I'm just starting with React and Redux and stumbled upon something I can't figure out by myself - I think that Redux state is not changing and it's causing (some of) errors. I'm checking state with use of remote-redux-devtools#0.5.0.
My code:
Categories.js:
import React, { Component } from 'react';
import { connect } from 'react-redux';
import PropTypes from 'prop-types';
import { getCategories } from '../../actions/categories';
export class Categories extends Component {
static propTypes = {
categories: PropTypes.array.isRequired
};
componentDidMount() {
this.props.getCategories();
}
render() {
return (
<div>
Placeholder for categories.
</div>
)
}
}
const mapStateToProps = state => ({
categories: state.categories.categories
});
export default connect(mapStateToProps, { getCategories })(Categories);
../../actions/categories.js:
import axios from "axios";
import { CATEGORIES_GET } from "./types";
export const getCategories = () => dispatch => {
return axios
.get("/api/notes/categories/")
.then(res => {
dispatch({
type: CATEGORIES_GET,
payload: res.data
});
})
.catch(err => console.log(err));
};
reducers/categories.js:
import { CATEGORIES_GET } from '../actions/types.js';
const initialState = {
categories: []
};
export default function (state = initialState, action) {
switch (action.type) {
case CATEGORIES_GET:
return {
...state,
categories: action.payload
};
default:
return state;
}
}
store.js:
import { createStore, applyMiddleware } from 'redux';
import { composeWithDevTools } from 'remote-redux-devtools';
import thunk from 'redux-thunk';
import rootReducer from './reducers';
const initialState = {};
const middleware = [thunk];
const store = createStore(
rootReducer,
initialState,
composeWithDevTools(applyMiddleware(...middleware)));
export default store;
reducers/index.js
import { combineReducers } from "redux";
import categories from './categories';
export default combineReducers({
categories,
});
Using remote-redux-devtools, I've never seen anything in my state. Currently this code above gives me 3 errors, two of them being
this.props.getCategories is not a function
My guess is that because there is some issue with Categories class, it's not passing anything to state and it could be root cause of errors. I had one more error, connected to Categories not being called with attributes, but for debug purposes I put empty array there - one error dissapeared, but that's it. I've also tried adding constructor to Categories and called super(), but did not help also.
I believe your issue is that you're exporting your Categories class twice, once connected, the other not.
If you remove export from export class Categories extends Component, does it work as expected?
When you're mapping the state in a component, you must access the desired variable through a reducer.
So instead of:
const mapStateToProps = state => ({
categories: state.categories
});
You must use:
const mapStateToProps = state => ({
categories: state.categories.categories
});
Your props don't have getCategories method, because you didn't pass it as a function to connect.
A better approach is to define only the action code in your actions file and then use mapDispatchToProps.
../../actions/categories.js
import axios from "axios";
export const getCategories = () => {
axios
.get("/api/notes/categories/")
.then(res => res.data);
})
.catch(err => console.log(err));
};
Categories.js
import { getCategories } from '../../actions/categories'
import { CATEGORIES_GET } from "./types";
const mapDispatchToProps = dispatch => {
return {
getCategories: () => dispatch(() => { type: CATEGORIES_GET, payload: getCategories() }),
}
}
export default connect(mapStateToProps, mapDispatchToProps)(Categories);
Related
I am simply trying to connect() my LoginPage (component) to my Redux Store and dispatch in action via a onClick (event). When I console.log(this.props) my dispatch handler login() isn't in the component's props.
GitHub Repo -- https://github.com/jdavis-software/demo.git
Question: Why isn't my Redux Store either connection or dispatching the actions?
