I am trying to store users fetched by random users api and trying to dispatch it to my store i have store users with an empty array, when i am trying to get users using useSelector i am getting an undefined object.
Here is my store.js:
import { configureStore } from "#reduxjs/toolkit";
import counterReducer from "../features/counter/counterSlice";
import userReducer from "../features/users/userSlice";
export const store = configureStore({
reducer: {
counter: counterReducer,
user: userReducer,
},
});
Here is userSlice.js
import { createSlice } from "#reduxjs/toolkit";
export const userSlice = createSlice({
name: "users",
initialState: {
userArray: [],
},
reducers: {
getUsers: (state, action) => {
state.userArray = action.payload;
}
}
})
export const { getUsers } = userSlice.actions;
export const selectUsers = (state) => state.users.userArray;
export default userSlice.reducer;
Here is App.js
import logo from './logo.svg';
import './App.css';
import {useSelector, useDispatch } from 'react-redux';
import { getUsers, selectUsers } from './features/users/userSlice';
function App() {
const dispatch = useDispatch();
const users = useSelector(selectUsers);
const fetchUsers = async () => {
fetch("https://gorest.co.in/public/v2/users")
.then((response) => response.json())
.then((data) => {
console.log("data=====", data);
dispatch(getUsers(data));
});
};
return (
<div className="App">
<header className="App-header">
<button onClick={fetchUsers}>Get Users</button>
{users.length > 0 &&
users.map((user) => {
<li>user.name</li>;
})}
</header>
</div>
);
}
export default App;
you are mixing up state.user and state.users
either rename user in configureStore to users or use state.user.userArray
Related
I'm trying to use React Redux on my application. I will be building something like instagram, so the scale of the application is going to be big. I have implement redux correctly (I believe) although I'm not getting the fetch result from firestore on the dispatch function, if I insert the same code before the return it works.
action/index.ts:
import { db, auth } from '../../services/firebase';
import { USER_STATE_CHANGE } from '../constants';
export function fetchUser() {
return (dispatch: any) => {
db.collection('users')
.doc(auth.currentUser!.uid)
.get()
.then((snapshot) => {
if (snapshot.exists) {
console.log(snapshot)
dispatch({
type: USER_STATE_CHANGE,
payload: snapshot.data(),
});
}
});
};
}
constants/index.ts:
export const USER_STATE_CHANGE = 'USER_STATE_CHANGE';
reducers/index.ts:
import { combineReducers } from 'redux';
import { user } from './user';
const Reducers = combineReducers({
userState: user,
});
export default Reducers;
reducers/user.ts:
const initialState = {
currentUser: null,
};
export const user = (state = initialState, action: any) => {
return {
...state,
currentUser: action.currentUser,
};
};
App.tsx:
// Redux
import { Provider } from 'react-redux';
import { createStore, applyMiddleware } from 'redux';
import rootReducer from './src/redux/reducers';
import thunk from 'redux-thunk';
const store = createStore(rootReducer, applyMiddleware(thunk));
export default function App() {
if (!fontsLoaded) return <></>;
return (
<ThemeProvider theme={theme}>
<Provider store={store}>
<Main />
</Provider>
<ToastMessage />
</ThemeProvider>
);
}
Main.tsx:
import React, { useEffect, useState } from 'react';
import { NavigationContainer } from '#react-navigation/native';
import { StatusBar } from 'expo-status-bar';
import { AuthRoutes } from './routes/auth.routes';
import { connect } from 'react-redux';
import { bindActionCreators } from 'redux';
import { fetchUser } from './redux/actions';
import { auth } from './services/firebase';
function Main() {
const [isAuthenticated, setIsAuthenticated] = useState(false);
useEffect(() => {
fetchUser();
auth.onAuthStateChanged((user) => {
if (user) setIsAuthenticated(true);
});
}, []);
return (
<NavigationContainer>
<AuthRoutes isAuthenticated={isAuthenticated} setIsAuthenticated={setIsAuthenticated} />
<StatusBar style="auto" />
</NavigationContainer>
);
}
const mapDispatchProps = (dispatch: any) => bindActionCreators({ fetchUser }, dispatch);
export default connect(null, mapDispatchProps)(Main);
The fetchUser() is called here, and should log the data from firestore, although I don't get any data logged.
