I'm a bit new to using redux and react. I'm trying to make a simple API call with redux and having it render in react. I can see the API call working as it's in the payload in redux dev tools, but I can't seem to get it to update the state possibly in the `connect?.
actions/index
import FilmAPI from '../api/api';
export const FETCH_FILMS = 'FETCH_FILMS';
export const RECEIVE_FILMS = 'RECEIVE_FILMS';
export const receiveFilms = (films) => {
return {
type: RECEIVE_FILMS,
films
};
}
export const fetchFilmsRequest = () => {
return dispatch => {
return axios.get('https://www.snagfilms.com/apis/films.json?limit=10')
.then(response => {
dispatch(receiveFilms(response.data))
})
}
}
export default fetchFilmsRequest;
reducers/FilmReducer
import RECEIVE_FILMS from '../actions/index';
export function films (state = [], action) {
switch (action.type) {
case RECEIVE_FILMS:
return [...state, action.films];
default:
return state;
}
}
reducers/index
import { combineReducers } from 'redux';
import { films } from './FilmsReducer';
export default combineReducers({
films,
});
containers/FilmListContainer
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { fetchFilmsRequest } from '../actions';
import FilmList from '../components/FilmList'
class FilmListContainer extends Component {
constructor(props) {
super(props);
}
componentWillMount() {
this.props.fetchFilmsRequest();
}
render() {
return (
<div>
<FilmList films={this.props.films}/>
</div>
);
}
}
const mapStateToProps = state => ({
films: state.films
})
export default connect(mapStateToProps, {fetchFilmsRequest: fetchFilmsRequest})(FilmListContainer);
configureStore.js
import { createStore, compose, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import rootReducer from '../reducers';
export default function configureStore(initialState) {
const composeEnhancers =
window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ ?
window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__({
// options like actionSanitizer, stateSanitizer
}) : compose;
const enhancer = composeEnhancers(
applyMiddleware(thunk)
);
return createStore(
rootReducer,
initialState,
enhancer
);
}
As mentioned, Redux DevTools show the films in the payload, but films still remain 0 in its state. Could anyone please point me in the right direction?
You can get updated state by subscribing store and use store.getState()
Steps:
Write subscribe function in constructor of component class.
Set state of class by store.getState().
import store from '../js/store/index';
class MyClass extends Component {
constructor(props, context) {
super(props, context);
this.state = {
classVariable: ''
}
store.subscribe(() => {
this.setState({
classVariable: store.getState().MyStoreState.storeVariable
});
});
}
}
You are close, your action needs to send the data to the store by dispatching an event which your reducer can then catch. This is done using the type attribute on the dispatch object.
https://redux.js.org/basics/actions
return fetch('https://www.snagfilms.com/apis/films.json?limit=10')
.then(response => {
dispatch({
type: RECEIVE_FILMS,
payload: response,
})
})
You then need to grab the data in your reducer and put it in the store
export function films (state = [], action) {
switch (action.type) {
case RECEIVE_FILMS:
return {
...state,
films: action.payload.films
};
default:
return state;
}
}
It looks like you just need to import your action type constant into your reducer using a named import instead of a default export.
i.e. import {RECEIVE_FILMS} from '../actions' rather than import RECEIVE_FILMS from '../actions'
Just dispatch result of resolved fetch promise like so:
if the payload is json, then:
export const fetchFilmsRequest = () => {
return dispatch => {
return fetch('https://www.snagfilms.com/apis/films.json?limit=10')
.then(response => response.json())
.then(response => {
dispatch({
type: RECEIVE_FILMS,
payload: response
})
})
}
Your reducer would need modifying slightly to:
export function films (state = [], action) {
switch (action.type) {
case RECEIVE_FILMS:
return [...action.payload]; // assuming response is jus array of films
default:
return state;
}
}
Related
I'm trying pass the data from reducer to component and receive as props.
But the data return UNDEFİNED, so I have tried console the data on reducer and action, but it's okey. There isn't any problem with the data coming from the API, but it always return to component undefined. Where is my fault?