LoginPage:
import React, { Component} from 'react';
import { connect } from 'react-redux';
export class LoginPage extends Component<any> {
render(){
console.log('props doesnt have contain - login(): ', this.props)
return (<button onClick={ () => '' }>Login</button>)
}
}
const mapProps = state => ({ user: state.user })
const dispatchProps = (dispatch) => {
return {
login: () => dispatch({ type: 'USER_LOGGED_IN', payload: true})
}
}
export default connect(mapProps,dispatchProps)(LoginPage)
Redux Configuration:
import { IStore, IUser } from '#interfaces';
import { createStore, combineReducers } from 'redux';
import ReduxPromise from 'redux-promise';
// reducers
import userReducer from './user.reducer';
// define the intial global store state
const initialState:IStore = {
user: {
isAuthenticated: false
}
}
const appReducer = combineReducers({user: userReducer})
export default createStore(appReducer,initialState);
User Reducer:
// initial state
const initalState:IUser = {
isAuthenticated: false
}
// reducer
const userReducer = (state:IUser = initalState, { type, payload}: IPayload): IUser => {
console.log('user reducer start', state)
switch (type) {
case 'USER_LOGGED_IN':
state = { ...state, isAuthenticated: payload }
break;
default:
return state;
}
return state;
};
export default userReducer;
Root Page:
import React from 'react';
import { render } from 'react-dom';
import { Provider } from 'react-redux';
// styles
import './index.scss';
// pages
import { App } from '#pages';
// store
import store from './core/store/store';
render(
<Provider store={store}>
<App/>
</Provider>, document.getElementById('app')
);
I checked your code on git repository. I found out that you're exporting the named export
export class LoginPage
and the default export,
export default connect(mapProps,dispatchProps)(LoginPage)
But when you're accessing it, you're accessing it as
import { /*Other components*/ , LoginPage } from '#pages'
So it is actually taking the named exported component which is not connected to store.
I suggest you to import as
import LoginPage , { /*Other components*/ } from '#pages'
This might solve your problem.
Return statements are missing in the properties of connect.
const mapProps = state => { return {user: state.user} }
const dispatchProps = (dispatch) => {
return {
login: () => dispatch({ type: 'USER_LOGGED_IN', payload: true})
}
}
export default connect(mapProps,dispatchProps)(LoginPage)
Updated:
Please check Redux-dispatch
try:
import React, { Component} from 'react';
import { connect } from 'react-redux';
export class LoginPage extends Component<any> {
render(){
console.log('props doesnt contain - login(): ', this.props)
return (
<button onClick={ this.props.login }>Login</button>
)
}
}
const mapProps = state => ({ user: state.user })
const dispatchProps = (dispatch) => ({
login: () => dispatch({ type: 'USER_LOGGED_IN', payload: true})
})
export default connect(mapProps,dispatchProps)(LoginPage)
to return an object with Arrow Functions you need to wrap your {} with ()
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).
I've created a react app using create-react-app and react-redux. I dispatch an action using mapDispatchToProps on clicking a button and it returns a payload. But when I try to retrieve the props using mapStateToProps in my component, it returns the initial state.
What am I doing wrong?
I have tried to debug thoroughly and I realize that the action is dispatched and the payload makes it to the action creator. But the reducer isn't triggered after the action is dispatched.
It might be how I am calling it or how I have set up my reducer as well.
index.js file:
import React from 'react';
import './css/index.css';
import App from './App/App';
import * as serviceWorker from './serviceWorker';
import { render } from 'react-dom';
import { Provider } from 'react-redux';
import { createStore, applyMiddleware } from 'redux';
import rootReducer from './reducers';
import thunk from 'redux-thunk';
const store = createStore(rootReducer, applyMiddleware(thunk));
render(
<Provider store={store}>
<App />
</Provider>,
document.getElementById('root')
)
reducers/Reducer.js
reducers/Reducer.js
import { GET_RESP } from '../modules/actions'
function getInitialState () {
return {
predictions: [],
score: null
}
}
function gesResp (state, payload) {
return {
...state,
predictions: payload.predictions,
score: payload.score
}
}
export function Reducer (state, action) {
if (!state) {
return getInitialState();
}
switch(action.type) {
case GET_RESP:
return gesResp(state, action.payload);
default:
return state;
}
}
export default Reducer;
reducers/index.js
import { combineReducers } from 'redux';
import Reducer from './Reducer'
const rootReducer = combineReducers({
Reducer
});
export default rootReducer;
action.js
import axios from 'axios';
// actions:
export const GET_RESP = 'GET_RESP';
// action creators:
export function gesResp (payload) {
return {
type: GET_RESP,
payload: payload
}
}
export function fetchRecommendations (description, resp) {
let url = 'myendpointurl';
let requestPayload = {
description: description,
resp: resp
}
return (dispatch) => {
return axios.post(url, requestPayload)
.then(function(res) {
gesResp(res.data);
})
}
}
component file: (I'm only posting related code):
handleSubmit () {
this.props.fetchMyRecommendations(Desc,
this.state.htmlContent);
}
const mapStateToProps = state => {
return {
predictions: state.Reducer.predictions,
score: state.Reducer.score
};
}
const mapDispatchToProps = dispatch => {
return {
fetchMyRecommendations: (Desc, userScore) =>
dispatch(fetchRecommendations(Desc, userScore))
};
}
export default connect(mapStateToProps, mapDispatchToProps)
(HomePage);
Ideally what I want is in the mapStateToProps to return the predictions array and the resp score.
