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Problem in converting functional component to class component (ReactJS)

This is my functional component. Works fine
import React from "react";
function RecommendationCard(props) {
const { name, designation, company, message } = props.recommendation;
return (
<div className="col-12 col-md-4">
<div className="card shadow h-100">
<div className="card-body">
<h4 className="card-text">{message}</h4>
<p className="card-text text-secondary mb-0">{name}</p>
<p className="card-text text-secondary">
{designation} at {company}
</p>
</div>
</div>
</div>
);
}
export default RecommendationCard;
The below code is converted state component.Here intead of using props , I used the data from my context.js file like state. It contains all the data like name,company,designation,recommendation. So I'm using it through the consumer . But that is not displaying the properties.
import React, { Component } from 'react';
import { Consumer } from '../context';
class RecommendationCardextends Component {
state = {
name:"",
message:"",
designation:"",
company:"",
}
render() {
return(
<Consumer>
{(value) =>{
const { name, designation, company,message } = this.state;
return (
<div className="col-12 col-md-4">
<div className="card shadow h-100">
<div className="card-body">
<h4 className="card-text">{message}</h4>
<p className="card-text text-secondary mb-0">{name}</p>
<p className="card-text text-secondary">
{designation} at {company}
</p>
</div>
</div>
</div>
);
}}
</Consumer>
);
}
}
export default RecommendationCard;
I request you to please solve this and help me out with this. Thanking you in advance.

<Consumer>
{({ name, designation, company, message }) => (
<div className="col-12 col-md-4">
<div className="card shadow h-100">
<div className="card-body">
<h4 className="card-text">{message}</h4>
<p className="card-text text-secondary mb-0">{name}</p>
<p className="card-text text-secondary">
{designation} at {company}
</p>
</div>
</div>
</div>
)}
</Consumer>
Assuming you don't intend to do anything with it going forward, your local state would be obsolete in the example you provided. All your data is inside value. I personally feel this becomes much easier when using the Hook API useContext.

I made a working example on codesandbox:
https://codesandbox.io/s/exciting-chatelet-7il42?file=/src/App.js
App:
import React from "react";
import "./styles.css";
import RecommendationCard from "./components/RecommendationCard";
import {MyContext} from "./context"
const initialState = {
message: "default message",
company: "default company",
designation: "default designation",
name: "default name"
};
export { MyContext };
export default function App() {
return (
<div className="App">
<MyContext.Provider value={initialState}>
<RecommendationCard />
</MyContext.Provider>
</div>
);
}
RecommendationCard:
import React, { Component } from "react";
import { MyContext } from "../context";
class RecommendationCard extends Component {
static contextType = MyContext;
render() {
return (
<div className="col-12 col-md-4">
<div className="card shadow h-100">
<div className="card-body">
<h4 className="card-text">{this.context.message}</h4>
<p className="card-text text-secondary mb-0">{this.context.name}</p>
<p className="card-text text-secondary">
{this.context.designation} at {this.context.company}
</p>
</div>
</div>
</div>
);
}
}
export default RecommendationCard;
context:
import React from "react";
export const MyContext = React.createContext();

how to show specific post details by clicking using react-router-parameters?

