My reducers like:
const initialState = [
{
fname: null,
lname: false,
}
]
export default function login(state = initialState, action) {
switch (action.type) {
case LOGIN:
console.log("actions")
console.log(action)
console.log("reducers")
return
[{
fname: action.fname,
lname: action.lname,
}]
default:
return state
}
}
Here I am getting action object with fname and lname but this is giving me error saying .. Uncaught Error: Reducer "login" returned undefined handling "LOGIN". To ignore an action, you must explicitly return the previous state.
Why I am getting this error ?
Replace:
return
[
To:
return [
Because first is like return; (js adds ; at the end of line)
or
...
console.log("reducers")
return([{
fname: action.fname,
lname: action.lname,
}])
//example
function getPerson(){
return([{
fname: 'jay',
lname: 'dawg'
}])
}
console.log(getPerson()[0].lname) // "dawg"
For me, it was happening because I forgot to make the action call asynchronous async
export const asyncFetchUser = () => async (dispatch) => {
const response = *await* axios.get('http://localhost:5000/api/current_user');
dispatch({ type: ASYNC_FETCH_USER, auth: response.data });
};
Related
I build an applicant with Redux RTK with createEntity
Two issue that I couldn't found it on the docs
CreateEntity is only return {ids: [], entities: []}? Is possible that return eg: totalPage from the response also?
Cache page only work on the hardcode initialState in createSlice if the pageQuery is same.
First question:
Getting the response from server was
{
users: [{id: 1}, ...]
totalPage: 100
}
I'd like to send totalPage to auto generated hook also.
export const usersAdapter = createEntityAdapter({})
export const initialState = usersAdapter.getInitialState()
export const usersApiSlice = apiSlice.injectEndpoints({
endpoints: (builder) => ({
getUsers: builder.query({
query: (args) => {
return {
url: '/api/users',
method: 'GET',
params: { page: 1, limit: 10 }
}
},
validateStatus: (response, result) => {
return response.status === 200 && !result.isError
},
transformResponse: (responseData) => {
const loadedUsers = responseData?.users.map((user) => user)
console.log("responseData: ", responseData) // <----- return { users: [], totalPage: 100 }. Could we set this totalPage value into Adapter?
return usersAdapter.setAll(initialState, loadedUsers)
},
providesTags: (result, error, arg) => {
if (result?.ids) {
return [
{ type: "User", id: "LIST" },
...result.ids.map((id) => ({ type: "User", id })),
]
} else return [{ type: "User", id: "LIST" }]
},
})
})
})
Use the hook in component
const { data } = useGetUsersQuery("page=1&limit=10");
console.log(data) // { ids: [], entity: [{}, {}] };
// expected return { ids: [], entity: [{}, {}], totalPage: 100}
Second question:
Store the page query in createSlice. The edit page will be remain same after refresh if the page query value same as initialState value.
import { createSlice } from "#reduxjs/toolkit"
const userReducer = createSlice({
name: "user",
initialState: {
query: `page=1&limit=10`,
},
reducers: {
setUserPageQuery: (state, action) => {
const query = action.payload
state.query = query
},
},
})
Page url Flow:
localhost:3000/users > localhost:3000/users/4 > refresh -> data will remain after refresh browser. (query "page=1&limit10" same as createSlice initialState value )
localhost:3000/users > localhost:3000/users/15 > refresh -> data state will gone after refresh browser. (query "page=2&limit10" different from createSlice initialState value )
Appreciate all the reply :)
I've created react app with react-reducer.
I've declared types for actions and in the main Reduce I face an issue:
Can't read property type of undefined
import {ADD_USERS, DELETE_USER, GET_USERS} from '../types'
const initialState = {
users: [
{
id: 1,
name: 'Oksana'
},
{
id: 2,
name: 'Serge'
},
],
loading: true
}
export default function(state = initialState, action){
switch(action.type){
case GET_USERS:
return {
...state,
users: action.payload,
loading: false
}
case ADD_USERS:
const newId = state.users[state.users.length-1] + 1
return {
...state,
users: {
[newId] : {
id: newId,
name: action.name
}
},
loading: false
}
case DELETE_USER :
return {
...state,
users: state.users.filter(i => i.id !== action.id)
}
default: return state
}
}
so here I implement simple get/delete/add methods.
export function getUsers (name) {
return {
type: GET_USERS,
payload: name
}
}
....
and this is actions file
I export all the actions, idk where could I make a mistake
the rest of actions I've not mentioned.
