I'm using the slices feature of Redux Toolkit. As you may know, one slice returns an action for every created reducer.
I want to use the redux-promise-middleware library, which for a given ACTION_TYPE, it creates three possible new actions: ACTION_TYPE_FETCHING, ACTION_TYPE_FULFILLED, and ACTION_TYPE_REJECTED. How do I handle this from the point of view of the slices?
You'd need to add the expected action types to the extraReducers section of createSlice, like:
// could use a predefined action constant if desired:
const actionFetching = "ACTION_TYPE_FETCHING"
const usersSlice = createSlice({
name: "users",
initialState,
reducers: {
// specific case reducers here
},
extraReducers: {
// could use computed key syntax with a separate type constant
[actionFetching ]: (state, action) => {}
// or the actual field name directly matching the type string
ACTION_TYPE_FULFILLED: (state, action) => {}
}
})
Related
I'm learning about RTK Query and really confused. I'd be happy if someone could point me towards the right direction. My question is how one can manipulate the state of the application store the same way as it is done when using createAsyncThunk and setting up extraReducers.
export const asyncApiCall = createAsyncThunk("api/get_data", async (data) => {
const config = {
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
}
};
const res = await axios.get( "http://apiserver/path_to_api",data,config );
return res['data']
} )
export const mySlice = createSlice({
name:"mySliceName",
initialState:{
data: [],
loadInProgress: false,
loadError: null,
extraData: {
// something derived based on data received from the api
}
},
extraReducers: {
[asyncApiCall .pending]: (state) => {
state.loadInProgress = true;
},
[asyncApiCall .fulfilled]: (state,action) => {
state.loadInProgress = false;
state.data = action.payload;
state.extraData = someUtilFunc(state.data)
},
[asyncApiCall.rejected]: (state) => {
state.loadInProgress = false;
state.loadError= true;
},
}
})
Now I'm replacing it with RTK Query. My current understanding is that RTK Query automatically generates hooks for exposing data received from the api and all the query-related info like if it's pending, if an error occurred etc.
import { createApi, fetchBaseQuery } from '#reduxjs/toolkit/query/react'
export const apiSlice = createApi({
reducerPath: 'api',
baseQuery: fetchBaseQuery({ baseUrl: '/api' }),
endpoints: builder => ({
getData: builder.query({
query: () => '/get_data'
}),
setData: builder.mutation({
query: info => ({
url: '/set_data',
method: 'POST',
body: info
})
})
})
})
export const { useSendDataMutation, useGetDataQuery } = apiSlice
If I want to store some additional data that may be affected by the api calls should I create another slice that will somehow interact with the apiSlice, or is it possible to incorporate everything in this existing code? I'm sorry for possible naivety of this question.
The short answer is that RTK Query is focused on purely caching data fetched from the server. So, by default, it stores exactly what came back in an API call response, and that's it.
There are caveats to this: you can use transformResponse to modify the data that came back and rearrange it before the data gets stored in the cache slice, and you can use updateQueryData to manually modify the cached data from other parts of the app.
The other thing to note is that RTK Query is built on top of standard Redux patterns: thunks and dispatched actions. Every time an API call returns, a fulfilled action gets dispatched containing the data. That means you can also apply another suggested Redux pattern: listening for that action in other reducers and updating more than one slice of state in response to the same action.
So, you've got three main options here:
If the "extra data" is derived solely from the server response values, you could use transformResponse and return something like {originalData, derivedData}
You could just keep the original data in the cache as usual, but use memoized selector functions to derive the extra values as needed
If you might need to update the extra values, then it's probably worth looking at listening to a query fulfilled action in another slice and doing something with it, like this silly example:
import { api } from "./api";
const someExtraDataSlice = createSlice({
name: "extraData",
initialState,
reducers: {/* some reducers here maybe? */},
extraReducers: (builder) => {
builder.addMatcher(api.endpoints.getPokemon.matchFulfilled, (state, action) => {
// pretend this field and this payload data exist for sake of example
state.lastPokemonReceived = action.payload.name;
}
}
})
I'm trying to learn Redux, and i encountered this code:
reducers: {
loginStart: (state) => {
//...
},
loginSuccess: (state, action) => {
//...
},
loginFailure: (state) => {
//...
},
logout: (state) => {
//...
},
},
});
export const { loginStart, loginSuccess, loginFailure, logout } = userSlice.actions;
export default userSlice.reducer;
I can't understand well what are .actions, Slice, .reducer or reducers from different web sources.