I'm using map to view all posts using axios. And I just want show when I click a specific post to see more information. I'm using react parameters. But it's not working.
Here is my one component
import React, {Component} from 'react';
import Album from './album'
import {Link, BrowserRouter as Router, Route} from 'react-router-dom'
import axios from "axios"
class ViewDataAPI extends Component{
state = {
posts: []
}
componentDidMount(){
axios.get('https://jsonplaceholder.typicode.com/comments')
.then(response => {
this.setState({
posts: response.data
})
})
.catch(error => console.log('error'))
}
render(){
let { posts } = this.state
if(posts.length === 0){
return <h1>Loading...</h1>
}
else{
return(
<Router>
<div className="header">
<div className="container">
<div className="row">
<div className="col-lg-12 col-sm-12 col-xs-12">
<div className="text-center mb-20">
<h1>View Data From API</h1>
<p>using jsx-component, props, state, map in react </p>
</div>
</div>
</div>
<div className="row">
{
posts.map(post =>
{
return (
<Album
key={post.id}
name={post.name}
email = {post.email}
body = {post.body}
view = {post.id}
/>
)
}
)
}
</div>
{/* here is im using params, and to match by clicking specific id to show/view more information */}
<div className="row">
{posts && (
<Route path="/album/:albumId"
render = {({match}) => (
<ViewPosts {...posts.find(pv => pv.id === match.params.albumId)} />
)}
/>
)}
</div>
</div>
</div>
</Router>
)
}
}
}
export default ViewDataAPI;
// This component using for show details
const ViewPosts = ({posts}) =>{
return(
<div className="col-lg-6">
<div className="card border-dark mb-3">
<div className="card-body text-dark">
<div className="album">
<h3>{posts.name}</h3>
<h3>{posts.email}</h3>
<Link to="./">Back To Home</Link>
</div>
</div>
</div>
</div>
);
}
This is album component that has a link
import React, {Component} from 'react'
import {Link} from "react-router-dom"
class Album extends Component{
render(){
return(
<div className="col-lg-6">
<div className="card border-dark mb-3">
<div className="card-body text-dark">
<div className="album">
<h3>{this.props.name}</h3>
<p>{this.props.email}</p>
<p>{this.props.body}</p>
<Link to={`/album/${this.props.view}`}>View</Link>
</div>
</div>
</div>
</div>
);
}
}
export default Album;
https://react-pin.netlify.com/
Please follow the above link to what I'm trying to do. Please first go to one "View Data From API"
My github link https://github.com/sultan0/reactpin

The route param is a string. There is no implicit type conversion
with === Operator. Therefore you have to do it explicitly. Pls. see
Comparison operators for a further explanation.
The spread ... Operator is misplaced here.
The solution is:
<ViewPosts posts={posts.find(pv => pv.id === parseInt(match.params.albumId))} />
Update
You would like to use the Switch component from react router:
Switch is unique in that it renders a route exclusively. In contrast, every Route that matches the location renders inclusively.
Pls refer to react router documentation.
I created a pull request as an example. Hope it helps.

