Develop Reference

How to set loader for a promise.all action in React Redux?

So when I check Redux dev-tools i see that I've received my data and they are a part of the state, but when I try to use conditional rendering it wont render the page and gives error TypeError: Cannot read property 'Global Quote' of undefined !
If I just use this.props.data.TSLA it works fine and the page renders...
When I use this.props.data.TSLA["Global Quote"]["01. symbol"] page won't render! (the keys are strings in the JSON so I need to use square brackets).
I am also using Redux-Thunk !
import { connect } from 'react-redux';
import { bindActionCreators } from 'redux';
import { START_FETCH_DATA } from './redux/dataReducer';
class Fetcher extends Component {
componentDidMount() {
this.props.START_FETCH_DATA()
}
render() {
const { data, dataLoading } = this.props;
return (
<li className="tesla-container">
{ this.props.dataLoading ?
(<div className="ticker"> Loading! </div>)
:
(<div className="ticker">{
this.props.data.TSLA["Global Quote"]["01. symbol"] }</div>) }
</li>
)
}
const mapStateToProps = (state) => {
return {
data: state.data,
dataLoading: state.dataLoading
}
}
const mapDispatchToProps = (dispatch) => {
return {
START_FETCH_DATA: bindActionCreators(START_FETCH_DATA, dispatch)
}
}
export default connect(mapStateToProps, mapDispatchToProps)(Fetcher)
and here is the reducer + actions...
export const dataReducer = (state = {dataLoading: true}, action) => {
switch(action.type) {
case "START_FETCH_DATA":
return {...state, dataLoading: true}
case "FINISH_FETCH_DATA":
return {...state, dataLoading: false, data: action.payload}
default:
return state;
}};
export const START_FETCH_DATA = () => {
return (dispatch) => {
Promise.all(
[
fetch(`https://www.alphavantage.co/query?function=GLOBAL_QUOTE&symbol=TSLA&apikey=LOL`).then(data => data.json()),
fetch(`https://www.alphavantage.co/query?function=GLOBAL_QUOTE&symbol=AMZN&apikey=LOL`).then(data => data.json())
]
)
.then(([TSLA, AMZN]) => {
dispatch({ type: "FINISH_FETCH_DATA", payload: {TSLA, AMZN} })
})
}};
DEVTOOLS SCREENSHOT
https://imgur.com/a/2Tcrdpe

For starters, you should use the data provided by redux in render():
import { connect } from 'react-redux';
import { bindActionCreators } from 'redux';
import { START_FETCH_DATA, dataReducer } from './redux/dataReducer';
class Fetcher extends Component {
componentDidMount() {
this.props.START_FETCH_DATA()
}
render() {
return (
<li className="tesla-container">
{ this.props.dataLoading ?
(<div className="ticker"> Loading! </div>)
:
(<div className="ticker">{
this.props.data.TSLA["Global Quote"]["01. symbol"] }</div>) }
</li>
)
}
const mapStateToProps = (state) => {
return {
data: state.data,
dataLoading: state.dataLoading
}
}
const mapDispatchToProps = (dispatch) => {
return {
START_FETCH_DATA: bindActionCreators(START_FETCH_DATA, dispatch)
}
}
export default connect(mapStateToProps, mapDispatchToProps)(Fetcher)

I fixed my issue.
Fixed code below:
`const mapStateToProps = (state) => {
return {
dataLoading: state.dataReducer.dataLoading,
data: state.dataReducer.data
}
}`
instead of
`const mapStateToProps = (state) => {
return {
dataLoading: state.dataLoading,
data: state.data
}
}`

