I can't understand why my Redux props are showing empty on the React component. This is the screenshot of the Redux state:
This is the component that visualizes. It is a child of a parent component that fetches the data and runs a for loop through the array of elements.
import React, { Component } from 'react'
import { connect } from "react-redux";
import PropTypes from "prop-types";
class ResourceCard extends Component {
render() {
const { resource } = this.props;
return (
<div className="resource-card">
<div className="resource-card-header">
<span className="res-span-header">{resource.header}</span>
</div>
<div className="resource-card-image">
<img src={resource.image} alt={resource.header} width='300px' />
</div>
<div className="resource-card-desc">
<span className="res-span-desc">{resource.description}</span>
</div>
<div className="resource-card-link">
<span className="res-span">{resource.website}</span>
</div>
</div>
)
}
}
ResourceCard.propTypes = {
resource: PropTypes.object.isRequired,
auth: PropTypes.object.isRequired
};
const mapStateToProps = state => ({
auth: state.auth,
resource: state.resource
});
export default connect(
mapStateToProps,
{}
)(ResourceCard);
While the css is being rendered properly, and there are no errors in the console, the content itself is not there:
What could possibly be wrong here?
EDITED: Adding actions code:
// Get Resources
export const getResources = () => dispatch => {
axios
.get("/api/resources")
.then(res =>
dispatch({
type: GET_RESOURCES,
payload: res.data
})
)
.catch(err =>
dispatch({
type: GET_RESOURCES,
payload: null
})
);
};
And the reducer:
import {
ADD_RESOURCE,
GET_RESOURCES,
DELETE_RESOURCE,
GET_RESOURCE
} from "../actions/types";
const initialState = {
resources: [],
resource: {}
};
export default function(state = initialState, action) {
switch (action.type) {
case GET_RESOURCES:
return {
...state,
resources: action.payload
};
case GET_RESOURCE:
return {
...state,
resource: action.payload
};
case DELETE_RESOURCE:
return {
...state,
resources: state.resources.filter(resource => resource._id !== action.payload)
};
case ADD_RESOURCE:
return {
...state,
resources: [action.payload, ...state.resources]
};
default:
return state;
}
}
Parent component that runs a for-loop:
import React, { Component } from 'react'
import PropTypes from 'prop-types'
import ResourceCard from './ResourceCard';
class ResourceFeed extends Component {
render() {
const { resources } = this.props;
return resources.map(resource => <ResourceCard key={resource._id} resource={resource} />)
}
}
ResourceFeed.propTypes = {
resources: PropTypes.array.isRequired
}
export default ResourceFeed;
And the component above contains this parent:
<ResourceFeed resources={resources}/>
Issue is here:
const mapStateToProps = state => ({
auth: state.auth,
resource: state.resource // <========== in this line
});
In ResourceCard component you are passing the resource props from two places, one from parent component and one from redux store, that's why.