Action
export default ProfileTab;
import axios from 'axios';
import { BASE, API_KEY } from '../config/env';
export const FETCHED_MOVIES = 'FETCHED_MOVIES';
export function fetchMovies() {
return (dispatch) => {
axios
.get(`${BASE}s=pokemon&apikey=${API_KEY}`)
.then((result) => result.data)
.then((data) =>
dispatch({
type: FETCHED_MOVIES,
payload: data.Search,
}),
);
};
}
Reducer
import { FETCHED_MOVIES } from '../actions/movies';
const initialState = {
fetching: false,
fetched: false,
movies: [],
error: {},
};
export default (state = initialState, action) => {
switch (action.type) {
case 'FETCHED_MOVIES':
return {
...state,
movies: action.payload,
};
default:
return state;
}
};
Component
import React, { Component } from 'react';
import { connect } from 'react-redux';
import PropTypes from 'prop-types';
import { fetchMovies } from '../../actions/movies';
class Case extends Component {
static propTypes = {
movies: PropTypes.object.isRequired,
};
constructor(props) {
super(props);
}
componentDidMount() {
this.props.fetchMovies();
}
onChangeHandler = (e) => {
this.setState({
input: e.target.value,
});
};
render() {
console.log(this.props.movies);
return (
<div>
<div className="movies-root">
<div className="movies-wrapper">
<div className="movies-container safe-area">
<h1>mert</h1>
</div>
</div>
</div>
</div>
);
}
}
const mapStateToProps = (state) => {
return {
movies: state.movies,
};
};
const mapDispatchToProps = {
fetchMovies,
};
export default connect(mapStateToProps, mapDispatchToProps)(Case);
Do this in the connect statement:
export default connect(mapStateToProps,{fetchMovies})(Case);
And remove the mapDispatchToProps function from your code.
Dispatching props as an object is quite incorrect. Try this, and it should work.
That's because your mapDispatchToProps function should return an object and take dispatch as parameter. Each field in your returned object should contain a function that dispatches your action.
So try something like this:
const mapDispatchToProps = dispatch => {
return {
fetchMovies: () => dispatch(fetchMovies())
}
}
Although there's already an accepted answer, I'm not sure how correct it is, as it's completely valid to pass mapDispatchToProps the way you did with the latest react (16.13.1) and react-redux (7.2.1) versions (I'm not sure about earlier versions).
Now, assuming your question contains the whole code, there are two important things missing:
Creating the store:
import { createStore } from "redux";
const store = createStore(reducer);
and passing it to the Provider component:
<Provider store={store}>
If you go ahead and do as above, you'll see that this.props.fetchMovies emits the following error:
Actions must be plain objects. Use custom middleware for async actions.
To fix it, do as it says and add a middleware, e.g. thunk:
import { createStore, applyMiddleware } from "redux";
import thunk from "redux-thunk";
const store = createStore(rootReducer, applyMiddleware(thunk));
What follows is the full code. Note that I "split" fetchMovies into two functions: sync and async, for illustrating the difference usage between the two. I also modified your code (made is shorter, mostly) for this answer's readability. You can also see a live demo here:
File app.js
import React, { Component } from "react";
import { connect } from "react-redux";
import { fetchMoviesSync, fetchMoviesAsyncMock } from "./api";
class App extends Component {
componentDidMount() {
this.props.fetchMoviesSync();
this.props.fetchMoviesAsyncMock();
}
render() {
return (
<div>
<div className="movies-root">
<div className="movies-wrapper">
<div className="movies-container safe-area">
{this.props.movies.join("\n")}
</div>
</div>
</div>
</div>
);
}
}
const mapStateToProps = (state) => ({ movies: state.movies });
const mapDispatchToProps = {
fetchMoviesSync,
fetchMoviesAsyncMock