The function is beeing called:
on reducer/user.ts
Have you try to do this:
const initialState = {
currentUser: null,
};
export const user = (state = initialState, action: any) => {
return {
...state,
currentUser: action.payload,
};
};
Replace this
export const user = (state = initialState, action: any) => {
return {
...state,
currentUser: action.currentUser,
};
};
With this
export const user = (state = initialState, action: any) => {
return {
...state,
currentUser: action.payload,
};
};
Because you are setting data in payload but you are accessing from currentUser which empty. Either replace payload with currentUser in useDispatch or replace currentUser with payload in reducer.
I'm trying to use redux on my current project. However, I can't use the dispatch data to another component.
Here's my code:
Authenticate.js
import { useDispatch, useSelector } from 'react-redux';
import { setLoginDetails } from 'redux/actions/loginActions';
function Authenticate() {
const [data, setData] = useState([]);
const dispatch = useDispatch();
const loginDetails = useSelector((state) => state);
const validateLogin = async() => {
const response = await.get('/api')
let responseValue = response.data.success
if(responseValue === true) {
let responseResp = JSON.parse(response.data.resp)
dispatch(setLoginDetails(responseResp.data.user))
/** here's the console logs
console.log('responseResp',responseResp)
console.log('AuthenticationOAK/responseResp.data.',responseResp.data)
console.log('AuthenticationOAK/responseResp.data.user',responseResp.data.user)
*/
window.location = '/home'
}
else{
//error
}
}
useEffect(()=>{
validateLogin();
},[])
return(
<div>Authenticating....</div>
)
}
export default Authenticate;
loginAction.js
import { ActionTypes } from '../constants/action-types';
export const setLoginDetails = (loginDetails) => {
return {
type: ActionTypes.SET_LOGIN,
payload: loginDetails,
}
}
action-types.js
export const ActionTypes = {
SET_LOGIN: 'SET_LOGIN',
}
loginReducer.js
import { ActionTypes } from '../constants/action-types';
const initialState = {
loginDetails: [],
}
export const loginReducer = (state = initialState, {type, payload}) => {
console.log('loginReducer/state', state)
console.log('loginReducer/payload',payload)
console.log('loginReducer/type', type)
console.log('loginReducer/initialState',initialState)
switch(type){
case ActionTypes.SET_LOGIN:
return {...state, loginDetails: payload}
default:
return state;
}
}
Home.js
import { useSelector } from 'react-redux';
function Home(){
const loginDetails = useSelector((state) => state.allLoginDetails.loginDetails)
const { email, userName, firstName } = loginDetails;
return(
<h1>username {userName}</h1>
)
}
export default Home;
index.js /redux/reducers/index.js
import { combineReducers } from 'redux'
import { loginReducer } from './loginReducer'
const reducers = combineReducers({
allLoginDetails: loginReducer,
});
export default reducers;
store.js
import { createStore } from 'redux'
import reducers from './index'
const store = createStore(
reducers,
{},
);
export dafault store;
Index.js
import React from 'react'
import { render } from 'react-dom'
import App from './App'
import {createStore} from 'redux'
import { Provider } from 'react-redux'
import store from '../src/redux/reducers/store'
render(
<Provider store={store}>
<App />
</Provider>,
document.getElementById('root'));
Below are the result of console logs from Authenticate.js
screenshots of console log from loginReducer.js
Hoping that you can help me with this, I'm having a hard time on this. Tried to use hard coded value on initialState and it's rendering properly. But when I use dynamic data it's not rendering. Thank you in advance. Stay safe!
in this file: Authenticate.js
useEffect(()=>{
Authenticate(); // it must be validateLogin()?
