next.js mapStateToProps, mapDispatchToProps and getInitialProps - reactjs

Question

i am currently still trying to wrap my head around redux when using next.js and i am not sure what is the best way to use redux with next. I am used to using mapDispatchToProps for my actions and mapStateToProps for my props. After some research i am now using next-redux-wrapper in my _app.js like recommended but now i am fighting with how to best get my props and dispatch my actions. I had look at a few examples and practices and now have a counter component based on one of these examples.
class Counter extends Component {
increment = () => {
const {dispatch} = this.props
dispatch(incrementCount())
}
decrement = () => {
const {dispatch} = this.props
dispatch(decrementCount())
}
reset = () => {
const {dispatch} = this.props
dispatch(resetCount())
}
render () {
const { count } = this.props
return (
<div>
<h1>Count: <span>{count}</span></h1>
<button onClick={this.increment}>+1</button>
<button onClick={this.decrement}>-1</button>
<button onClick={this.reset}>Reset</button>
</div>
)
}
}
function mapStateToProps (state) {
const {count} = state.counter;
return {count};
}
export default connect(mapStateToProps)(Counter)
Most examples i have seen so far do something similar to this or only dispatch actions in getInitialProps. Is there a reason to do it this way and not use mapDispatchToProps?
Cause this work perfectly fine as well:
export default connect(null, {authenticate})(Signin);
Dispatching actions in getIntialProps seems to have some drawback (or i made some mistakes), cause they do not get executed again when the props change. In my user-profile component i get the current user based on a token from the redux store like this:
const Whoami = ({isAuthenticated, user}) => (
<Layout title="Who Am I">
{(isAuthenticated && user && <h3 className="title is-3">You are logged in as <strong className="is-size-2 has-text-primary">{user}</strong>.</h3>) ||
<h3 className="title is-3 has-text-danger ">You are not authenticated.</h3>}
</Layout>
);
Whoami.getInitialProps = async function (ctx) {
initialize(ctx);
const token = ctx.store.getState().auth.token;
if(token) {
const response = await axios.get(`${API}/user`, {headers: {
authorization: token
}});
const user = response.data.user;
return {
user
};
}
}
const mapStateToProps = (state) => (
{isAuthenticated: !!state.auth.token}
);
export default connect(mapStateToProps)(Whoami);
This works perfectly fine for the initial page-load or when navigating there one the client, but when the token expires or i logout the page does not reflect that without reload or navigating there again without my mapStateToProps. But it seems super clunky to split the concern over 2 seperate functions. But i cant find a cleaner way to do it.
Thanks in advance

Answer 1

About mapDispatchToProps:
It is better to use mapDispatchToProps at least because it is easier to test: you can just pass a mock function to your component. With using this.props.dispatch to dispatch some imported actions it can be much harder.
About getInitialProps:
This answer may be helpful:
GetInitialProps: is provided by Next.js and it is NOT always triggered, so be careful with that, it happen when you wrap 1 component inside another. If the parent Component has GetInitialProps, the child's GetInitialProps will never be triggered, see this thread for more info.

Answer 2

I found some answers to my questions after playing around with next a bit more. For pages where the data does not change after intial load, i could get rid of mapStateToProps by rewriting my thunks a bit to return the dispatches and only use getInitialProps like this:
export function fetchShow(id) {
return (dispatch) => {
dispatch({ type: actionTypes.FETCH_SHOW_REQUESTED,id});
// we need to return the fetch so we can await it
return fetch(`http://api.tvmaze.com/shows/${id}`)
.then((response) => {
if (!response.ok) {
throw Error(response.statusText);
}
//dispatch(itemsIsLoading(false));
return response;
})
.then((response) => response.json())
.then((data) => dispatch({type: actionTypes.FETCH_SHOW_SUCEEDED,id, show: data, time: Date.now() }))
.catch(() => dispatch({ type: actionTypes.FETCH_SHOW_ERROR,id }));
};
}
Post.getInitialProps = async function ({store, isServer, pathname, query}) {
const { id } = query;
const {show} = await store.dispatch(fetchShow(id));
return {show};
}
For pages where the data should update upon store changes i am not sure yet. My current idea is to try and write a helper function that will be called from both getInitialProps and mapStateToProps to reduce code duplication but i am not sure yet.