};
export default connect(mapStateToProps, mapDispatchToProps)(App);
File api.js
export const FETCHED_MOVIES = "FETCHED_MOVIES";
export const fetchMoviesSync = () => ({
type: FETCHED_MOVIES,
payload: ["movie1", "movie2", "movie3", "movie4"]
});
export const fetchMoviesAsyncMock = () => (dispatch) => {
dispatch({
type: FETCHED_MOVIES,
payload: ["movie5", "movie6", "movie7", "movie8"]
});
};
File reducer.js
const initialState = {
movies: [],
};
export default (state = initialState, action) => {
switch (action.type) {
case "FETCHED_MOVIES":
return {
...state,
movies: state.movies.concat(action.payload)
};
default:
return state;
}
};
File index.js
import React from "react";
import ReactDOM from "react-dom";
import Case from "./app";
import reducer from "./reducer";
import { createStore, applyMiddleware } from "redux";
import { Provider } from "react-redux";
import thunk from "redux-thunk";
let store = createStore(reducer, applyMiddleware(thunk));
ReactDOM.render(
<Provider store={store}>
<Case />
</Provider>,
document.getElementById("container")
);
File index.html
<body>
<div id="container"></div>
</body>
Hello i begin in react redux i try to play with an api my problem is at begining in my idea i hope make a select and in the select all the results for a day:
My Component ResultListItems:
import { connect } from 'react-redux';
import { fetchResults } from "../actions/index";
class ResultListItems extends Component {
componentWillMount(){
this.props.fetchResults();
}
render() {
return (
<div>
<h2>Coucou la liste resultats</h2>
<select></select>
</div>
);
}
}
const mapStateToProps = (state) => {
return {
results: state.resultsReducer.results
};
};
export default connect(mapStateToProps, null)(ResultListItems)
My Action in index.js in folder actionsat this moment i have a date in url
import axios from "axios";
export const GET_RESULTS = "GET_RESULTS";
const END_POINT = "http://data.nba.net/10s/20200203";
export function fetchResults() {
return function(dispatch) {
axios.get(`${END_POINT}`)
.then(axiosResponse => {
dispatch({ type: GET_RESULTS, payload: axiosResponse.data});
});
}
}
My reducer => reducer_results :
const initialResults ={
results: []
}
export default function (state = initialResults, action) {
switch (action.type) {
case GET_RESULTS:
return {
results: action.payload
};
}
return state
}
I import in index.js in reducer Folder:
import ReducerResults from "../reducers/reducer_results";
const rootReducer = combineReducers({
resultsReducer: ReducerResults
});
export default rootReducer;
And my container is results.js :
import { connect } from 'react-redux';
import ResultListItems from '../components/results_list_item'
class Results extends Component {
render() {
return (
<div>
<h1>App NBA</h1>
<ResultListItems />
</div>
);
}
}
export default connect()(Results);
You are not mapping your api call of fetchResults to props.Try the following. After mapping state to props, map dispatch as well to props in component ResultListItems.
const mapDispatchToProps = (dispatch, ownProps) => {
return {
fetchResults : () => dispatch(fetchResults()),
dispatch
}
}
then coonect it like this.
export default connect(mapStateToProps, mapDispatchToProps)(ResultListItems)
So, you haven't fetchResults in the list of props, this.props.fetchResults is undefined, because you haven't binded the action to the component's props. To deal with it you need to bind the actionCreator. Use a guide: https://blog.benestudio.co/5-ways-to-connect-redux-actions-3f56af4009c8
Or
just do like that:
componentWillMount(){
const {dispatch} = this.props;
dispatch(fetchResults());
}
I'm using React-Laravel for my project.
The problem is when I tried to use redux-thunk for the asynchronous dispatch function.
My dispatch function won't get executed.
Please do help me figure out this problem.
