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Accessing Redux state in an action creator?

javascript
redux-thunk
async-requests
action-creators
Alex KataevbyAlex Kataev·Jan 27, 2025
TLDR

Redux Thunk is your key to access the Redux state within an action creator. It allows action creators to return functions instead of actions, providing a path to the state through the getState method.

Below is a simple illustration:

const accessStateAction = () => (dispatch, getState) => { const state = getState(); // Who can resist the allure of state? dispatch({ type: 'ACTION_TYPE', payload: state.someData }); // Payload away! };

To interact with the state, just dispatch accessStateAction.

To allow state reads in action creators, Redux Thunk helps in forming a robust solution. This pattern, recommended by Redux influencers like Dan Abramov and Mark Erikson, can aid in constructing safer and more maintainable code.

When considering server rendering, avoid directly accessing the Redux store in action creators, as it may lead to discrepancies. On the contrary, using Thunk's getState ensures consistency across the board.

Animate your action creators with a minimalistic spirit. Include only what's necessary to describe your action - doing so can markedly simplify your actions and shield your code from unnecessary complexity.

For running your state-related tasks and side effects, middleware like Redux Thunk, or Redux-Saga for more intricate orchestration, can be beneficial.

Finally, establishing connect ties between your Redux store's state and actions to your React components can be enabled with mapStateToProps and mapDispatchToProps from react-redux.

Access Redux state: Practical guidelines

Accessing specific state slices with thunks

Redux Thunk equips action creators with the ability to access specific sections of the state, clearly demarcating the boundary between data and UI layers:

  • Gather related data: Extract connected pieces of state for an action with selectors.
  • Refactor dependencies: Use withExtraArgument in Thunk actions for easier testing and dependency injection.
  • Avoid the store import: Eschew store import in action creators to ensure compatibility with server rendering and simplified testing.

Structuring for asynchronous requests

When managing asynchronous requests, granular actions yield more clarity:

  1. Dispatch REQUEST_LOAD to display loading state.
  2. On successful data fetch, trigger the SUCCESS action.
  3. Handle any failures using a FAIL action.

Keeping your actions sharp and clear minimizes confusions, especially when you need to manage loading indicators or error states.

Simplifying action creation

Avoid stuffing your action creator with logic. Remember:

  • Single responsibility: Let the action creator focus on one thing at a time.
  • Divide the async logic: Keep the concerns separated by dispatching based on the request status.
  • Think du jour: For complex actions, adopting structures like redux-tiles or incorporating multiple actions within a thunk can help.