Components not re-rendering on route change - React HashRouter

I've got a problem with react and react-router.
When I click on a link (in my example contact in Footer.js), the url changes, but the desired component Location is not shown. When I refresh the site then, the correct component is displayed.
App.js:
import React, { Component } from 'react';
import { BrowserRouter as Router, HashRouter, Route, Link } from 'react-router-dom';
import 'bootstrap/dist/css/bootstrap.css';
import Footer from './Footer.js';
import Navigation from './Navigation.js';
import Background from './Background.js';
import Home from './Home.js';
import Products from './Products.js';
import Industries from './Industries.js';
import Partner from './Partner.js';
import Location from './Location.js';
import MeetUs from './MeetUs.js';
import ScrollUp from './ScrollUp.js';
import Divider from './Divider.js';
import Country from './Country.js';
import Language from './Language.js';
import Waypoint from 'react-waypoint';
import $ from "jquery";
class App extends Component {
constructor(props) {
super(props);
this.state = {
currentLanguage: 'en',
currentBU: '',
currentIndustry: '',
showMainProductGroups: false,
currentCountry: 'group',
countryObject: Country['group'],
contacts: [],
mainProductGroups: [],
};
}
handleCountryChange() {
//...
}
handleLanguageChange() {
//...
}
handleBUChange() {
//...
}
render() {
const routes = [
{
path: '/',
exact: true,
components: () =>
<div>
<Home key="home" currentLanguage={this.state.currentLanguage} />
</div>,
},
{
path: '/contact',
exact: true,
components: () => <Location key="locations" currentLanguage={this.state.currentLanguage} country={this.state.countryObject} contacts= {this.state.contacts} onCountryChange={this.handleCountryChange.bind(this)} />
},
]
return (
<HashRouter>
<div>
<Background />
<div id="wrap">
<div id="main" className="container clear-top marginBottom50px">
<div id="content">
<Navigation key="navBar" currentLanguage={this.state.currentLanguage} onLanguageChange={this.handleLanguageChange.bind(this)} onBUChange={this.handleBUChange.bind(this)} onCountryChange={this.handleCountryChange.bind(this)} />
{
routes.map((route, index) => (
<Route key={index} path={route.path} exact={route.exact} component={route.components} />
))
}
</div>
</div>
</div>
<Footer key="footer" currentLanguage={this.state.currentLanguage} />
<ScrollUp key="scrollUp" />
</div>
</HashRouter>
);
}
}
export default App;
Home.js:
import React, { Component } from 'react';
import $ from "jquery";
import { Link } from 'react-router-dom';
import {withRouter} from 'react-router';
import Language from './Language.js';
import locations from './locations.jpg';
import locationLegend from './locationLegend.jpg';
require('bootstrap')
class Home extends Component {
constructor(props) {
super(props);
this.state = {
};
}
render() {
return (
<div className="container marginTop50px marginBottom50px area">
<div className="row">
<div className="col-12 text-center animDelay2 fadeInDown animated">
<h1>International Distribution of Specialty Chemicals</h1>
</div>
</div>
<div className="row marginTop25px">
<div className="col-12 text-center animDelay2 fadeInUp animated">
{Language[this.props.currentLanguage].homeStartText}
</div>
</div>
<div className="row marginTop25px">
<div className="col-12 text-center">
<img src={locations} className="img-fluid" alt="Locations" />
</div>
</div>
<div className="row marginTop25px">
<div className="col-12 text-center">
<img src={locationLegend} className="img-fluid" alt="Locations" />
</div>
</div>
</div>
);
}
}
export default withRouter(Home);
Location.js:
import React, { Component } from 'react';
import $ from "jquery";
import { Link } from 'react-router-dom';
import Language from './Language.js';
import Country from './Country.js';
import ContactPerson from './ContactPerson.js';
import locations from './locations.png';
import phone from './phoneBlack.svg';
import fax from './faxBlack.svg';
import email from './emailBlack.svg';
import {withRouter} from 'react-router';
require('bootstrap');
class Location extends Component {
constructor(props) {
super(props);
this.state = {
};
}
componentDidUpdate(prevProps, prevState, snapshot) {
console.log('Country change:' + this.props.country.key);
$('#selectCountry').val(this.props.country.key); //name['en']
}
onCountryChange() {
let countryName = this.refs.country.value;
this.props.onCountryChange(countryName);
}
render() {
return (
<div className="container marginTop50px marginBottom50px area" id="locations">
<div className="row">
<div className="col-12 text-center">
<h2>{Language[this.props.currentLanguage].locations}</h2>
</div>
</div>
<div className="row marginTop25px">
<div className="col-12 text-center">
<div className="form-group">
<select id="selectCountry" className="form-control" ref="country" onChange={this.onCountryChange.bind(this)}>
<option defaultValue>{Language[this.props.currentLanguage].selectLocation.toUpperCase()}</option>
{
Object.keys(Country).map((countryKey) => {
const country = Country[countryKey];
return (
<option value={countryKey} key={"loc" + countryKey}>{country.name[this.props.currentLanguage].toUpperCase()}</option>
);
})
}
</select>
</div>
</div>
</div>
<div className="row marginTop25px">
<div className="col-12 text-center">
{this.props.country.name[this.props.currentLanguage].toUpperCase()}
<br />
<address>
<span dangerouslySetInnerHTML={{__html: this.props.country.address}}></span>
<br />
<br />
<img src={phone} alt="Anrufen" className="phoneMain"></img><span> </span>
<a href={this.props.country.phoneHTML}>{this.props.country.phone}</a>
<br />
<img src={fax} alt="Fax" className="phoneMain"></img><span> </span>
<a href={this.props.country.faxHTML}>{this.props.country.fax}</a>
<br />
<img src={email} alt="Email" className="emailMain"></img><span> </span>
<a href={"mailto://" + this.props.country.email}>{this.props.country.email}</a>
</address>
</div>
</div>
<div className="row marginTop25px">
<div className="col-12 text-center">
{Language[this.props.currentLanguage].vatRegistrationNumber + ": " + this.props.country.vatNo}
<br />
{Language[this.props.currentLanguage].registrationOffice + ": "}
<span dangerouslySetInnerHTML={{__html: this.props.country.registrationOffice}}></span>
</div>
</div>
<div className="row marginTop50px">
<div className="col-12 text-center">
<h3>{Language[this.props.currentLanguage].contact}</h3>
</div>
</div>
<div className="row">
{
this.props.contacts.map((contact) => {
return (
<div className="col-12 col-sm-12 col-md-12 col-lg-6 text-center">
<ContactPerson contact={contact} key={"contact" + contact.id} />
</div>
);
})
}
</div>
</div>
);
}
}
export default withRouter(Location);
Footer.js:
import React, { Component } from 'react';
import $ from "jquery";
import { Link } from 'react-router-dom';
import {withRouter} from 'react-router';
import Language from './Language.js';
import phone from './phoneWhite.svg';
import fax from './faxWhite.svg';
require('bootstrap');
class Footer extends Component {
constructor(props) {
super(props);
this.state = {
};
}
render() {
return (
<footer className="footer">
<div className="container-fluid borderTop1px footerLayout">
<div className="row">
<div className="col-3">
<address>
<small>
Some text
</small>
</address>
</div>
<div className="col-6 text-center">
<div className="row">
<div className="col-12 col-sm-12 col-md-12 col-lg-3 text-center">
<small>{Language[this.props.currentLanguage].download}</small>
</div>
<div className="col-12 col-sm-12 col-md-12 col-lg-3 text-center">
<Link to="/imprint" className="nav-link footerLink"><small>{Language[this.props.currentLanguage].imprint}</small></Link>
</div>
<div className="col-12 col-sm-12 col-md-12 col-lg-3 text-center">
<Link to="/contact" className="nav-link footerLink"><small>{Language[this.props.currentLanguage].contact}</small></Link>
</div>
<div className="col-12 col-sm-12 col-md-12 col-lg-3 text-center">
<Link to="/termsAndConditions" className="nav-link footerLink"><small>{Language[this.props.currentLanguage].termsAndConditions}</small></Link>
</div>
</div>
</div>
<div className="col-3">
<ul className="list-inline">
<li>
<img src={phone} alt="Anrufen" className="phone"></img> <small><a className="footerLink" href="tel:+49">+49</a></small>
</li>
<li>
<img src={fax} alt="Fax" className="phone"></img> <small><a className="footerLink" href="tel:+49">+49</a></small>
</li>
</ul>
</div>
</div>
</div>
</footer>
);
}
}
export default withRouter(Footer);
What I'm doing wrong? Why it is not working, when I click on a link?