I have already tried to use promise or redux-devtools-extension library
https://codeburst.io/reactjs-app-with-laravel-restful-api-endpoint-part-2-aef12fe6db02
app.js
import React from 'react';
import ReactDOM from 'react-dom';
import { BrowserRouter } from 'react-router-dom';
import { createStore, combineReducers, applyMiddleware, compose } from 'redux';
import { Provider } from 'react-redux';
import thunk from 'redux-thunk';
import logger from 'redux-logger';
import Layout from './jsx/Layout/Layout';
import marketplaceReducer from './store/reducers/marketplace';
const composeEnhancers = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;
const appReducer = combineReducers({
marketplace: marketplaceReducer
});
const rootReducer = (state, action) => {
return appReducer(state, action);
}
const store = createStore(rootReducer, composeEnhancers(
applyMiddleware(logger, thunk)
));
const render = (
<Provider store={store}>
<BrowserRouter>
<Layout />
</BrowserRouter>
</Provider>
);
ReactDOM.render(render, document.getElementById('root'));
marketplace.js (action)
import * as actionTypes from './actionTypes';
import axios from '../../axios';
export const loadMarketplace = () => {
console.log("Load Marketplace");
return {
type: actionTypes.LOAD_MARKETPLACE
};
}
export const successMarketplace = (data) => {
console.log("Success Marketplace");
return {
type: actionTypes.SUCCESS_MARKETPLACE,
data: data
}
}
export const failedMarketplace = () => {
console.log("Failed Marketplace");
return {
type: actionTypes.FAILED_MARKETPLACE
}
}
export const showMarketplace = () => {
console.log("Show Marketplace Action")
return dispatch => {
//This is the problem
//Inside this function, I can't see any console.log, even loadMarketplace() didn't get called.
console.log("Show Marketplace in dispatch");
dispatch(loadMarketplace());
axios.get('/marketplaces')
.then(response => {
dispatch(successMarketplace(response));
})
.catch(error => {
dispatch(failedMarketplace());
});
};
}
marketplace.js (reducer)
import * as actionTypes from '../actions/actionTypes';
const initial_state = {
data: [],
loading: false
}
const loadMarketplace = (state, action) => {
console.log("Load Marketplace Reducer")
return {
...state,
loading: true
};
}
const successMarketplace = (state, action) => {
console.log("Success Marketplace Reducer", action.data)
return {
...state,
loading: false,
data: action.data
};
}
const failedMarketplace = (state, action) => {
return {
...state,
loading: false
};
}
const reducer = (state = initial_state, action) => {
//This is called when the first init, never got it through showMarketplace() function.
console.log("Marketplace Reducer", action);
switch (action.type) {
case actionTypes.LOAD_MARKETPLACE: return loadMarketplace(state, action);
case actionTypes.SUCCESS_MARKETPLACE: return successMarketplace(state, action);
case actionTypes.FAILED_MARKETPLACE: return failedMarketplace(state, action);
default: return state;
}
}
export default reducer;
Marketplace.js (jsx view)
import React, { Component } from 'react';
import { connect } from 'react-redux';
import * as actions from '../../../store/actions';
class Marketplace extends Component {
componentDidMount() {
console.log('[ComponentDidMount] Marketplace')
this.props.showMarketplace();
}
render() {
return (
<React.Fragment>
Marketplace
</React.Fragment>
);
}
}
const mapDispatchToProps = dispatch => {
return {
showMarketplace: () => dispatch(actions.showMarketplace)
};
}
export default connect(null, mapDispatchToProps)(Marketplace);
This is the result of my console.log (when loading the first time for Marketplace.js)
Please do help, I've been struggling for 2 hours or more, only because of this problem. (This is my first time using React-Laravel).
Thank you.
I already found the problem. It is not redux-thunk problem.
It is actually a normal Redux problem we found anywhere.
Marketplace.js (jsx view)
import React, { Component } from 'react';
import { connect } from 'react-redux';
import * as actions from '../../../store/actions';
class Marketplace extends Component {
componentDidMount() {
console.log('[ComponentDidMount] Marketplace')
this.props.showMarketplace();
}
render() {
return (
<React.Fragment>
Marketplace
</React.Fragment>
);
}
}
const mapDispatchToProps = dispatch => {
return {
showMarketplace: () => dispatch(actions.showMarketplace) //THIS IS THE PROBLEM, IT IS NOT EXECUTING PROPERLY. THIS ONE SHOULD BE
showMarketplace: () => dispatch(actions.showMarketplace()) //SHOULD BE LIKE THIS.