So kindly can any expert in Redux here explain in a simplified way what are theses and their roles?
Every state of your app (which is global) lives in an object tree stored in a single store.
Actions are simply JavaScript objects that have a type with a payload of data illustrating exactly what is happening. what they do? they are the only way to manage our state tree. pay attention: no state has been mutated so far.
Reducers are just responses to our corresponding called action to perform on our immutable state and thus returning a new state. optionally you might also want to check Array.reduce() method to better understand reducers.
What is slice then? as it comes with redux-toolkit, slice contains all the reducer logics and actions for a single feature.
it auto generates your action creators and types which you have to define them as constants before redux-toolkit. check createSlice for the full explanation.
In your example the object called reducers goes into your createSlice with also an initial state and a name.
Based on all that being said, this is your final example of your question:
const initialState = {}
const authSlice = createSlice({
name: 'authentication',
initialState,
reducers: {
loginStart: (state) => {
//...
},
loginSuccess: (state, action) => {
//...
},
loginFailure: (state) => {
//...
},
logout: (state) => {
//...
},
},
})
export const { increment, decrement, incrementByAmount } = counterSlice.actions
export default counterSlice.reducer
I have Redux Toolkit - slice, entityAdapter
How i can remove messages for one channal by channel ID?
const messagesAdapter = createEntityAdapter();
const messages = createSlice({
name: 'messages',
initialState: messagesAdapter.getInitialState(),
reducers: {
addMessage: messagesAdapter.addOne,
},
extraReducers: {
[channels.actions.removeChannel]: (state, action) => {
const idCahnnel = action.payload;
const idsForRemove = // how i can get ids here? if i have idCahannel only
// message look like { id: 1, idChannel: 2, nickname: 'nickname', text: 'sometext' }
// i cannot filter state.entity because state is a Proxy here
messagesAdapter.removeMany(state, idsForRemove);
},
},
});
You can do operations against the existing state and its nested fields like state.entities. Yes, the "draft state" has been wrapped in a Proxy, but you can interact with the values as if it were still a plain JS object like normal.
See the Redux Toolkit docs page on Writing Reducers with Immer for instructions on how to correctly work with Immer's draft state values.
How can I get the full state from the extraReduces section?
createSlice({
name: 'foos',
initialState: {
foos: [],
},
reducers: {},
extraReducers: builder => {
builder.addCase(
barAction,
(state, action) => {
const barId = action.payload.id; // barAction handler, the payload is the bar's id
const bar = ??? // getStore().bars[barId]
state.foo[bar.fooId].baz = true;
}
);
},
});
I want to manipulate the Foo slice from Bar action. But the Bar action payload is just the id of the Bar entity.
How can I retrieve the Bar entity from the Foo slice if I only have the Bar ID? Is there any way to get the full store?
Redux slice reducers only have access to their own slice of the state, by definition.
However, we do encourage multiple reducers responding to the same dispatched action.
Hey fellow programmers,
Been having fun learning react-redux lately, but I do have one question that bothers me.
My understanding is that, by using createAsyncThunk it will automatically generates action type constants. (pending, fulfilled, and rejected)
What I wanted to know is that is there any way to manually dispatch action type during createAsyncthunk , so that we can have more flexibility in our code.
import { createAsyncThunk, createSlice } from '#reduxjs/toolkit'
import { userAPI } from './userAPI'
// First, create the thunk
const fetchUserById = createAsyncThunk(
'users/fetchByIdStatus',
async (userId, thunkAPI) => {
const response = await userAPI.fetchById(userId).then(
...
dispatch(fulfilled) // is this possible ?
).catch(
dispatch(rejected) // is this possible ?
)
return response.data
}
)
// Then, handle actions in your reducers:
const usersSlice = createSlice({
name: 'users',
...,
extraReducers: {
// Add reducers for additional action types here, and handle loading state as needed
[fetchUserById.fulfilled]: (state, action) => {
// Add user to the state array
state.entities.push(action.payload)
}
}
})
// Later, dispatch the thunk as needed in the app
dispatch(fetchUserById(123))
The point of createAsyncThunk is that it generates those action types, _and dispatches them for you automatically. You definitely do not need to dispatch(fulfilled()) yourself, because that's what createAsyncThunk does for you - you just need to return a promise that either resolves or reject, and it dispatches the fulfilled/rejected action types based on that.
You do get access to thunkAPI.dispatch, so you can dispatch other actions if necessary, but you don't need to worry about the fulfilled/rejected actions yourself.