separation-of-concerns

To separate concerns in React components, extract data fetching into dedicated hooks or services, move business logic into pure functions, and build presentational components that render from props. A container then composes these layers and manages loading and error states.

The best way to refactor a monolithic component is enforcing the separation of concerns pattern. Move data fetching into a data hook, extract transformations into a formatter as pure functions, build a presentational card, and use a container to compose them.

Mixing data fetching, business logic, and presentation creates untestable components because dependencies are tightly coupled within a single render cycle. Separating them into hooks, pure functions, and presentational components isolates logic for direct testing.

Yes, you can use the container pattern across React-like frameworks to manage loading and error states. The container acts as the composition layer connecting the data, logic, and presentation layers, handling state transitions before rendering the presentational UI.

You need to separate concerns into hooks, pure functions, and presentational components when a UI component simultaneously fetches data, performs transformations, and renders markup. This separation ensures the data layer, logic layer, and presentation layer remain independently maintainable.

Using pure functions for business logic in frontend architecture limits direct state mutation, requiring all data transformations to return new values. This approach demands a container component to explicitly handle side effects and pass results as props to the presentation layer.