};
}
export default connect(null, mapDispatchToProps)(Marketplace);
Edited: I think it is something about thunk is not added right to redux.
First of all try to add only thunk.
const store = createStore(rootReducer, composeEnhancers(
applyMiddleware(thunk)
));
If it works, maybe try to change the order of them.
I'm developing a react-redux app and I can get access to the reducers via routes. Now I'm facing the trouble of getting access to a specific reducer without using routes.
Here is my reducers.js:
const initialState = {
loading: false,
topics: []
};
export default createReducer(initialState, {
[LOADING_DATA]: (state, action) => {
return Object.assign({}, state, {
loading: action.loading
});
}
});
This is my actions.js:
export function loading (loading) {
return {
type: LOADING_DATA,
payload: {loading}
};
}
And this is what I have on my component:
import {connect} from 'react-redux'
import {bindActionCreators} from 'redux';
import * as moduleActionCreators from '...';
import * as actionCreators from '...';
class MyComponent extends Component {
...
render () {
return (<div>
...
</div>;
}
}
const mapStateToProps = (state) => ({
});
const mapDispatchToProps = (dispatch) => ({
actions: bindActionCreators(Object.assign({}, moduleActionCreators, actionCreators), dispatch)
});
export default connect(mapStateToProps, mapDispatchToProps)(MyComponent);
Normally in the mapStateToProps I reference the reducer variables as loading: state['my_reference_to_reducer'].loading but I can't figure it out how to tell the component to reference my reducers.js in order to get loading as props.
I would appreciate a light on this.
You need to set up the state in mapStateToProps function in order to access it:
const mapStateToProps = (state) => {
return {
loading: state.loading
}
}
Then you should be able to use it as this.props.loading in MyComponent.
Your reducer can look like this:
export default function reducer(state = {}, action) {
switch(action.type) {
case 'LOADING_DATA':
return Object.assign({}, state, {
...state,
loading: action.payload.loading
})
I recommend you to use redux ducks pattern as it keeps action creators and reducers at the same file, saves you time and makes it easier to read and use. For example:
loading.js
// Actions
const LOADING_DATA = 'LOADING_DATA'
// Action Creators
export const loadingData = (data) => {
return {
type: LOADING_DATA,
payload: {
loading: data
}
}
}
// Reducer
export default function reducer(state = {
loading: 'DATA zeroed'
}, action) {
switch(action.type) {
case 'LOADING_DATA':
return Object.assign({}, state, {
...state,
loading: action.payload.loading
})
default:
return state
}
}
index.js
import React from 'react';
import ReactDOM from 'react-dom';
import MyComponent from './MyComponent';
import configureStore from './configureStore'
const store = configureStore()
ReactDOM.render(
<MyComponent store={store}/>,
document.getElementById('root')
);
configureStore.js
import { createStore } from 'redux'
import { composeWithDevTools } from 'redux-devtools-extension'
import loadingData from './loading'
const configureStore = () => {
return createStore(loadingData, composeWithDevTools())
}
export default configureStore
MyComponent.js
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { loadingData } from './loading';
class MyComponent extends Component {
constructor(props){
super(props)
this.onLoadingData = this.onLoadingData.bind(this)
}
componentDidMount() {
this.props.loadingData('no more undefined')
}
onLoadingData() {
this.props.loadingData('DATA')
}
render() {
console.log(this.props.loading)
return (
<div>
<h2>MyComponent</h2>
<button onClick={this.onLoadingData}>Load Data</button>
<p>{this.props.loading}</p>
</div>
);
}
}
const mapStateToProps = (state) => {
return {
loading: state.loading
}
}
const mapDispatchToProps = {
loadingData
}
export default connect(
mapStateToProps,
mapDispatchToProps
)(MyComponent)
Could someone please help me with this problem?
