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React class Component not re render after props change from redux action

The component does not re render after successfully update state in redux
i have tried to do some condition in componentShouldUpdate end up with loading true without change
reducer.js
import * as types from "./actionsType";
const INITIAL_STATE = {
slide_data: [],
error: null,
loading: false,
};
const updateObject = (oldObject, updatedProperties) => {
return {
...oldObject,
...updatedProperties,
};
};
const slideReducer = (state = INITIAL_STATE, action) => {
switch (action.type) {
case types.SLIDES_FETCH_START:
return updateObject(state, {
error: null,
loading: true,
});
case types.SLIDES_FETCH_SUCSSES:
return updateObject(state, {
slide_data: action.payload,
error: null,
loading: false,
});
case types.SLIDES_FETCH_FAIL:
return updateObject(state, {
error: action.error,
loading: false,
});
default:
return state;
}
};
export default slideReducer;
actions.js
import * as types from "./actionsType";
import axios from "axios";
import { selectSlides } from "./slides.selectors";
export const slidesStart = () => {
return {
type: types.SLIDES_FETCH_START,
};
};
export const slidesSucces = (slides) => {
return {
type: types.SLIDES_FETCH_SUCSSES,
payload: slides,
};
};
export const slidesFail = (error) => {
return {
type: types.SLIDES_FETCH_FAIL,
error: error,
};
};
export const fetchSlides = () => {
return (dispatch) => {
console.log("fetch Start");
dispatch(slidesStart());
axios
.get("http://127.0.0.1:8000/slides/", {
headers: {
"Content-Type": "application/json",
},
})
.then((res) => {
dispatch(slidesSucces(res.data));
})
.catch((err) => dispatch(slidesFail(err)));
};
};
component
class IntroPage extends Component {
constructor(props) {
super(props);
this.tlitRef = React.createRef();
this.titlelRef = React.createRef();
this.subTitleRef = React.createRef();
this.showcase = React.createRef();
}
componentDidMount() {
this.props.fetchSlides();
}
render() {
const { slides, loading } = this.props;
if (loading) {
return <h1>Loading</h1>;
}
return (
<div className="intro">
<div className="wrapper">
{slides.map((data) => (
<SwiperSlides data={data} key={data.name} />
))}
</div>
</div>
);
}
}
const mapStateToProps = (state) => {
return {
loading: state.slides.loading,
error: state.slides.error,
slides: state.slides.slide_data,
};
};
const mapDispatchToProps = (dispatch) => {
return {
fetchSlides: () => dispatch(fetchSlides()),
};
};
export default connect(mapStateToProps, mapDispatchToProps)(IntroPage);
Register the redux-logger correctly. The data was returned but nothing changes when I do redux-persist and try to reload data come through
update ::
when I change the size of the browser data it correctly appears what is this !!

update : this problem related to swiperjs
and the solution will be like that:
1 - assign swiper instance to React.CreateRef(null) : this.swiper = React.CreateRef(null)
2 - in componentDidUpdate() make a swiper update : this.swiper.current.update()
4 - use a arrow function syntax in swiper on functions to refer to the outer scope