I can see that they are being returned in the network call and showing up the actions call as well. Thanks in advance to whoever can help! :)
You need to dispatch getReccommendations to actually trigger the reducer for your asynchronous action. Try the following:
export function fetchRecommendations (job_description, resume) {
let url = 'myendpointurl';
let requestPayload = {
job_description: job_description,
resume: resume
};
return (dispatch) => {
return axios.post(url, requestPayload)
.then(function(res) {
dispatch(getReccommendations(res.data));
});
}
}
Hopefully that helps!
I'm new to React, please keep this in mind.
I'm trying to render a list of recipes fetched from food2fork API but I can't get the view to update, even if the data is fetched correctly.
Here's recipe_list.js:
import React, { Component } from "react";
import { connect } from "react-redux";
class RecipesList extends Component {
// renderRecipe(recipe) {
// console.log(recipe);
// return (
// <div>{recipe}</div>
// );
// }
render() {
console.log("Render function ", this.props.recipes)
return (
<div>
<p>Recipes</p>
<div>{this.props.recipes}</div>
</div>
);
}
}
function mapStateToProps(state){
return { recipes: state.recipes };
}
export default connect(mapStateToProps)(RecipesList);
Here's reducer_recipes.js:
import FETCH_RECIPES from "../actions/index";
export default function(state = [], action){
switch (action.type) {
case FETCH_RECIPES:
return action.payload;
}
return state;
}
Here's /reducers/index.js:
import { combineReducers } from 'redux';
import RecipesReducer from "./reducer_recipes";
console.log(RecipesReducer);
const rootReducer = combineReducers({
recipes: RecipesReducer
});
export default rootReducer;
Here's /actions/index.js:
import axios from "axios";
const API_KEY = "****************************";
export const URL = `https://food2fork.com/api/search?key=${API_KEY}`;
export const FETCH_RECIPES = "FETCH_RECIPES";
export function fetchRecipes(term){
const url = `${URL}&q=${term}`;
const request = axios.get(url);
return {
type: FETCH_RECIPES,
payload: request
};
}
I don't get any specific error. The view just doesn't update. I tried to spread some console.log around the files to try to understand where the problem is.
It seems like the Reducer is not successfully delivering the payload to the component.
NOTE: I'm using react-promise so the promise returned from axios is automatically resolved.
Any ideas?
===================================================================
EDIT:
Thank you for the useful links but there is clearly something that I'm still missing here.
I have modified the action index:
function getStuffSuccess(response) {
return {
type: FETCH_RECIPES,
payload: response
};
}
function getStuffError(err) {
return {
type: ERROR_FETCH_RECIPES,
payload: err
};
}
export function fetchRecipes(term) {
const url = `${URL}&q=${term}`;
return function(dispatch) {
axios.get(url)
.then((response) => {
dispatch(getStuffSuccess(response));
})
.catch((err) => {
dispatch(getStuffError(err));
});
};
}
I have also included redux-thunk to the store:
import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux';
import { createStore, applyMiddleware } from 'redux';
import ReduxPromise from "redux-promise";
import Thunk from 'redux-thunk';
import App from './components/app';
import reducers from './reducers';
const createStoreWithMiddleware = applyMiddleware(Thunk, ReduxPromise) (createStore);
ReactDOM.render(
<Provider store={createStoreWithMiddleware(reducers)}>
<App />
</Provider>
, document.querySelector('.container'));
The behaviour hasn't changed from before. The view is still not updating.