Got it working now.
I needed to change <HashRouter> to <Router>. Then it works fine.
UPDATE:
This solution solves the problem, but then there is a different problem: When I have navigated and refresh the page, then an error (404) is thrown, because there is of course no such a page on the server.
I need to get the HashRouter work.

When you declare your routes in App.js, you should pass the props to the component:
components: props => <Location {...props} <insert other props> />
You should stick to the <Router> solution as having unnecessary hash in the url is ugly.
When I have navigated and refresh the page, then an error (404) is thrown, because there is of course no such a page on the server.
To resolve this, you need to set up a redirect to redirect all requests to the base url for the React app to handle (the url displayed will be preserved).
On Netlify, you can create a _redirects file in your public folder with the content:
/* /index.html 200
On AWS S3, the redirect rules can be set in S3 or CloudFront, see the answers here.
For Google Cloud bucket, see this.
For Github pages, see this.

In your Route component you use component prop to pass the Location component (instead of render or children props available on Route) the router uses React.createElement to create a new React element from the given component. That means if you provide an inline function to the component prop, you would create a new component every render. This results in the existing component unmounting and the new component mounting instead of just updating the existing component. When using an inline function for inline rendering, use the render or the children prop.However in your case it seems you are using it for no reason so you should just pass the component and not an inline function that returns it like so :
const routes = [
{
path: '/',
exact: true,
components: <Home key="home" currentLanguage={this.state.currentLanguage}/>
},
{
path: '/contact',
exact: true,
components: <Location key="locations" currentLanguage={this.state.currentLanguage} country={this.state.countryObject} contacts= {this.state.contacts} onCountryChange={this.handleCountryChange.bind(this)} />
},
]

Make your routes use Component as below
import {IndexRoute, Route} from 'react-router';
<Route component={App}>
<Route path='/locations' component={LocationComponent}/>
</Route>
This is what I am doing in my current project without using HashRouter.
Currently, When you do
<Route key={index} path={route.path} exact={route.exact} component={route.components} />
I don't think {route.components} treats it as a component.

