The Strategy pattern replaces growing conditionals with interchangeable behavior objects that are easier to extend and test.
A common code smell
A method that switches on type, provider, status, or format often starts harmlessly. Then the project grows. Each new case adds another branch. Tests become long because every branch shares setup. The Strategy pattern moves each branch into a class that implements the same interface.
Designing the strategy contract
The interface should describe the behavior the workflow needs. For shipping, it might be calculate(Order $order): Money. For content rendering, it might be render(Post $post): string. Keep the contract small. If one strategy cannot implement the method honestly, the interface is probably too broad.
Selecting a strategy
A resolver chooses the correct strategy based on input. It might use an array keyed by provider name, a database setting, or a configuration file. The resolver should fail clearly when a strategy is missing. Silent fallback behavior can hide configuration mistakes and create production bugs.
Testing benefits
Each strategy can be tested with focused examples. The main workflow can be tested with a fake strategy to prove orchestration. The resolver can be tested separately. This creates a clean test pyramid around behavior that used to live in one complicated conditional.
Strategy and performance
Strategy objects are usually lightweight. The performance cost of an extra object is rarely important compared with the clarity gained. The bigger performance risk is strategies that do unexpected database or network work. Keep expensive work visible and consider caching or batching when strategies are used in loops.
Laravel implementation
Bind strategies in the container or create them through a small factory. For simple cases, an array of class names in config is enough. The service container can instantiate each class with its dependencies. This keeps the workflow independent of concrete implementations.
Related patterns
Strategy often appears beside Factory, because something must choose the strategy. It also supports the Open Closed Principle because adding behavior means adding a class instead of modifying a central method.
Internal reading path
This article is part of a connected OOP and design patterns series. Continue with these related guides:
- Open Closed Principle With PHP Strategies
- Composition Over Inheritance in Modern PHP
- Factory Pattern in PHP: Creating Objects Without Spreading Construction Logic
Practical checklist
- Name the responsibility before choosing a pattern.
- Prefer small contracts where behavior varies or external services are involved.
- Keep controllers at the edge and move workflows into named application code.
- Add tests around the behavior that is most likely to change.
- Use patterns to reduce coupling, not to make simple code look advanced.