NOTE: If I console.log the payload from the Reducer the data is in there. But when I try to do the same in the View nothing happens.
Your action is not synchronus here, you need to use Async Action to deliver the response to reducer, meaning, you have to dispatch the response instead of returning it. Check the given link for more details.
I would try refactoring your /actions/index.js like so:
import axios from 'axios';
export const FETCH_RECIPES = 'fetch_recipes';
export const CREATE_RECIPE = 'create_recipe';
const ROOT_URL = '<url-of-api-endpoint>';
const API_KEY = '<api-key>';
export function fetchRecipes() {
const request = axios.get(`${ROOT_URL}/posts${API_KEY}`);
return {
type: FETCH_RECIPES,
payload: request
};
}
export function createRecipe(values, callback){
const request = axios.post(`${ROOT_URL}/posts${API_KEY}`, values)
.then(() => callback());
return {
type: CREATE_RECIPE,
payload: request
}
}
Can anyone help me figure out what I'm doing wrong? I keep getting actions should be an object use custom middleware error. It works if I try to return like { type: 'SOMETHING' } on the fetchAdmins(), but according to the redux-thunk docs I should be able to return a function that has dispatch as params and that's what I did but maybe I missed something.
store.js
import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import allReducers from './js/reducers/index.js';
const Store = (initialState) =>
createStore(
allReducers,
initialState,
applyMiddleware(thunk)
);
export default Store;
RootAdmin.js
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { bindActionCreators } from 'redux';
import { Route } from 'react-router-dom';
import { fetchAdmins, addAdmin, deleteAdmin } from '../actions/actions.js';
#connect(
state => ({
admins: state.admins
}),
dispatch => bindActionCreators({
fetchAdmins: fetchAdmins,
addAdmin: addAdmin,
deleteAdmin: deleteAdmin
}, dispatch)
)
class RootAdmin extends Component {
// ...codes
componentDidMount() {
this.props.fetchAdmins();
}
// ...codes
}
};
export default RootAdmin;
actions.js
import axios from 'axios';
export function fetchAdmins() {
console.log('fired'); // this gets fired.
return (dispatch) => {
console.log('not fired'); // not fired.
dispatch({ type: 'FETCHING_ADMINS' });
console.log('fetching'); // won't even log
axios({
url: '/api/fetchAdmins'
})
.then(res =>
dispatch({ type: 'FETCHED_ADMINS', payload: res.data })
)
.catch(err =>
dispatch({ type: 'FAILED_FETCH_ADMINS' })
);
};
}
reducer-admins.js
export default function (state = null, action) {
const { payload } = action;
let newState = {...state};
switch (action.type) {
case 'FETCHING_ADMINS':
newState = {...payload};
newState.log += '\nfetching admins';
console.log('fetching admins');
return newState;
break;
}
return state;
}
Thank you very much!
It's not your action creator causing the issue... I believe the issue lies in your mapDispatchToProps
#connect(
state => ({
admins: state.admins
}),
dispatch => bindActionCreators({
fetchAdmins: fetchAdmins,
addAdmin: addAdmin,
deleteAdmin: deleteAdmin
}, dispatch)
)
Note that you're returning an object from the state mapping function, but in your dispatch you're returning the result of bindActionCreators which can be an object or a function...
#connect(
state => ({
admins: state.admins
}),
dispatch => ({
actions: bindActionCreators(Object.assign({}, fetchAdmins, addAdmin, deleteAdmin), dispatch)
})
)
then access your method as this.props.actions.fetchAdmins();