Updating redux state onClick

I have a component that displays data from the state. I'm using redux for state. I want to be able to click a button and filter the state. But I'm stuck on dispatching the action from the button.
Right now I have a button that is supposed to dispatch the action but it's not being called. I'm not sure if the mapsToDispatchProps is wrong or it's something else.
Here is the actions
import { GET_POLLS, SHOW_APPROVAL } from './types';
const URL = 'https://projects.fivethirtyeight.com/polls/polls.json';
export const getPolls = () => dispatch => {
return fetch(URL)
.then(res => res.json())
.then(polls => {
dispatch({ type: GET_POLLS, payload: polls })
})
}
export const getApproval = () => ({ type: SHOW_APPROVAL })
reducer
import {
GET_POLLS,
SHOW_APPROVAL
} from '../actions/types';
const pollReducer = (state = [], { type, payload }) => {
switch (type) {
case GET_POLLS:
return payload
case SHOW_APPROVAL:
return (payload.type === "trump-approval")
default:
return state
}
}
export default pollReducer;
types
export const GET_POLLS = 'GET_POLLS';
export const POLLS_LOADING = 'POLLS_LOADING';
export const SHOW_ALL = 'SHOW_ALL';
export const SHOW_APPROVAL = 'SHOW_APPROVAL';
list that displays data
import React, { Component } from 'react'
import { PollCard } from '../Components/PollCard'
// import FilterLink from './FilterLink'
import * as moment from 'moment';
import { connect } from 'react-redux'
import { getPolls, getApproval } from '../actions/index';
class PollList extends Component {
componentDidMount() {
this.props.getPolls();
}
render() {
console.log("rendering list")
const { polls } = this.props
const range = 30
var dateRange = moment().subtract(range, 'days').calendar();
var filteredPolls = polls.filter(e => Date.parse(e.endDate) >= Date.parse(dateRange)).reverse()
return (
<React.Fragment>
<button onClick={getApproval}>
Get Approval
</button>
{console.log("get approval", getApproval)}
{
filteredPolls && filteredPolls.map((poll) => (
<div key={poll.id}>
<PollCard poll={poll} />
{/* {(poll.type)} */}
</div>
))
}
</React.Fragment>
)
}
}
const mapStateToProps = state => ({
polls: state.polls
});
const mapDispatchToProps = {
getApproval
};
export default connect(
mapStateToProps,
mapDispatchToProps,
{ getPolls, getApproval }
)(PollList);
// export default PollList;

Your mapDispatchToProps() appears to be configured incorrectly. You need to define a function that returns an object, defining a key-value pair for each action you want to make available as a prop in your component.
const mapDispatchToProps = (dispatch) => {
return {
getApproval: () => {
dispatch(getApproval())
},
getPolls: () => {
dispatch(getPolls())
}
}
}
export default connect(
mapStateToProps,
mapDispatchToProp)(PollList);
Now getPolls is available as prop and you can use it in componentDidMount()
componentDidMount() {
this.props.getPolls();
}
You should also create an onClick handler for your getApproval action
handleClick = () => {
this.props.getApproval()
}
And then connect it to your onClick event-listener
<React.Fragment>
<button onClick={this.handleClick}>
Get Approval
</button>
console.log("get approval", getApproval)}
{
filteredPolls && filteredPolls.map((poll) => (
<div key={poll.id}>
<PollCard poll={poll} />
{/* {(poll.type)} */}
</div>
))
}
</React.Fragment>
Action File
export const getPolls = () => dispatch => {
fetch(URL)
.then(res => res.json())
.then(polls => {
dispatch({ type: GET_POLLS, payload: polls })
})
.catch(errors => {
dispatch({ type: "GET_ERRORS", payload: errors.response.data })
})
}
Reducer
import {
GET_POLLS,
SHOW_APPROVAL
} from '../actions/types';
const pollReducer = (state = [], { type, payload }) => {
switch (type) {
case GET_POLLS:
return payload
case SHOW_APPROVAL:
return state.filter((poll) => {
return poll.type === "trump-approval"
})
case "GET_ERRORS":
return payload
default:
return state
}
}
export default pollReducer;