Your switch statement uses action.type, however action is undefined in at least one of the actions you pass to the reducer. Either add a default value to action or add a guard before the switch-statement like so:
export default function(state = initialState, action){
if (!action) {
return state
}
switch(action.type){
case GET_USERS:
return {
...state,
users: action.payload,
loading: false
}
...
As you have a default condition already, adding a default value to action, e.g. action = {} might be the cleaner solution.
If you use Typescript you could also just do the following:
export default function(state = initialState, action){
switch(action?.type){
case GET_USERS:
return {
...state,
users: action.payload,
loading: false
}
...
I'm wondering if there is a pattern that allows you to use action creators inside of other action creators. The modifyMassProperty action creator lets you pass any number of actions which are then iterated over and dispatched accordingly. I would very much like to be able to use this method in the getOrbitalBurn action creator since it would be semantically more appealing than using the dispatch method made available by the thunk three times in a row. I'm confident I must either have missed something, or that I'm guilty of getting tangled up in some sort of anti pattern that I concocted during one of my lesser days.
export const modifyMassProperty = (
...massProperties: MassProperty[]
): ThunkAction<void, AppState, void, Action> => (
dispatch: Dispatch<ScenarioActionTypes>
) =>
massProperties.forEach(massProperty =>
dispatch({
type: MODIFY_MASS_PROPERTY,
payload: massProperty
})
);
export const getOrbitalBurn = (
payload: { primary: string; periapsis: number; apoapsis: number },
applyBurn = true
): ThunkAction<void, AppState, void, Action> => (
dispatch: Dispatch<ScenarioActionTypes>,
getState: any
) => {
const scenario = getState().scenario;
const primary = getObjFromArrByKeyValuePair(
scenario.masses,
'name',
payload.primary
);
const orbit = orbitalInsertion(primary, payload, scenario.g);
if (applyBurn) {
const [spacecraft] = scenario.masses;
dispatch({
type: MODIFY_MASS_PROPERTY,
payload: {
name: spacecraft.name,
key: 'vx',
value: orbit.x
}
});
dispatch({
type: MODIFY_MASS_PROPERTY,
payload: {
name: spacecraft.name,
key: 'vy',
value: orbit.y
}
});
dispatch({
type: MODIFY_MASS_PROPERTY,
payload: {
name: spacecraft.name,
key: 'vz',
value: orbit.z
}
});
}
dispatch({
type: MODIFY_SCENARIO_PROPERTY,
payload: {
key: 'orbitalInsertionV',
value: { x: orbit.x, y: orbit.y, z: orbit.z }
}
});
};
Firstly, I'm working with React Native. I'm getting a data from Firebase and want to write to store (by Redux) quickly. But It doesn't work. You can find my all of codes below:
Function:
async getTumData (uid) {
const {selectedGroupDetail, getSelectedGroupDetail} = this.props;
var yeniGrupDetayi = {};
await firebase.database().ref("/groups/"+uid).once('value').then(
function(snapshot){
yeniGrupDetayi = {...snapshot.val(), uid: uid};
}).catch(e => console.log(e.message));
console.log("FONKSIYON ICERISINDEKI ITEM ==>", yeniGrupDetayi);
this.props.getSelectedGroupDetail(yeniGrupDetayi);
console.log("ACTION'DAN GELEN ITEM ===>", selectedGroupDetail);
}
Action:
export const getSelectedGroupDetail = (yeniGrupDetayi) => {
return {
type: GET_SELECTED_GROUP_DETAIL,
payload: yeniGrupDetayi
}
};
Reducer:
case GET_SELECTED_GROUP_DETAIL:
return { ...state, selectedGroupDetail: action.payload}
Çıktı:
FONKSIYON ICERISINDEKI ITEM ==> {admin: {…}, groupDescription: "Yaygın inancın tersine, Lorem Ipsum rastgele sözcü…erini incelediğinde kesin bir kaynağa ulaşmıştır.", groupName: "İnsan Kaynakları", groupProfilePic: "", members: {…}, …}
ACTION'DAN GELEN ITEM ===> {}
There is a FlatList in my page and I defined a button in renderItem of FlatList. When i click to this button, getTumData() function is working.