Async api fetch with redux thunk

I'm having trouble fetching a list of users from an api. I think issue might be in my mapDispatchToProps function but I'm not sure. Everything else seems fine to me. I'm new to redux and I'm kinda having a hard time wrapping my head around it so any help is appreciated
The list with the users would ideally be displayed as soon as the component mounts. I did the same thing without redux store and it was working just fine, I'm just not really sure how to integrate redux
Actions
export const startLoading = () => {
return {
type: START_LOADING
}
}
export const updateUserData = payload => {
return {
type: UPDATE_USER_DATA,
payload
}
}
export const updateUserError = payload => {
return {
type: UPDATE_USER_ERROR,
payload: payload
}
}
export function fetchUsers() {
return dispatch => {
dispatch(startLoading());
fetch('https://jsonplaceholder.typicode.com/users')
.then(res => res.json())
.then(data => {
data = data.filter(user => user.id < 4);
data.forEach(user => {
user.isGoldClient = false;
user.salary = '4000';
user.photo = userThumbnail;
})
.then(data => {
dispatch(updateUserData(data));
}).catch(error => {
dispatch(updateUserError(error));
})
});
};
};
Reducers
const initialState = {
loading: false,
users: [],
error: null
};
export function userReducer(state=initialState, action){
switch(action.type){
case START_LOADING:
return {
...state,
loading: true
}
case UPDATE_USER_DATA:
return {
...state,
loading: false,
users: action.payload,
error: null
}
case UPDATE_USER_ERROR:
return {
...state,
error: action.payload,
loading: false,
users: []
};
default:
return state;
};
};
Component
class Home extends React.Component {
constructor(props) {
super(props);
this.state = {
users: [],
usersAreDisplayed: true
};
}
componentDidMount() {
fetchUsers();
}
render(){
return (
<UserList users={this.state.users} />
)
}
}
function mapStateToProps(state){
return { users: state.users }
}
function mapDispatchToProps(dispatch){
return {
fetchUsers: payload => dispatch(updateUserData(payload)),
}
}
export default connect(mapStateToProps, mapDispatchToProps)(Home);

Looks like you are not calling the actual fetchUsers at all.
Change the component code like this
function mapStateToProps(state){
return { users: state.users }
}
// remove this function
// function mapDispatchToProps(dispatch){
// return {
// fetchUsers: payload => dispatch(updateUserData(payload)),
// }
// }
export default connect(mapStateToProps, {fetchUsers})(Home); //<---- destructure it here. Also import the function (action)
1a. fetchUsers function needs to be accessed using this.props
componentDidMount() {
this.props.fetchUsers();
}
There is an extra then block after forEach.
Remove it.
export function fetchUsers() {
return (dispatch) => {
dispatch(startLoading());
fetch("https://jsonplaceholder.typicode.com/users")
.then((res) => res.json())
.then((data) => {
data = data.filter((user) => user.id < 4);
data.forEach((user) => {
user.isGoldClient = false;
user.salary = "4000";
user.photo = userThumbnail;
});
dispatch(updateUserData(data)); // <------ no extra .then is required
})
.catch((error) => {
dispatch(updateUserError(error));
});
};
}
Also <UserList users={this.state.users} /> needs to be <UserList users={this.props.users} /> As already mentioned by #Nsevens

You are mapping redux state into your component's props.
So you should load the users from the component's props and not it's state:
render(){
return (
<UserList users={this.props.users} />
)
}

Unable to handle state 'loading' properly in react with redux

Hey guys just moved to redux so in react what i was doing was in componentDidMount(), i was calling api and soon as i received the data i was setting loading to false (initially loading was true) to get rid of the 'react spinner',
but after using redux now in componentDidMount() i am calling my action creater which is in another and there i am receving my data so how do i manage 'loading' here ? can i somehow pass something from action creater to my component that triggers state and set loading to false ? or is there any other to do it ? How do you all manage it ?
here is my code
Home.js
class home extends Component {
UNSAFE_componentWillMount() {
this.props.verifyToken();
}
componentDidMount() {
this.props.categoryAction();
}
constructor(props) {
super(props);
this.state = {
categoriesWithTheirImages: [],
displayToggle: false,
loading: false,
};
}
renderCategory = () => {
return this.props.allCategories.map((item) => {
return (
<div
className="category_div"
key={item._id}
onClick={() => this.setState({ displayToggle: true })}
>
<img
src={item.image}
alt="miss-mistake"
className="category_image_home"
/>
<span className="category_heading_home">{item.categoryName}</span>
</div>
);
});
};
render() {
if (this.state.loading) {
return (
<div className="sweet-loading-main">
<FadeLoader
css={override}
sizeUnit={"px"}
size={50}
color={"#ff9d72"}
loading={this.state.loading}
/>
</div>
);
} else {
console.log(this.props.allCategories);
return (
<React.Fragment>
{/* <Fade left> */}
<Header />
<div className="main_content_homepage">
<p className="category_select">Please select a category</p>
<div className="category_list">{this.renderCategory()}</div>
</div>
{this.renderStoryActionDialog()}
{/* </Fade> */}
</React.Fragment>
);
}
}
}
const mapStateToProps = (state) => {
console.log(state);
const images = [family, ring, beer, feedback, academic];
let categoriesWithImages = state.getCategoryReducer.map((item, index) => {
item.image = images[index];
return item;
});
console.log(categoriesWithImages);
return { allCategories: categoriesWithImages };
};
export default connect(mapStateToProps, { verifyToken, categoryAction })(home);
and my action.js file
import { CATEGORY } from "../actionTypes";
export const categoryAction = ()=> {
return dispatch => {
fetch("http://localhost:3000/api/get_categories", {
method: "GET",
}).then(res=>res.json())
.then(response => {
console.log(response)
dispatch({ type: CATEGORY, payload: response });
})
.catch(err => console.log("Eror in adding", err));
};
};
reducer file
import { USER, CATEGORY} from "../actionTypes";
const getCategoryReducer = (state = [], action) => {
switch (action.type) {
case CATEGORY:
return action.payload;
default:
return state;
}
};
export default getCategoryReducer;

