How to refactor redux + thunk actions/constants - redux

Question

In my react/redux/thunk application I use actions like:
function catsRequested() {
return {
type: CATS_REQUESTED,
payload: {},
};
}
function catsReceived(landings) {
return {
type: CATS_RECEIVED,
payload: landings,
};
}
function catsFailed(error) {
return {
type: CATS_FAILED,
payload: { error },
};
}
export const fetchCats = () => ((dispatch, getState) => {
dispatch(catsRequested());
return catsAPI.loadCats()
.then((cats) => {
dispatch(catsReceived(cats));
}, (e) => {
dispatch(catsFailed(e.message));
});
});
To deal with some data (simplified). Everything works but i have a lot of code for every data entity (and constants too).
I mean same functions for dogs, tigers, birds etc...
I see there are similar requested/received/failed action/constant for every entity.
What is right way to minify code in terms of redux-thunk?

Answer 1

You can keep your code DRY by creating a types and a thunk creators:
Type:
const createTypes = (type) => ({
request: `${type}_REQUESTED`,
received: `${type}_RECEIVED`,
failed: `${type}_FAILED`,
});
Thunk:
const thunkCreator = (apiCall, callTypes) => ((dispatch, getState) => {
dispatch({ type: callTypes.request });
return apiCall
.then((payload) => {
dispatch({ type: callTypes.received, payload }));
}, (e) => {
dispatch({ type: callTypes.failed, payload: e.message }));
});
});
Now you can create a fetch method with 2 lines of code:
export const fetchCatsTypes = createTypes('CATS'); // create and export the constants
export const fetchCats = (catsAPI.loadCats, fetchCatsTypes); // create and export the thunk
export const fetchDogsTypes = createTypes('DOGS'); // create and export the constants
export const fetchDogs = (dogsAPI.loadDogs, fetchDogsTypes ); // create and export the thunk
Note: you'll also use the types constant (fetchDogsTypes) in the reducers.