You are not calling the action function.
// Either destructure it
const { polls, getApproval } = this.props;
<button onClick={getApproval}>
Get Approval
</button>
// Or use this.props.function
<button onClick={this.props.getApproval}>
Get Approval
</button>
// You don't need this
const mapDispatchToProps = {
getApproval
};
// You don't need this
const mapStateToProps = state => {
return {polls: state.polls};
};
export default connect(
mapStateToProps,
// Doing this is easier, cleaner & faster
{ getPolls, getApproval }
)(PollList);
Here you are doing it correctly;
componentDidMount() {
this.props.getPolls();
}

Action doesn't update the store

|I have the following component based on this:
**WarningModal.js**
import React from 'react';
import ReactDOM from 'react-dom';
import {connect, Provider} from 'react-redux';
import PropTypes from 'prop-types';
import {Alert, No} from './pure/Icons/Icons';
import Button from './pure/Button/Button';
import Modal from './pure/Modal/Modal';
import {setWarning} from '../actions/app/appActions';
import configureStore from '../store/configureStore';
const store = configureStore();
export const WarningModal = (props) => {
const {message, withCleanup} = props;
const [
title,
text,
leave,
cancel
] = message.split('|');
const handleOnClick = () => {
props.setWarning(false);
withCleanup(true);
}
return(
<Modal>
<header>{title}</header>
<p>{text}</p>
<Alert />
<div className="modal__buttons-wrapper modal__buttons-wrapper--center">
<button
onClick={() => withCleanup(false)}
className="button modal__close-button button--icon button--icon-only button--text-link"
>
<No />
</button>
<Button id="leave-warning-button" className="button--transparent-bg" onClick={() => handleOnClick()}>{leave}</Button>
<Button id="cancel-warning-button" onClick={() => withCleanup(false)}>{cancel}</Button>
</div>
</Modal>
);
}
WarningModal.propTypes = {
withCleanup: PropTypes.func.isRequired,
message: PropTypes.string.isRequired,
setWarning: PropTypes.func.isRequired
};
const mapStateToProps = state => {
console.log(state)
return {
isWarning: state.app.isWarning
}
};
const WarningModalContainer = connect(mapStateToProps, {
setWarning
})(WarningModal);
export default (message, callback) => {
const modal = document.createElement('div');
document.body.appendChild(modal);
const withCleanup = (answer) => {
ReactDOM.unmountComponentAtNode(modal);
document.body.removeChild(modal);
callback(answer);
};
ReactDOM.render(
<Provider store={store}>
<WarningModalContainer
message={message}
withCleanup={withCleanup}
/>
</Provider>,
modal
);
};
the issue I have is that 'setWarning' doesn't update the state, it does get called as I have a debugger inside the action and the reducer but the actual property doesn't not change to 'false' when:
props.setWarning(false);
gets called.
I use the following to trigger the custom modal:
const togglePromptCondition =
location.hash === '#access-templates' || location.hash === '#security-groups'
? promptCondition
: isFormDirty || isWarning;
<Prompt message={promptMessage} when={togglePromptCondition} />
To test this even further I have added 2 buttons in the application to toggle 'isWarning' (the state property I am talking about) and it works as expected.
I think that although WarningModal is connected in actual fact it isn't.
REDUCER
...
case SET_WARNING:
console.log('reducer called: ', action)
return {
...state,
isWarning: action.payload
};
...
ACTION
...
export const setWarning = status => {
console.log('action called')
return {
type: SET_WARNING,
payload: status
}
};
...
UPDATE
After having to incorporates the following:
const mapStateToProps = state => {
return {
isWarning: state.app.isWarning
}
};
const mapDispatchToProps = dispatch => {
return {
setWarning: (status) => dispatch({ type: 'SET_WARNING', payload: status })
}
};
I am now getting:
Maybe this could help?