I've started to learn React and Redux but I'm stuck from a couple of days on configuring redux.
I'm assuming that when something triggers an action, redux through the reducers stack of functions should return an object that represents my application state.
Unfortunately, It returns an object with { reducerName => reducer result } basically means that if I've 4 reducers, the function store.getState() returns something like
{
'reducerOne': entireApplicationState
'reducerTwo': entireApplicationState
'reducerThree': entireApplicationState
'reducerFour': entireApplicationState
}
I'll really appreciate if someone can help me because I've finished all the ideas :)
This is my application.js:
import React from 'react';
import ReactDom from 'react-dom';
import HomePage from 'root_views/home';
import {store} from 'root_services/redux/store';
class Application extends React.Component {
constructor(props) {
super(props);
}
render() {
return (
<HomePage/>
)
}
}
var Provider = React.createClass({
childContextTypes: {
store: React.PropTypes.object.isRequired
},
getChildContext: function () {
return {store: this.props.store}
},
render: function () {
return this.props.children;
}
});
ReactDom.render(
<Provider store={store}>
<Application/>
</Provider>,
document.getElementById('application')
);
My store.js
import { createStore } from 'redux';
import {rootReducer} from './reducers/container';
export const store = createStore(
rootReducer,
window.__REDUX_DEVTOOLS_EXTENSION__ && window.__REDUX_DEVTOOLS_EXTENSION__()
);
My container.js that basically contains all my reducers
import {combineReducers} from 'redux';
// This is just the action label
import {DATA_EXCHANGE_LOAD} from 'root_services/redux/actions/container'
const initialState = {
data_exchange: {},
}
function dataExchange(state = {}, action) {
switch (action.type) {
case DATA_EXCHANGE_LOAD:
return Object.assign({}, state, {
data_exchange:{'reducerOne':'dataExchange'}
});
break;
default:
return initialState;
break;
}
};
function testReducer(state = {}, action) {
switch (action.type) {
case DATA_EXCHANGE_LOAD:
return Object.assign({}, state, {
data_exchange:{'reducerTwo':'testReducer'}
});
break;
default:
return initialState;
break;
}
};
// Export the combined reducers
export const rootReducer = combineReducers({
dataExchange,
testReducer
});
This is the action that triggers the event:
export function dataExchangeLoad(){
return {
type: DATA_EXCHANGE_LOAD,
}
};
This is my component where the action is triggered:
import React from 'react'
import "../components/layouts/header/header.less";
import {dataExchangeLoad} from "root_services/redux/actions/container"
export default class HomePage extends React.Component {
constructor(props, {store}) {
super(props);
store.dispatch(dataExchangeLoad());
console.log(store.getState());
}
render() {
return (
<div>
<h1>test</h1>
</div>
)
}
};
HomePage.contextTypes = {
store: React.PropTypes.object,
}
This is the result:
Object {dataExchange: Object, testReducer: Object}
As was already answered in comments combineReducers indeed works that way. In case you want to chain reducers so that action will go through all of them sequentially updating state in each one you can use reduce-reducers. Using this helper function it's possible to do something like that (looks like that is what you want to achieve):
import reduceReducers from 'reduce-reducers';
const reducer1 = (state = {}, action) => {
if (action.type === 'foo') {
return ({
...state,
touchedBy: ['reducer1'],
})
}
return state;
};
const reducer2 = (state = {}, action) => {
if (action.type === 'foo') {
return ({
...state,
touchedBy: state.touchedBy.concat('reducer2'),
})
}
return state;
};
const reducer = reduceReducers(reducer1, reducer2);
expect(reducer({}, { type: 'foo' }))
.toMatchObject({ touchedBy: ['reducer1', 'reducer2'] });
In case anyone is looking, the link provided above in the comments is broken. This link works and explains well how to rename the state coming from your reducers. If you don't want to read, rename your reducer import or rename it inside your combineReducer.
Example1:
import billReducer as billState from "./reducers";
Example2:
const rootReducer = combineReducer({billState: billReducer});
Using combineReducers