I use redux's combineReducers() helper function to combine two reducers like so:
const rootReducer = combineReducers({
user: userReducer,
accounts: accountsReducer
})
I know each reducer can only modify a slice of the store it's assigned to, "user" and "accounts" in this case.
How can i modify the "user" part of my store from my accounts reducer?
You can't.
You can either listen to the same action in both reducers, or if you need to update the user state based on the update to the accounts' state, then you can use Redux thunks - https://github.com/gaearon/redux-thunk
const action = () => (dispatch, getState) => {
// dispatch action that accounts reducer listens to
dispatch({
type: 'SOME_ACTION'
})
// get the new accounts state
let { accounts } = getState()
// dispatch action that user reducer listens to, passing the new accounts state
dispatch({
type: 'ANOTHER_ACTION',
payload: {
accounts
}
})
}
// call with
dispatch(action())