},[])
i've been working on a project trying to learn redux with react. But there is an error and i don't know exactly how to fix it. Files/codes in down if you need more information about how store works.
store/index.js
import { createStore, applyMiddleware, compose } from "redux";
import rootReducer from "./reducers";
import thunk from 'redux-thunk'
const middlewares = [thunk]
const store = createStore(rootReducer, compose(applyMiddleware(...middlewares), window.__REDUX_DEVTOOLS_EXTENSION__ && window.__REDUX_DEVTOOLS_EXTENSION__()))
export default store;
actions/index.js
import axios from "axios"
export const increment = (payload) => {
return {
type: 'INCREMENT',
payload: payload
}
}
export const decrement = () => {
return {
type: 'DECREMENT'
}
}
export const fetch = () => {
return async (dispatch) => {
axios.get('https://jsonplaceholder.typicode.com/posts/')
.then(data => dispatch({type: 'FETCH', payload: data.data}))
}
}
store/todos.js
const todos = (state = [], action) => {
switch(action.type){
case 'FETCH':
return Object.assign(state, action.payload);
default:
return state;
}
}
export default todos;
App.js
import logo from './logo.svg';
import './App.css';
import {useSelector, useDispatch, connect} from 'react-redux'
import {increment, decrement, fetch} from './store/actions/'
import { GeistProvider, CssBaseline } from '#geist-ui/react';
function App(props) {
const count = useSelector((state) => state.counter)
const todos = useSelector((state) => state.todos)
const dispatch = useDispatch()
return (
<div className="App">
<header className="App-header">
<h1>Count is {count}</h1>
<button onClick={() => dispatch(increment(3))}>+</button>
<button onClick={() => dispatch(decrement())}>-</button>
<button onClick={() => dispatch(fetch())}>FETCH</button>
{todos.length ? todos[0].title : <h1>Not fetched.</h1>}
</header>
</div>
);
}
export default App;
This is the codes in project. Let me know if you guys need more information about anything. Thanks for help!
You are wrong at return Object.assign(state, action.payload);. It's mutated state so redux can't detect state change. You should read this https://redux.js.org/understanding/thinking-in-redux/three-principles#changes-are-made-with-pure-functions
You can change to this
return Object.assign({}, state, action.payload);
or this
return { ...state, ...action.payload }
Getting a weird error where 'map' is undefined. I'm not sure if my functions are firing at the wrong time and that's resulting in no data being received.
I'm adding Redux into my simple little application that just pulls data from an API and displays it. It's a list of a bunch of Heroes. Like I said before, I think that the error is coming from different times in the ansyc API call and when Redux is firing. But then again I'm a novice so any help is much appreciated.