You have to dispatch the actions in the action creator and the type of the action to dispatch should be always string.
Try this
const mapStateToProps = state => {
console.log(state)
return {
isWarning: state.app.isWarning
}
};
const mapDispatchToProps = dispatch => {
console.log(dispatch)
return {
setWarning: (status) => dispatch({ type: 'SET_WARNING', payload: status })
}
};
const WarningModalContainer = connect(mapStateToProps, mapDispatchToProps)(WarningModal);
REDUCER
...
case 'SET_WARNING':
console.log('reducer called: ', action)
return {
...state,
isWarning: action.payload
};
...

React-Reudx: Actions must be plain objects. Use custom middleware for async actions

I made a counter example with react-redux, but there seems to be errors.
error message is 'Actions must be plain objects. Use custom middleware for async actions.'
And error line is
const mapDispatchToProps = dispatch => {
15 | return {
> 16 | handleIncrease: () => dispatch(actions.increase()),
17 | handleDecrease: () => dispatch(actions.decrease())
18 | };
19 | };
---------------=--------------
First, actions/actionTypes.js
export const INCREASE = "INCREASE";
export const DECREASE = "DECREASE";
actions/index.js
import * as types from "./actionTypes";
export const increase = number => {
type: types.INCREASE, number;
};
export const decrease = number => {
type: types.DECREASE, number;
};
reducers/index.js
import { combineReducers } from "redux";
import number from "./number";
const reducers = combineReducers({
number
});
export default reducers;
reducers/number.js
import * as types from "../actions/actionTypes";
const number = (state = 0, action) => {
switch (action.type) {
case types.INCREASE:
return { ...state, number: action.number + 1 };
case types.DECREASE:
return { ...state, number: action.number - 1 };
default:
return state;
}
};
export default number;
components/Counter.js
import React, { Component } from "react";
export default class Counter extends Component {
render() {
const { number, onIncrease, onDecrease } = this.props;
return (
<div>
<h1>Counter</h1>
<div>Value: {number}</div>
<button onClick={onIncrease}>+</button>
<button onClick={onDecrease}>-</button>
</div>
);
}
}
Last, App.js
import React, { Component } from "react";
import "./App.css";
import Counter from "./components/Counter";
import { connect } from "react-redux";
import * as actions from "./actions";
const mapStateToProps = state => {
return {
number: state.number
};
};
const mapDispatchToProps = dispatch => {
return {
handleIncrease: () => dispatch(actions.increase()),
handleDecrease: () => dispatch(actions.decrease())
};
};
class App extends Component {
render() {
return (
<div className="App">
<Counter
number={this.props.number}
onIncrease={this.props.handleIncrease}
onDecrease={this.props.handleDecrease}
/>
</div>
);
}
}
export default connect(mapStateToProps, mapDispatchToProps)(App);
Which part is wrong?
I am curious too.
Thanks.
I fix this error, but next occurs new error
error message is
Uncaught Error: Objects are not valid as a React child (found: object with keys {number}). If you meant to render a collection of children, use an array instead.
in div (at Counter.js:9)
in div (at Counter.js:7)
in Counter (at App.js:25)
in div (at App.js:24)
in App (created by Connect(App))
in Connect(App) (at index.js:16)
in Provider (at index.js:15)
at invariant (invariant.js:42)
at throwOnInvalidObjectType (react-dom.development.js:7362)
at updateSlot (react-dom.development.js:7631)
at reconcileChildrenArray (react-dom.development.js:7762)
at reconcileChildFibers (react-dom.development.js:8121)
at reconcileChildrenAtExpirationTime (react-dom.development.js:8248)
at reconcileChildren (react-dom.development.js:8231)
at updateHostComponent (react-dom.development.js:8539)
at beginWork (react-dom.development.js:8986)
at performUnitOfWork (react-dom.development.js:11814)
at workLoop (react-dom.development.js:11843)
at HTMLUnknownElement.callCallback (react-dom.development.js:100)
at Object.invokeGuardedCallbackDev (react-dom.development.js:138)
at invokeGuardedCallback (react-dom.development.js:187)
at replayUnitOfWork (react-dom.development.js:11318)
at renderRoot (react-dom.development.js:11885)
at performWorkOnRoot (react-dom.development.js:12449)
at performWork (react-dom.development.js:12370)
at performSyncWork (react-dom.development.js:12347)
at interactiveUpdates (react-dom.development.js:12597)
at interactiveUpdates (react-dom.development.js:1958)
at dispatchInteractiveEvent (react-dom.development.js:4259)