Your component is expecting the resource value from parent, so remove this line:
resource: state.resource
Related
currently working on adding the items to cart using react and redux but the add item does not work
I'm taking the items from my collections page and then passing the key to the product preview page
I'm using react-redux cartReducer the three files are
just can't figure out how to pass the fish products
product page
cart actions
cart reducer
import React, { Component } from 'react';
import { Link } from 'react-router-dom';
import firebase from '../../firebase/firebase';
import { connect } from 'react-redux';
import { addItem } from '../../redux/cart/cart-actions'
class FishPage extends Component {
constructor(props) {
super(props);
this.ref = firebase.firestore().collection('fishproducts');
this.unsubscribe = null;
this.state = {
fishproducts: []
};
}
componentDidMount() {
const ref = firebase.firestore().collection('fishproducts').doc(this.props.match.params.id);
ref.get().then((doc) => {
if (doc.exists) {
this.setState({
fishproducts: doc.data(),
key: doc.id,
isLoading: false
});
} else {
console.log("No such document!");
}
});
}
render() {
return (
<div >
<div>
<div>
<h4><Link to="/">back</Link></h4>
<h3>
{this.state.fishproducts.name}
</h3>
</div>
<div >
<dl>
<dt>Description:</dt>
<dd>{this.state.fishproducts.description}</dd>
<dt>Discount:</dt>
<dd>{this.state.fishproducts.discount}</dd>
<dt>Size:</dt>
<dd>{this.state.fishproducts.size}</dd>
<dt>Weight:</dt>
<dd>{this.state.fishproducts.weight}</dd>
<dt>Price:</dt>
<dd>{this.state.fishproducts.price}</dd>
<dt>Stock:</dt>
<dd>{this.state.fishproducts.stock}</dd>
</dl>
<button onClick={() => addItem(this.state.fishproducts)} >ADD TO CART</button>
</div>
</div>
</div>
);
}
}
const mapDispatchToProps = dispatch => ({
addItem: item => dispatch(addItem(item))
})
export default connect(null, mapDispatchToProps)(FishPage);```
this is cart action page
```import CartActionTypes from './cart-types';
export const toggleCartHidden = () => ({
type:CartActionTypes.TOGGLE_CART_HIDDEN
});
export const addItem = item => ({
type: CartActionTypes.ADD_ITEM,
payload: item
})```
this is cart reducer
```import CartActionTypes from './cart-types';
const INITIAL_STATE = {
hidden: true,
cartItems: []
};
export const cartReducer = (state = INITIAL_STATE, action) => {
switch (action.type) {
case CartActionTypes.TOGGLE_CART_HIDDEN:
return {
...state,
hidden: !state.hidden
};
case CartActionTypes.ADD_ITEM:
return {
...state,
//cartItems: addItem(state.cartItems, action.payload)
cartItems: [...state.cartItems,action.payload]
};
default:
return state;
}
}
export default cartReducer;```
cant figure out how to pass fishproducts
So concept of React is that you need to access Firebase with a function. For that you should use a functional component.
React allows Hooks to get access to your state without a constructor so that's all
and then you'll need to use dispatch.
import React, { useState, useEffect } from 'react';
import firebase from '../../firebase/firebase';
import { Link } from 'react-router-dom';
import { connect , useDispatch} from "react-redux";
import { addItem} from '../../redux/cart/cart-actions';
const FishPage = (props) => {
const [state, setState] = useState({
name: '',
… rest of the values
isLoading: true,
})
const { name, … rest of the values } = state;
useEffect(() => {
setState({ isLoading: true });
const ref = firebase.firestore().collection('fishproducts').doc(props.match.params.id);
ref.get().then((doc) => {
setState({
name: doc.data().name,
… rest of the values
isLoading: false,
});
})
}, [props.match.params.id])
const item = [];
const dispatch = useDispatch();
return (
<div >
<div>
//your body here
<button onClick={() => dispatch(addItem(item))} >ADD TO CART</button>
</div>
</div>
</div>
);
}
const mapDispatchToProps = dispatch => {
return{
addItem: (item) => dispatch(addItem(item))
}
}
export default connect(null, mapDispatchToProps)(FishPage)
I am creating a web app where a user chooses a restaurant on one screen and the name of the restaurant is stored and then the menu screen checks the state for the restaurant name and gets the menu items from the server for that restaurant. When I press the button in userscreen.js the first time, the state doesn't change but it does change the next time. However, when I check the state from menu.js it is still the initialized state, which is empty. How do I get the state to not change back to its original value?