import React, {useEffect} from 'react'
import { connect } from 'react-redux'
import { fetchHeroes } from '../actions/heroesActions'
import { Hero } from '../components/Hero'
const HeroesPage = ({ dispatch, loading, heroes, hasErrors }) => {
useEffect(() => {
dispatch(fetchHeroes())
}, [dispatch])
const renderHeroes = () => {
if (loading) return <p>Loading posts...</p>
if (hasErrors) return <p>Unable to display posts.</p>
return heroes.map(hero => <Hero key={hero.id} hero={hero} />)
}
return (
<section>
<h1>Heroes</h1>
{renderHeroes()}
</section>
)
}
// Map Redux state to React component props
const mapStateToProps = state => ({
loading: state.heroes.loading,
heroes: state.heroes.heroes,
hasErrors: state.heroes.hasErrors,
})
export default connect(mapStateToProps)(HeroesPage)
export const GET_HEROES = 'GET HEROES'
export const GET_HEROES_SUCCESS = 'GET_HEROES_SUCCESS'
export const GET_HEROES_FAILURE = 'GET_HEROES_FAILURE'
export const getHeroes = () => ({
type: GET_HEROES,
})
export const getHeroesSuccess = heroes => ({
type: GET_HEROES_SUCCESS,
payload: heroes,
})
export const getHeroesFailure = () => ({
type: GET_HEROES_FAILURE,
})
export function fetchHeroes() {
return async dispatch => {
dispatch(getHeroes())
try {
const response = await fetch('https://api.opendota.com/api/heroStats')
console.log(response)
const data = await response.json()
dispatch(getHeroesSuccess(data))
} catch (error) {
dispatch(getHeroesFailure())
}
}
}
index.js where I created the store
// External imports
import React from 'react'
import { render } from 'react-dom'
import { createStore, applyMiddleware } from 'redux'
import { Provider } from 'react-redux'
import thunk from 'redux-thunk'
import { composeWithDevTools } from 'redux-devtools-extension'
// Local imports
import App from './App'
import rootReducer from './reducers'
const store = createStore(rootReducer, composeWithDevTools(applyMiddleware(thunk)))
render(
<Provider store={store}>
<App />
</Provider>,
document.getElementById('root')
)
import React, {useEffect} from 'react'
import { useSelector } from 'react-redux'
import { fetchHeroes } from '../actions/heroesActions'
import { Hero } from '../components/Hero'
const HeroesPage = () => {
const data = useSelector(state => state.heroes);
useEffect(() => {
fetchHeroes();
}, [])
const renderHeroes = () => {
if (data.loading) return <p>Loading posts...</p>
if (data.hasErrors) return <p>Unable to display posts.</p>
return data.heroes.map(hero => <Hero key={hero.id} hero={hero} />)
}
return (
<section>
<h1>Heroes</h1>
{renderHeroes()}
</section>
)
}
export default HeroesPage
action file
// import store from your createStore file and access dispatch from it
dispatch = store.dispatch
export const GET_HEROES = 'GET HEROES'
export const GET_HEROES_SUCCESS = 'GET_HEROES_SUCCESS'
export const GET_HEROES_FAILURE = 'GET_HEROES_FAILURE'
export const getHeroes = () => ({
type: GET_HEROES,
})
export const getHeroesSuccess = heroes => ({
type: GET_HEROES_SUCCESS,
payload: heroes,
})
export const getHeroesFailure = () => ({
type: GET_HEROES_FAILURE,
})
export const fetchHeroes = () => {
dispatch(getHeroes())
try {
const response = await fetch('https://api.opendota.com/api/heroStats')
console.log(response)
const data = await response.json()
dispatch(getHeroesSuccess(data))
} catch (error) {
dispatch(getHeroesFailure())
}
}
reducer file
import * as actions from '../actions/heroesActions'
export const initialState = {
heroes: [],
loading: false,
hasErrors: false,
}
export default function heroesReducer(state = initialState, action) {
switch (action.type) {
case actions.GET_HEROES:
return { ...state, loading: true }
case actions.GET_HEROES_SUCCESS:
return { heroes: action.payload, loading: false, hasErrors: false }
case actions.GET_HEROES_FAILURE:
return { ...state, loading: false, hasErrors: true }
default:
return state
}
}
I am developing a lottery statistics app that gets data from a csv loaded from an input then I was wanting to read this data to the redux store so I can use it across multiple components.
I have successfully saved the data to the redux store once I import the file and read it through Header.js and using an action, but I am not sure how to access this in other components like e.g. Main.js.
I feel like I am still confused on how react/redux all fits together. I'm sorry if this has been asked before but everything I looked up online I couldn't get to work.