You do not return anything here:
export const increase = number => {
type: types.INCREASE, number;
};
export const decrease = number => {
type: types.DECREASE, number;
};
Fix it by actually returning an object:
export const increase = number => {
return {
type: types.INCREASE, number
}
};
export const decrease = number => {
return {
type: types.DECREASE, number
}
};
or more concise:
export const increase = number => ({
type: types.INCREASE, number;
});
export const decrease = number => ({
type: types.DECREASE, number;
});
EDIT:
You also need to fix the reducer:
const number = (state = 0, action) => {
switch (action.type) {
case types.INCREASE:
return state + 1;
case types.DECREASE:
return state - 1;
default:
return state;
}
};
a state is a sole Number so you don't need to copy any values. You were returning an object from your reducer that's why react couldn't render it.

I never see you use bindActionCreators.
example
const {createStore, bindActionCreators} = Redux;
const {Component} = React;
const { connect, Provider } = ReactRedux;
const TestClicker = (props) => {
return(
<button onClick={props.onClick}>Click Me</button>
)
}
class App extends React.Component {
constructor(){
super();
}
render(){
return(
<div>
<h1>Hello</h1>
<p>{this.props.work}</p>
<TestClicker onClick={this.props.testAction}/>
<TestClicker onClick={this.props.testAction2}/>
<TestClicker onClick={this.props.testAction3}/>
</div>
);
}
}
function mapStateToProps(state){
return {
work: state.working
}
}
function mapDispatchToProps(dispatch){
return bindActionCreators({
testAction: changeAc1,
testAction2: changeAc2,
testAction3: changeAc3
}, dispatch);
}
App = connect(mapStateToProps, mapDispatchToProps)(App);
const changeAc1 = (action) => {
console.log("I've been clicked");
return {
type: "GO"
}
}
const changeAc2 = (action) => {
console.log("I've been clicked");
return {
type: "YES"
}
}
const changeAc3 = (action) => {
console.log("I've been clicked");
return {
type: "GLOW"
}
}
const initialState = { working: "no" };
const reducer = (state, action) => {
switch(action.type){
case "GO":
return Object.assign({}, state, { working: "yes" });
case "YES":
return Object.assign({}, state, { working: "HELL YESSS!!!" });
case "GLOW":
return Object.assign({}, state, { working: "This is the SHIIIIIIIIZZZZZ" });
default:
return state;
}
}
const store = createStore(reducer, initialState);
ReactDOM.render(
<Provider store={store}>
<App />
</Provider>,
document.getElementById('root')
);
Link to codepen https://codepen.io/ar-traunworks/pen/MrNYqX
You are either mutating the state (try to store number in variable, return the whole state ...state, then the number property mutate that example {...state, number: (the variable)}) or you need to check how you have binded your actions.