Here are the files im working on:
userscreen.js
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { setRestaurant } from '../actions/restaurant';
class Userscreen extends Component {
constructor(props){
super(props);
this.state={
r2:'',
};
this.handleClick1 = this.handleClick1.bind(this);
}
componentDidMount(){
fetch('api/rest-ratings', {
method: 'GET'
})
.then(res => res.json())
.then(body =>{
this.setState({r2: body.C})
})
}
handleClick1(event){
event.preventDefault()
this.props.setRestaurant("ChopChop");
console.log(this.props.rest)
}
render() {
return (
<div>
<img src={user_background} alt="" style= {{width: "100%", height: "auto", margin:"0auto"}}/>
<div id="btn2" onClick={this.handleClick1}>
Chop Chop
<div>
<StarRatingComponent name="ChopChop" editing={false} starCount={5} value={parseInt(this.state.r2)}/>
</div>
</div>
</div>
);
}
}
const mapStateToProps = (state) => ({
rest: state.rest,
})
export default connect(mapStateToProps, { setRestaurant })(Userscreen)
menu.js
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { setRestaurant } from '../actions/restaurant';
class Menu extends Component {
constructor(props){
super(props);
this.state={
rest1: 'abc',
};
}
componentDidMount(){
console.log("mine",this.state.rest1)
console.log("store",this.props.rest)
}
render() {
return (
<div>
{this.state.rest}
</div>
);
}
}
const mapStateToProps = (state) => ({
rest: state.rest
})
export default connect(mapStateToProps, {setRestaurant})(Menu);
restaurant.js
export const setRestaurant = (restaurant) => dispatch => {
dispatch({
type: 'SET_RESTAURANT',
payload: restaurant
})
}
restReducer.js
const initialState = {
restaurant : ''
}
export default function(state = initialState, action ) {
switch(action.type) {
case 'SET_RESTAURANT':
return {
...state,
restaurant: action.payload,
}
default:
return state;
}
}
index.js
import { combineReducers } from 'redux';
import errorReducer from './errorReducer';
import authReducer from './authReducer';
import restReducer from './restReducer';
export default combineReducers({
errors: errorReducer,
auth: authReducer,
rest: restReducer
});
Your dispatch binder function should be defined as a simple action creator if it is going to be used like it is in export default connect(mapStateToProps, {setRestaurant})(Menu);:
export const setRestaurant = restaurant => ({
type: 'SET_RESTAURANT',
payload: restaurant
})
See defining mapDispatchToProps as an object
Also note that the mapStateToProps function passes the returned object via the props (as the name suggests) so using those passed in props should be done through this.props (instead of this.state).
return (
<div>{this.props.rest.restaurant}</div>
)
I am fairly new to React and Redux and I have an issue with my component not updating on the final dispatch that updates a redux store. I am using a thunk to preload some data to drive various pieces of my site. I can see the thunk working and the state updating seemingly correctly but when the data fetch success dispatch happens, the component is not seeing a change in state and subsequently not re rendering. the interesting part is that the first dispatch which sets a loading flag is being seen by the component and it is reacting correctly. Here is my code:
actions
import { programsConstants } from '../constants';
import axios from 'axios'
export const programsActions = {
begin,
success,
error,
};
export const loadPrograms = () => dispatch => {
dispatch(programsActions.begin());
axios
.get('/programs/data')
.then((res) => {
dispatch(programsActions.success(res.data.results));
})
.catch((err) => {
dispatch(programsActions.error(err.message));
});
};
function begin() {
return {type:programsConstants.BEGIN};
}
function success(data) {
return {type:programsConstants.SUCCESS, payload: data};
}
function error(message) {
return {type:programsConstants.ERROR, payload:message};
}
reducers
import {programsConstants} from '../constants';
import React from "react";
const initialState = {
data: [],
loading: false,
error: null
};
export function programs(state = initialState, action) {
switch (action.type) {
case programsConstants.BEGIN:
return fetchPrograms(state);
case programsConstants.SUCCESS:
return populatePrograms(state, action);
case programsConstants.ERROR:
return fetchError(state, action);
case programsConstants.EXPANDED:
return programsExpanded(state, action);