When i click to this button first time, selectedGroupDetail is null. Second time, it shows previous data.
How can i write a data to Store quickly and fast?
Thanks,
The thing is:
- You're using both async/await, and then/catch in your code.
- you're calling getSelectedGroupDetail before your async code resolves.
Fast Solution
getTumData = (uid) => {
const {selectedGroupDetail, getSelectedGroupDetail} = this.props;
var yeniGrupDetayi = {};
firebase.database().ref("/groups/"+uid).once('value').then(
(snapshot) => {
yeniGrupDetayi = {...snapshot.val(), uid: uid};
this.props.getSelectedGroupDetail(yeniGrupDetayi);
}).catch(e => console.log(e.message));
};
Better Solution:
1st: use Redux-Thunk middleware.
2nd: Move your Async code into your action creator: I mean this
async getTumData (uid) {
const {selectedGroupDetail, getSelectedGroupDetail} = this.props;
var yeniGrupDetayi = {};
await firebase.database().ref("/groups/"+uid).once('value').then(
function(snapshot){
yeniGrupDetayi = {...snapshot.val(), uid: uid};
}).catch(e => console.log(e.message));
console.log("FONKSIYON ICERISINDEKI ITEM ==>", yeniGrupDetayi);
this.props.getSelectedGroupDetail(yeniGrupDetayi);
console.log("ACTION'DAN GELEN ITEM ===>", selectedGroupDetail);
}
3rd: Your reducer should have another piece of data as an indicator for the time-gap before your selectedGroupDetail resolves:
// reducer initial state:
const INITIAL_STATE = { error: '', loading: false, selectedGroupDetail: null }
4th: Inside your action creator, you should dispatch 3 actions:
ACTION_NAME_START // This should should only set loading to true in your reducer.
ACTION_NAME_SUCCESS // set loading to false, and selectedGroupDetail to the new collection retured
ACTION_NAME_FAIL // in case op failed set error
5th: Your React component, should display a loading indicator (spinner or somthing), and maybe disable FlatList button during the loading state.
// Action creator
export const myAction = () => (dispatch) => {
dispatch({ type: ACTION_NAME_START });
firebase.database().ref("/groups/"+uid).once('value').then(
function(snapshot){
yeniGrupDetayi = {...snapshot.val(), uid: uid};
dispatch({ type: ACTION_NAME_SUCCESS, payload: yeniGrupDetayi });
}).catch(e => {
dispatch({ type: ACTION_NAME_FAIL, payload: e.message });
});
};
// Reducer
const INITIAL_STATE = {
loading: false,
error: '',
data: null,
};
export default (state = INITIAL_STATE, { type, payload }) => {
switch (type) {
case ACTION_NAME_START:
return {
...state,
error: '',
loading: true,
data: null,
};
case ACTION_NAME_SUCCESS:
return {
...state,
error: '',
loading: false,
data: payload,
};
case ACTION_NAME_FAIL:
return {
...state,
error: payload,
loading: false,
data: null,
};
default:
return state;
}
};
I'm trying to pass some value from a component to a action creators which is doing a get request with axios. I'm trying to follow this pattern from Dan Abramov :
export const SOME_ACTION = 'SOME_ACTION';
export function someAction() {
return (dispatch, getState) => {
const {items} = getState().otherReducer;
dispatch(anotherAction(items));
}
}
However I can't make it work. I think I have trouble on two level : my component and my action creator. Would be great to have some helps.
my component :
const timeR = ({
selectedTimeRange,
timeRange = [],
onTimeChange }) => {
return (
<div>
<div>
Filters:
<div>
Year:
<select
defaultValue={selectedTimeRange}
onChange={onTimeChange}>
<option value="all" >All</option>
{timeRange.map((y, i) =>
<option key={i} value={y}>{y}</option>
)}
</select>
</div>
</div>
</div>
);
}
function mapStateToProps(state) {
var range = ['30daysAgo', '15daysAgo', '7daysAgo'];
return {
selectedTimeRange: state.timeReducer.timerange[0],
timeRange: range
};
};
const mapDispachToProps = (dispatch) => {
return {
onTimeChange: (e) => {dispatch (onSetTimeRange(e.target.value));},
};
};
const TimeRange = connect(mapStateToProps, mapDispachToProps)(timeR);
export default TimeRange;
This component give me a dropdown menu. When selecting a timerange, for example '30daysAgo', it update my redux store state so I can access the value from my reducer.
