
Abstract Factory, with its ability to create families of objects, can use different strategies to adapt object creation to different environments. Think WindowsButtonCreationFactory
and LinuxButtonCreationFactory
for platform-specific UI components.
Strategy Pattern's Flexibility
The Strategy pattern encapsulates behavior, offering interchangeability that isn't available with static methods. By swapping out strategies at runtime without changing client code, adaptability is enhanced. Especially valuable when the system's behavior must change in real time.
Evolving with Requirements
Both Factory and Strategy patterns help you anticipate changes, through modular design. As requirements change, extend factories for new object types and add new strategies without rewriting existing code.
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