default:
return state
}
}
function fetchPrograms(state = {}) {
return { ...state, data: [], loading: true, error: null };
}
function populatePrograms(state = {}, action) {
return { ...state, data: action.payload, loading: false, error: null };
}
function fetchError(state = {}, action) {
return { ...state, data: [], loading: false, error: action.payload };
}
component
import React from "react";
import { connect } from 'react-redux';
import { Route, Switch, Redirect } from "react-router-dom";
import { Header, Footer, Sidebar } from "../../components";
import dashboardRoutes from "../../routes/dashboard.jsx";
import Loading from "../../components/Loading/Loading";
import {loadPrograms} from "../../actions/programs.actions";
class Dashboard extends React.Component {
constructor(props) {
super(props);
}
componentDidMount() {
this.props.dispatch(loadPrograms());
}
render() {
const { error, loading } = this.props;
if (loading) {
return <div><Loading loading={true} /></div>
}
if (error) {
return <div style={{ color: 'red' }}>ERROR: {error}</div>
}
return (
<div className="wrapper">
<Sidebar {...this.props} routes={dashboardRoutes} />
<div className="main-panel" ref="mainPanel">
<Header {...this.props} />
<Switch>
{dashboardRoutes.map((prop, key) => {
let Component = prop.component;
return (
<Route path={prop.path} component={props => <Component {...props} />} key={key} />
);
})}
</Switch>
<Footer fluid />
</div>
</div>
);
}
}
const mapStateToProps = state => ({
loading: state.programs.loading,
error: state.programs.error
});
export default connect(mapStateToProps)(Dashboard);
The component should receive updated props from the success dispatch and re render with the updated data. Currently the component only re renders on the begin dispatch and shows the loading component correctly but doesn't re render with the data is retrieved and updated to the state by the thunk.
I've researched this for a couple days and the generally accepted cause for the component not getting a state refresh is inadvertent state mutation rather than returning a new state. I don't think I'm mutating the state but perhaps I am.
Any help would much appreciated!
Update 1
As requested here's the code for creating the store and combining the reducers
store:
const loggerMiddleware = createLogger();
const composeEnhancers =
typeof window === 'object' &&
window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ ?
window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__({
}) : compose;
const enhancer = composeEnhancers(
applyMiddleware(
thunk,
loggerMiddleware)
);
export const store = createStore(rootReducer, enhancer);
reducer combine:
import { combineReducers } from 'redux';
import { alert } from './alert.reducer';
import { programs } from './programs.reducer';
import { sidenav } from './sidenav.reducer';
const rootReducer = combineReducers({
programs,
sidenav,
alert
});
export default rootReducer;
The 2nd param is expected to be [preloadedState]:
export const store = createStore(rootReducer, {} , enhancer);
axios.get return a promise that you need to await for to get your data:
Try this:
export const loadPrograms = () => async (dispatch) => {
dispatch(programsActions.begin());
try {
const res = await axios.get('/programs/data');
const data = await res.data;
console.log('data recieved', data)
dispatch(programsActions.success(data.results));
} catch (error) {
dispatch(programsActions.error(error));
}
};
const mapStateToProps = state => ({
loading: state.programs.loading,
error: state.programs.error,
data: state.programs.data,
});
Action Call
import React from 'react';
import { connect } from 'react-redux';
import { loadPrograms } from '../../actions/programs.actions';
class Dashboard extends React.Component {
componentDidMount() {
// Try to call you action this way:
this.props.loadProgramsAction(); // <== Look at this
}
}
const mapStateToProps = state => ({
loading: state.programs.loading,
error: state.programs.error,
});
export default connect(
mapStateToProps,
{
loadProgramsAction: loadPrograms,
},
)(Dashboard);
After three days of research and refactoring, I finally figured out the problem and got it working. Turns out that the version of react-redux is was using (6.0.1) was the issue. Rolled back to 5.1.1 and everything worked flawlessly. Not sure if something is broken in 6.0.1 or if I was just using wrong.