mapDispatchToProps dispatch action not working to update State

In my index.js the addCoin action is working.
import { addCoin } from './reducer/portfolio/actions'
const element = document.getElementById('coinhover');
const store = createStore(reducer, compose(
applyMiddleware(thunk),
window.__REDUX_DEVTOOLS_EXTENSION__ && window.__REDUX_DEVTOOLS_EXTENSION__()
));
store.dispatch(addCoin('bitcoin'));
When store.dispatch is called I can see the updated state here.
However I do not want to call dispatch actions from my index.js, but from within my components.
My SearchCoin component:
import React from 'react'
import { connect } from 'react-redux'
import * as R from 'ramda'
import * as api from '../../services/api'
import { addToPortfolio, findCoins } from '../../services/coinFactory'
import { addCoin } from '../../reducer/portfolio/actions'
const mapDispatchToProps = (dispatch) => ({
selectCoin(coin) {
return () => {
dispatch(addCoin(coin))
}
}
});
class SearchCoin extends React.Component {
constructor(props) {
super(props)
this.state = {
searched: []
};
// console.log('props', props);
this.close = this.close.bind(this);
}
componentDidMount() {
this.coinInput.focus();
this.handleChange = this.handleChange.bind(this);
this.clickCoin = this.clickCoin.bind(this);
}
handleChange() {
const text = document.getElementById('coin-search').value;
const search = (text) => this.setState({ searched: findCoins(text) });
const clearSearch = () => this.setState({ searched: [] });
text.length > 1 ? search(text) : clearSearch();
}
clickCoin(coin) {
console.log('clickCoin', coin);
// api.getCoin(coin.id).then((res) => {
// const apiCoin = R.head(res.data);
// addToPortfolio(apiCoin);
// });
this.props.selectCoin(coin);
this.props.closeSearch();
}
close() {
this.props.closeSearch();
}
render() {
const searched = this.state.searched.map((coin) => {
return (
<li key={ coin.id } onClick={ ()=> this.clickCoin(coin) }>
<div className="coin-logo">
<img src={ coin.logo }/>
</div>
<span>{ coin.name }</span>
</li>
);
});
return (
<div id="search-coin-component">
<input type="text"
id="coin-search"
className="coin-search-input fl"
placeholder="Search"
onChange={ ()=> this.handleChange() }
ref={ (input) => { this.coinInput = input; } } />
<div className="icon-cancel-outline fl" onClick={ this.close }></div>
<div className="coin-select">
<ul>
{ searched }
</ul>
</div>
</div>
)
}
}
export default connect(null, mapDispatchToProps)(SearchCoin)
This is the onClick:
<li key={ coin.id } onClick={ ()=> this.clickCoin(coin) }>
At the bottom of the file I am using connect to add mapDispatchToProps
export default connect(null, mapDispatchToProps)(SearchCoin)
Here is the class method clickCoin which calls this.props.selectCoin
clickCoin(coin) {
console.log('clickCoin', coin);
this.props.selectCoin(coin);
this.props.closeSearch();
}
Finally selectCoin
import { addCoin } from '../../reducer/portfolio/actions'
const mapDispatchToProps = (dispatch) => ({
selectCoin(coin) {
return () => {
dispatch(addCoin(coin))
}
}
});
However when I click the button it seems like the dispatch is not fired as nothing happens to the redux state.
import * as R from 'ramda'
import * as api from '../../services/api'
import { addToPortfolio } from '../../services/coinFactory'
export const ADD_COIN = 'ADD_COIN'
export function addCoin(coin) {
console.log('addCoin', coin);
return dispatch =>
api.getCoin(coin)
.then((res) => addToPortfolio(R.head(res.data)))
.then((portfolio) => dispatch(add(portfolio)));
}
// action creator
export function add(portfolio) {
return {
type: ADD_COIN,
portfolio
}
}
The reducer
import { ADD_COIN } from './actions'
const initialState = [];
export default (state = initialState, action) => {
switch(action.type) {
case ADD_COIN:
return action.portfolio;
default:
return state;
}
}
the reducer/index.js
import { combineReducers } from 'redux'
import portfolio from './portfolio'
export default combineReducers({
portfolio
});

Apart from azium answer, you can use actions like this. It saves you some writing,
export default connect(null, {addCoin})(SearchCoin)
and you can use it like this,
clickCoin(coin) {
console.log('clickCoin', coin);
this.props.addCoin(coin);
this.props.closeSearch();
}

The problem is that you are wrapping your function with an extra function.
Change:
const mapDispatchToProps = (dispatch) => ({
selectCoin(coin) {
return () => { <--- returning extra function
dispatch(addCoin(coin))
}
}
})
to:
const mapDispatchToProps = (dispatch) => ({
selectCoin(coin) { dispatch(addCoin(coin)) }
})