You should handle the loading state in your reducer file. At the moment, it's defined in your Component file. For e.g when you dispatch the action, it should update your loading state too. I would do something like this in reducer.
import { USER, FETCH_CATEGORY, FETCH_CATEGORY_SUCCESS, FETCH_CATEGORY_FAIL} from "../actionTypes";
const INITIAL_STATE = {
loading: false,
err: false,
data: []
}
const getCategoryReducer = (state = INITIAL_STATE, action) => {
switch (action.type) {
case FETCH_CATEGORY:
return Object.assign({}, state, {
loading: true,
data: [],
})
case FETCH_CATEGORY_SUCCESS
return Object.assign({}, state, {
loading: false,
data: action.payload,
})
case FETCH_CATEGORY_FAIL
return Object.assign({}, state, {
loading: false,
data: action.payload,
err: true
})
default:
return state;
}
};
export default getCategoryReducer;
and your action file would look something like this
import { FETCH_CATEGORY, FETCH_CATEGORY_SUCCESS, FETCH_CATEGORY_FAIL } from "../actionTypes";
export const categoryAction = ()=> {
//setting loading to true
return dispatch => {
dispatch({ type: FETCH_CATEGORY });
fetch("http://localhost:3000/api/get_categories", {
method: "GET",
}).then(res=>res.json())
.then(response => {
//setting loading to false
dispatch({ type: FETCH_CATEGORY_SUCCESS, payload: response });
})
.catch(err => console.log("Eror in adding", err); dispatch({ type: FETCH_CATEGORY_FAIL, payload: err }););
};
};
You can then read the loading props in your Home.js

React Redux Data not being passed to props

I am new to React/Redux and I am stuck in a problem. My fetched data from API is not being passed to props. It's always an empty object.
I see that there might be some issues that I am not even aware of but I don't have a clue where to look for.
Please check my codes below:
RegisterPage.jsx
import { connect } from 'react-redux';
import { userActions } from '../_actions';
class RegisterPage extends React.Component {
constructor(props) {
super(props);
this.state = {
user: {
first_name: '',
last_name: '',
properties_id: '',
email: '',
phone_number: '',
password: ''
},
submitted: false,
checked: false,
};
this.handleChange = this.handleChange.bind(this);
this.handleSubmit = this.handleSubmit.bind(this);
}
componentDidMount() {
this.props.dispatch(userActions.getAll());
}
handleChange(event) {
const { name, value } = event.target;
const { user } = this.state;
this.setState({
user: {
...user,
[name]: value
},
checked: !this.state.checked
});
}
handleSubmit(event) {
event.preventDefault();
this.setState({ submitted: true });
const { user } = this.state;
const { dispatch } = this.props;
if(this.state.checked) {
if (user.first_name && user.last_name && user.properties_id &&
user.email && user.phone_number && user.password) {
dispatch(userActions.register(user));
}
} else {
alert("Please tick the checkbox to agree to Terms and Conditions");
}
}
render() {
const { registering, properties } = this.props;
const { user, submitted } = this.state;
return (......)
}
function mapStateToProps(state) {
const { registering } = state.registration;
const { properties } = state;
return {
properties,
registering
};
}
const connectedRegisterPage = connect(mapStateToProps)(RegisterPage);
export { connectedRegisterPage as RegisterPage };
users.reducers.js
export function users(state = {}, action) {
switch (action.type) {
case userConstants.GETALL_REQUEST:
return {
loading: true
};
case userConstants.GETALL_SUCCESS:
return {
items: action.properties
//action.users
};
case userConstants.GETALL_FAILURE:
return {
error: action.error
};
default:
return state
}
}
user.actions.js
export const userActions = {
login,
logout,
register,
getAll,
delete: _delete
};
function getAll() {
return dispatch => {
dispatch(request());
userService.getAll()
.then(
properties => dispatch(success(properties)),
error => dispatch(failure(error.toString()))
);
};
function request() { return { type: userConstants.GETALL_REQUEST } }
function success(properties) { return { type: userConstants.GETALL_SUCCESS, properties } }
function failure(error) { return { type: userConstants.GETALL_FAILURE, error } }
}
user.service.js
// Get All Properties
function getAll() {
const requestOptions = {
method: 'GET'
};
return fetch(`${config.apiUrl}/api/properties`, requestOptions).then(handleResponse).then(
properties => {
return properties;
}
);
}
Here's the screenshot of the console:
It is clear that properties array is not empty. But when I am going to use properties, it is empty. I don't know what's wrong. If anyone could help figure out what's wrong with my code or something that I missed, your help will be greatly appreciated. I just need to fix this so I could move forward. Thanks in advance!