Here is the action associated to my dropdown menu :
export function onSetTimeRange(timerange) {
return {
type: 'SET_TIME_RANGE',
timerange
}
}
and here is the action dealing with axios.get :
export const fetchgadata = () => (dispatch) => {
dispatch({
type: 'FETCH_DATA_REQUEST',
isFetching:true,
error:null
});
var VIEW_ID = "ga:80820965";
return axios.get("http://localhost:3000/gadata", {
params: {
id: VIEW_ID
}
}).then(response => {
dispatch({
type: 'FETCH_DATA_SUCCESS',
isFetching: false,
data: response.data.rows.map( ([x, y]) => ({ x, y }) )
});
})
.catch(err => {
dispatch({
type: 'FETCH_DATA_FAILURE',
isFetching:false,
error:err
});
console.error("Failure: ", err);
});
};
My question :
How do I bring these two actions together. At the end I would like to be able, when doing onChange on my drop-down menu, to call a action with the value selected from my menu as a param for my axios.get request.
I feel like I need to nest two actions creators. I've tried this but doesn't work ("fetchgadata" is read-only error in my terminal)
export const SET_TIME_RANGE = 'SET_TIME_RANGE';
export function onSetTimeRange() {
return (dispatch, getState) => {
const {VIEW_ID} = getState().timerange;
dispatch(fetchgadata = (VIEW_ID) => (dispatch) => {
dispatch({
type: 'FETCH_DATA_REQUEST',
isFetching:true,
error:null,
id:VIEW_ID,
});
});
return axios.get("http://localhost:3000/gadata", {
params: {
id: VIEW_ID
}
}).then(response => {
dispatch({
type: 'FETCH_DATA_SUCCESS',
isFetching: false,
data: response.data.rows.map( ([x, y]) => ({ x, y }) )
});
})
.catch(err => {
dispatch({
ype: 'FETCH_DATA_FAILURE',
isFetching:false,
error:err
});
console.error("Failure: ", err);
});
}
}
Edit:
reducers for API call :
const initialState = {data:null,isFetching: false,error:null};
export const gaData = (state = initialState, action)=>{
switch (action.type) {
case 'FETCH_DATA_REQUEST':
case 'FETCH_DATA_FAILURE':
return { ...state, isFetching: action.isFetching, error: action.error };
case 'FETCH_DATA_SUCCESS':
return Object.assign({}, state, {data: action.data, isFetching: action.isFetching,
error: null });
default:return state;
}
};
reducers for Drop-down :
const items = [{timerange: '30daysAgo'},{timerange: '15daysAgo'},{timerange: '7daysAgo'}]
const timeReducer = (state = {
timerange: items
}, action) => {
switch (action.type) {
case 'SET_TIME_RANGE':
console.log(state,action);
return {
...state,
timerange: action.timerange,
};
default:
return state;
}
}
I see a little typo in the catch of your axios.get request, it reads ype: FETCH_DATA_FAILURE. Otherwise, can you add in your reducer for me, I don't see it up there? If I understand correctly, you want one action to update two different pieces of state, in which case you would simply dispatch an action and add it to both reducers. Really it's best to just demonstrate:
//axios call
axios.get("some route", { some params } )
.then(response => {
dispatch({
type: UPDATE_TWO_THINGS,
payload: some_value
})
}) .... catch, etc
//reducer 1
import { UPDATE_TWO_THINGS } from 'types';
const INITIAL_STATE = { userInfo: '' };
export default function (state = INITIAL_STATE, action) {
switch(action.type) {
case UPDATE_TWO_THINGS:
return {...state, userInfo: payload };
}
return state;
}
//reducer 2
import { UPDATE_TWO_THINGS } from 'types';
const INITIAL_STATE = { businessInfo: '' };
export default function (state = INITIAL_STATE, action) {
switch(action.type) {
case UPDATE_TWO_THINGS:
return {...state, businessInfo: payload };
}
return state;
}
Hopefully this helps, but let me know if not, I'll do my best to get this working with you! Thanks for asking!