Persisting the State to the Local Storage

reactjs_persisting_state_to_local_storage.js

// See: https://egghead.io/lessons/javascript-redux-persisting-the-state-to-the-local-storage

const loadState = () => {
  try {
    const serializedState = localStorage.getItem('state');
    if (serializedState === null) {
      return undefined;
    }
    return JSON.parse(serializedState);
  } catch (err) {
    return undefined;
  }
}
const saveState = (state) => {
  try {
    const serializedState = JSON.stringify(state);
    localStorage.setItem('state', serializedState);
  } catch (err) {
    // Ignore write errors.
  }
}

const persistedState = loadState();
const store = createStore(
  todoApp,
  persistedState
);

store.subscribe(() => {
  saveState({
    todos: store.getState().todos
  });
});