Currently I am trying to pass user data through my react app with Redux. I have created a user API with a django backend that is definately working, as I am able to go the url and see all the json that comes out of it. However, when I try to pass it into a component I keep getting undefined. Here is my code:
userActions.js:
import Axios from "axios";
export function getUser() {
const id = this.params.match.id
return dispatch => {
dispatch(fetchUserBegin());
return Axios.get(`/api/user/${id}`)
.then((res) => {
this.setState({
user: res.data,
})
})
}
}
export const FETCH_USER_BEGIN = 'FETCH_USER_BEGIN';
export const FETCH_USER_SUCCESS = 'FETCH_USER_SUCCESS';
export const FETCH_USER_FAILURE = 'FETCH_USER_FAILURE';
export const fetchUserBegin = () => ({
type: FETCH_USER_BEGIN
});
export const fetchUserSuccess = user => ({
type: FETCH_USER_SUCCESS,
payload: { user }
});
export const fetchUserFailure = error => ({
type: FETCH_USER_FAILURE,
payload: { error }
});
userReducer.js
import { FETCH_USER_BEGIN, FETCH_USER_SUCCESS, FETCH_USER_FAILURE } from '../actions/actionTypes'
const initialState = {
user: {},
loading: false,
error: null
};
export default function productReducer(state = initialState, action) {
switch(action.type) {
case FETCH_USER_BEGIN:
// Mark the state as "loading" so we can show a spinner or something
// Also, reset any errors. We're starting fresh.
return {
...state,
loading: true,
error: null
};
case FETCH_USER_SUCCESS:
// All done: set loading "false".
// Also, replace the items with the ones from the server
return {
...state,
loading: false,
user: action.user
};
case FETCH_USER_FAILURE:
// The request failed, but it did stop, so set loading to "false".
// Save the error, and we can display it somewhere
// Since it failed, we don't have items to display anymore, so set it empty.
// This is up to you and your app though: maybe you want to keep the items
// around! Do whatever seems right.
return {
...state,
loading: false,
error: action.payload.error,
user: {}
};
default:
// ALWAYS have a default case in a reducer
return state;
}
}
And the display component:
UserInformation.js:
import React from "react";
import { connect } from "react-redux";
import { getUser } from "../store/actions/userActions";
class UserDetailView extends React.Component {
componentDidMount() {
this.props.dispatch(getUser());
}
render() {
const { user } = this.props;
console.log(user)
return (
<ul>
{user.map(user =>
<li key={user.id}>{user.username}</li>
)}
</ul>
);
}
}
const mapStateToProps = state => ({
user: state.user,
});
export default connect(mapStateToProps)(UserDetailView);
Index.js
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';
import registerServiceWorker from './registerServiceWorker';
import { createStore, compose, applyMiddleware } from 'redux';
import { Provider } from 'react-redux';
import thunk from 'redux-thunk';
import reducer from './store/reducers/auth';
const composeEnhances = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose
const store = createStore(reducer, composeEnhances(
applyMiddleware(thunk)
))
const app = (
<Provider store={store}>
<App />
</Provider>
)
ReactDOM.render(app, document.getElementById('root'));
registerServiceWorker();
Anyone got any ideas why this isn't working?
You're not supposed to setState() in that action creator:
this.setState({
user: res.data,
})
you should dispatch an action instead
Try this:
export function getUser() {
const id = this.params.match.id
return dispatch => {
dispatch(fetchUserBegin());
return Axios.get(`/api/user/${id}`)
.then( res => {
dispatch(fetchUserSuccess(res.data);
})
}
}
You should pass the mapDispatchToProps function to the connect() method as the second argument, like this:
import React from "react";
import { connect } from "react-redux";
import { getUser } from "../store/actions/userActions";
class UserDetailView extends React.Component {
componentDidMount() {
this.props.getUser() //fixed
}
render() {
const { user } = this.props;
console.log(user)
return (
<ul>
{user.map(user =>
<li key={user.id}>{user.username}</li>
)}
</ul>
);
}
}
const mapStateToProps = state => ({
user: state.user,
});
const mapDispatchToProps = dispatch => ({ //added
getUser: dispatch(getUser())
})
export default connect(mapStateToProps,mapDispatchToProps)(UserDetailView); //fixed
And also fix this:
case FETCH_USER_SUCCESS:
// All done: set loading "false".