// index.js
import React from "react";
import ReactDOM from "react-dom";
import { createStore, applyMiddleware } from "redux";
import { Provider } from "react-redux";
import thunk from "redux-thunk";
import reducers from "./reducers";
import App from "./components/App";
const store = createStore(reducers, applyMiddleware(thunk));
ReactDOM.render(
<Provider store={store}>
<App />
</Provider>,
document.querySelector("#root")
);
// App.js
import React from "react";
import Header from "./Header";
import Main from "./Main";
const App = () => {
return (
<div>
<Header />
<Main />
<div className="numbers-for-draw"></div>
</div>
);
};
export default App;
// Header.js
import React from "react";
import { CSVReader } from "react-papaparse";
import { fetchData } from "../actions";
import { connect } from "react-redux";
class Header extends React.Component {
constructor(props) {
super(props);
this.fileInput = React.createRef();
}
handleReadCSV = data => {
this.props.fetchData(data);
console.log(this.props.data);
};
handleOnError = (err, file, inputElem, reason) => {
console.log(err);
};
handleImportOffer = () => {
this.fileInput.current.click();
console.log("Got to handleImportOffer");
};
render() {
return (
<header>
<CSVReader
onFileLoaded={this.handleReadCSV}
inputRef={this.fileInput}
style={{ display: "none" }}
onError={this.handleOnError}
/>
<button onClick={this.handleImportOffer}>Import</button>
</header>
);
}
}
//Map what is in the redux store (e.g. state) to props
const mapStateToProps = state => ({
data: state.data
});
export default connect(mapStateToProps, {
fetchData: fetchData
})(Header);
// Main.js
import React from "react";
import { fetchData } from "../actions";
import { connect } from "react-redux";
const Main = () => {
console.log("In main");
console.log(this.props.data); //Blows up here.
return <div>Main</div>;
};
//Map what is in the redux store (e.g. state) to props
const mapStateToProps = state => ({
data: state.data
});
export default connect(mapStateToProps, {
fetchData: fetchData
})(Main);
// actions/index.js
export const fetchData = data => dispatch => {
console.log("Action");
const lottoData = {
stringNumbers: [
"one",
"two",
"three",
...
],
allResults: [],
winningNumbers: [],
winningNumbersAsStrings: []
};
const localData = data.data;
localData.shift();
localData.forEach(line => {
const lineObject = {
draw: line[0],
drawDate: line[1],
ballOne: line[2],
ballTwo: line[3],
ballThree: line[4],
ballFour: line[5],
ballFive: line[6],
ballSix: line[7],
bonusBall: line[8],
bonusBall2: line[9],
powerBall: line[10]
};
lottoData.allResults.push(lineObject);
let nums = [];
nums.push(parseInt(line[2]));
nums.push(parseInt(line[3]));
nums.push(parseInt(line[4]));
nums.push(parseInt(line[5]));
nums.push(parseInt(line[6]));
nums.push(parseInt(line[7]));
nums.sort((a, b) => {
if (a < b) {
return -1;
} else if (a > b) {
return 1;
} else {
return 0;
}
});
lottoData.winningNumbers.push(nums);
lottoData.winningNumbersAsStrings.push(nums.toString());
});
dispatch({ type: "FETCH_DATA", payload: lottoData });
};
// lottoReducer.js
export default (state = {}, action) => {
switch (action.type) {
case "FETCH_DATA":
return action.payload;
default:
return state;
}
};
// reducers/index.js
import { combineReducers } from "redux";
import lottoReducer from "./lottoReducer";
export default combineReducers({
data: lottoReducer
});
I haven't tested your code, but it seems to me that the only problem is in your Main.js
While you use a function component and not a class, you shouldn't use this to access your props. The following should work as expected:
const Main = (props) => {
console.log("In main");
console.log(props.data);
return <div>Main</div>;
};
//Map what is in the redux store (e.g. state) to props
const mapStateToProps = state => ({
data: state.data
});
export default connect(mapStateToProps, {
fetchData: fetchData
})(Main);
In your main.js you used functional components so this.props doesn't work there. You must pass props to your component and console.log(props.data).