Elegant
selectors

Selectors

Selectors in state management are pure functions that extract and compute derived data from the application’s state.

Key aspects of selectors include:

Best Practice

Based on the search results and best practices in state management, here are key recommendations for working with selectors or views:

  1. Keep Selectors Simple and Focused
    • Create selectors that target specific pieces of state
    • Avoid complex logic within selectors
    • Use composition to build more complex selectors from simpler ones
  2. Use Memoization for Performance
    • Utilize libraries like Reselect to create memoized selectors
    • This optimizes performance by caching results and avoiding unnecessary recalculations
  3. Centralize Selector Definitions
    • Define reusable selectors in a central location (e.g., in slice files or a dedicated selectors.js)
    • This improves maintainability and makes it easier to update state structure
  4. Decouple Components from State Shape
    • Use selectors to abstract away the details of state structure from components
    • This makes it easier to refactor state without affecting components
  5. Avoid Direct State Access in Components
    • Instead of accessing state directly, use selectors in useSelector hooks
    • This promotes better encapsulation and reusability
  6. Compose Selectors for Complex Data Transformations
    • Build complex selectors by combining simpler ones
    • This improves readability and maintainability
  7. Use Selectors for Derived Data
    • Calculate derived data in selectors rather than storing it in the state
    • This keeps the state minimal and avoids data duplication
  8. Test Selectors Thoroughly
    • Write unit tests for selectors to ensure they work correctly
    • This is especially important for complex selectors
  9. Consider Performance Implications
    • Be mindful of selector complexity and frequency of updates
    • Use memoization and other optimization techniques for expensive computations
  10. Use Typed Selectors (for TypeScript projects)
    • Define proper types for selectors to improve type safety and developer experience
  11. Avoid unnecessary re-renders
    • Ensure that your selectors only return new references when the underlying data has actually changed. This prevents unnecessary component re-renders.

By following these practices, you can create more maintainable, performant, and scalable state management solutions in your applications.

References