I thinking that your state tree might not contain state.properties but instead state.items. Unless if you did something in combineReducers() that changes the shape of it again.
case userConstants.GETALL_SUCCESS:
return {
items: action.properties
//action.users
};
This part would probably cause action.properties to be stored in state.items instead of state.properties
I'd recommend using ReduxDevTools to make your life with state easier

React JS & Redux : this.props. is undefined

I have read a lot of threads about my issue but none of them helped me.
I developed a JWT authentication app using React.JS and Redux with a django rest framework API as backend.
User information is sent to authenticated user through a GET request :
{
"id": 1,
"email": "",
"first_name": "",
"last_name": ""
}
user.actions.js (redux action)
export const loadUser = () => {
return (dispatch) => {
const token = localStorage.getItem('token');
if (token) {
axios.get('http://localhost:8000/auth/user/', {
headers: { 'Authorization': 'token ' + token }
})
.then(res => {
dispatch({ type: USER_LOADED, data: JSON.stringify(res.data) })
}).catch((error) => {
// catch later
})
}
};
};
auth.reducers.js
import {
SIGNIN_REQUEST,
SIGNIN_SUCCESS,
SIGNIN_FAILURE,
SIGNOUT,
USER_LOADED
} from '../_constants/user.constants';
const initialState = { }
export function auth(state = {}, action) {
switch (action.type) {
case SIGNIN_REQUEST:
return { ...state, isLogging: true }
case SIGNIN_SUCCESS:
return { ...state, isLogged: true }
case SIGNIN_FAILURE:
return { ...state, error: action.data, isLogged: false, isLogging: false }
case USER_LOADED:
return { ...state, isLogged: true, user: action.data }
case SIGNOUT:
return { }
default:
return state;
}
};
App.js
class App extends Component {
componentDidMount() {
let token = localStorage.getItem('token');
if (token) {
this.props.loadUser();
}
}
render() {
return (
<div className="container-scroller">
<BrowserRouter>
<Router history={History}>
<Switch>
...
</Switch>
</Router>
</BrowserRouter>
</div>
);
}
}
const mapStateToProps = state => {
return {
auth: state.auth
}
}
const mapDispatchToProps = dispatch => {
return {
loadUser: () => {
return dispatch(userActions.loadUser());
}
}
};
export default connect(mapStateToProps, mapDispatchToProps)(App);
Everything works fine. The data is correctly fetch. When I write {this.props.auth.user} in my render method, it displays the data correctly (as sent by the API) :
{"id":1,"email":"","first_name":null,"last_name":null}
But when I try to display a value of the data (id, email, ...) it shows an error : (with map or this.props.auth.user['id']
TypeError: this.props.auth.user is undefined
How can I display the data properly ?
Thanks in advance :)