// Also, replace the items with the ones from the server
return {
...state,
loading: false,
user: action.payload.user //fixed
};
I am learning react-redux, so I decided to implement what I have been learning. But I am have a bug challenge. So I console.logged this.props.users from mapStateToProps function.
I believe there's something I not doing right which I don't understand. Please an explanation in other to move on. Thanks you so much for helping out.
Here is my code.
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { fetchUsers } from '../actions/userAction';
import UserList from '../components/UserList';
class UserPage extends Component {
constructor(props) {
super(props);
}
componentWillMount() {
this.props.fetchUsers();
}
componentDidMount() {
console.log(this.props.users);
}
render() {
return (
<div>
<h2>Users Page</h2>
<UserList users={this.props.users} />
</div>
);
}
}
const mapStateToProps = state => {
return {
users: state.userReducer.users
};
};
const mapDispatchToProps = dispatch => {
return {
fetchUsers: () => dispatch(fetchUsers())
};
};
export default connect(mapStateToProps, mapDispatchToProps)(UserPage);
So this is what I get from the chrome console - Empty arrays.
props showing empty arrays
But when I check the React DevTool and Redux DevTool, they display the expected Props and States respectively. Below are the snapshot of the dev tools
React devtool shows the correct Props
Redux devtool show the correct States and Actions
userAction.js
import axios from 'axios';
import * as types from './actionTypes';
export let fetchingUser = () => {
return {
type: types.FETCHING_USERS
};
};
export let fetchedUser = payload => {
return {
type: types.FETCHED_USER,
payload
};
};
export let fetchUser_error = () => {
return {
type: types.FETCH_USER_ERROR
};
};
export let fetchUsers = () => {
let url = 'https://eventcity.herokuapp.com/api/v1/users';
return dispatch => {
dispatch(fetchingUser());
return axios
.get(url)
.then(response => {
const users = response.data.data;
dispatch(fetchedUser(users));
})
.catch(err => {
dispatch(fetchUser_error());
});
};
};
userReducer.js
import * as types from '../actions/actionTypes';
import initialState from './initialState';
const userReducer = (state = initialState, action = {}) => {
switch (action.type) {
case types.FETCHING_USERS:
return { ...state, users: [], error: null, loading: true };
case types.FETCHED_USER:
return { ...state, users: action.payload, error: null, loading: false };
case types.FETCH_USER_ERROR:
return {
...state,
users: [],
error: { message: 'Error loading data from the API' },
loading: false
};
default:
return state;
}
};
export default userReducer;
configureStore.js
import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import { composeWithDevTools } from 'redux-devtools-extension';
import rootReducer from '../reducer/rootReducer';
const configureStore = () => {
return createStore(rootReducer, composeWithDevTools(applyMiddleware(thunk)));
};
export default configureStore;
rootReducer.js
import { combineReducers } from 'redux';
import userReducer from './userReducer';
const rootReducer = combineReducers({
userReducer
});
export default rootReducer;
I think you might want to check this
https://github.com/reactjs/react-redux/issues/129. Your problem is using componentDidMount and componentWillMount without having a better understanding of what they are used for.
The problem is not with redux, all you need to understand is that your fetchUsers request is async and componentDidMount function is only executed once after the component has rendered and it may so happen that the data is not present by the time componentDidMount function is executed and hence your console.log(this.props.users); return empty array, Log it in the render method and you will see the correct data
class UserPage extends Component {
constructor(props) {
super(props);
}
componentWillMount() {
this.props.fetchUsers();
}
render() {
console.log(this.props.users);
return (
<div>
<h2>Users Page</h2>
<UserList users={this.props.users} />
</div>
);
}
}