Could be a problem with withRouter().
Have you seen this?
https://github.com/ReactTraining/react-router/issues/5037

Why does the twitter widget not re-render reactjs

I am using the twitter embedded timeline on my application to show the twitter feed of a companies twitter account.
When I get a result from an API, the state changes to the correct values, but the twitter widget does not appear to change
TwitterCard.js
import React from "react";
export class TwitterCard extends React.Component{
render() {
return (
<a className="twitter-timeline" href={this.props.href} data-height="100%">Tweets by {this.props.ticker}</a>
)
}
}
I have attached screenshots of the react plugin output for proof of state change.
The parent class is rather large, so I have posted the render method:
render() {
return (
<div>
<NavBar/>
<div className="container-fluid">
<div className="row">
<NavBarSide clickHandler={(url) => this.handleNavClick(url)}/>
<Dashboard
errorChart={this.state.errorChart}
twitter={this.state.twitter}
status={this.state.status}
/>
</div>
</div>
</div>
)
}
The parent passes these values to the Dashboard:
import React from "react";
import { Switch, Route } from 'react-router-dom';
import { Chart } from "./Chart";
import { TwitterCard } from "./TwitterCard";
export class Dashboard extends React.Component {
render() {
return (
<div className="col-md-9 ml-sm-auto col-lg-10 pt-2 px-3">
<div className="row">
<div className="col-lg-8">
<div className="row">
<div className="col-lg-6">
<div className="card border-0">
<div className="card-body">
<Chart chart={this.props.errorChart}/>
</div>
</div>
</div>
</div>
</div>
<div className="col-lg-4">
<TwitterCard href={this.props.twitter} ticker={this.props.ticker}/>
</div>
</div>
</div>
)
}
}

You can force an update to the twitter component when the ticket changes by keying it with the ticker where you render it in your dashboard component:
<TwitterCard
key={this.props.ticker}
href={this.props.twitter}
ticker={this.props.ticker}
/>

Cannot read props type of 'undefined'

Im trying to pass simple properties from my child component to the parent component . I can't for the life of me understand why I'm getting this error. My understanding of react is that you can declare props (i.e. this.props.text) in any function or class and then pass it to the parent.
Tickerbox.js (child)
import React from 'react';
import './App.css';
function Tickerbox(props) {
return (
<div className="container">
<div className="row">
<div className="col-sm-6">
<h1></h1>;
</div>
<div className="col-sm-6">
<h1>{this.props.text}</h1>;
</div>
</div>
</div>
);
}
export default Tickerbox;
App.js (parent)
import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';
import Tickerbox from './TickerBox';
class App extends Component {
constructor(props) {
super(props);
this.state = {
day: 'monday',
month: 'january',
year: '1st',
};
}
render() {
return (
<div className="App">
<link rel="stylesheet"
href="https://maxcdn.bootstrapcdn.com/bootstrap/latest/css/bootstrap.min.css"/>
<div className="App-header">
<img src={logo} className="App-logo" alt="logo" />
<h2>Hi</h2>
</div>
<div className="container">
<div className="row">
<div className="col-sm-2 col-sm-push-3">day</div>
<div className="col-sm-2 col-sm-push-3">month</div>
<div className="col-sm-2 col-sm-push-3">year</div>
<Tickerbox text="test"></Tickerbox>
</div>
</div>
</div>
);
}
}
export default App;
Index.js (entry point)
import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import registerServiceWorker from './registerServiceWorker';
ReactDOM.render(<App />, document.getElementById('root'));
registerServiceWorker();

Tickerbox it's a stateless component.
Stateless components are declared as function
you are trying to access to this.props.text but you already have the props in the arguments props
Instead of use this use the props passed that are the actual props for that component
Tickerbox.js
import React from 'react';
import './App.css';
function Tickerbox(props) {
return (
<div className="container">
<div className="row">
<div className="col-sm-6">
<h1></h1>;
</div>
<div className="col-sm-6">
<h1>{props.text}</h1>;
</div>
</div>
</div>
);
}
export default Tickerbox;

Issue is we cannot access this.props.text in functional components. It should either be props.text or make it a class based component.
<h1>{props.text}</h1>;