I use the class component in my Cart.js file but it got the error as "render is not a function". I also try changing it into a function component but it's not working either, please help me to find a way to fix it! Thank you so much!
My sandbox link: https://codesandbox.io/s/why-cant-i-fetch-data-from-a-passed-value-forked-buz0u?file=/src/App.js
Cart component has error, because you're using Consumer from ProductContext in a incorrect way. Change it this code will solve the problem:
import React from "react";
const ProductContext = React.createContext();
export default class Cart extends React.Component {
render() {
return (
<div>
<ProductContext.Consumer>
{(value) => {
return <div>hello</div>
}}
</ProductContext.Consumer>
</div>
);
}
}
Please change your cart component
import React from "react";
const ProductContext = React.createContext();
export default class Cart extends React.Component {
render() {
return (
<div>
<ProductContext.Provider value={null}>
hello
</ProductContext.Provider>
</div>
);
}
}
Related
I have a component that I want to show in another site.
components/Hello.js
import React from 'react';
export default class Hello extends React.Component {
render() {
return (
<div><p>Hello</p></div>
)
};
};
Now I want to import it into my site named "Profile.js".
pages/Profile.js
import React from 'react';
import Hello from '../components/Hello';
export default function Profile() {
return(
<div>
{/* Say hello*/}
{Hello}
</div>
);
}
What am I doing wrong? Why wont it say hello on my "Profile.js" page?
React syntax for rendering components is as follow :
export default function Profile() {
return(
<div>
{/* Say hello*/}
<Hello/>
</div>
);
}
i have a question about the range of the props. I would in my App.js just call the component with 2 props (just below) and use those props in my other file "PrimaryButton.js".
function App() {
return (
<div className="App">
<PrimaryBouton Type='primary' Title='Lorem Ipsum'/>
</div>
);
}
export default App;
Here is my other file :
import './PrimaryButton.css';
import React from 'react';
class PrimaryBouton extends React.Component {
render(props) {
return (
<button className={props.Type}>
<span>{props.Title}</span>
</button>
);
}
}
export default PrimaryBouton ;
My Goal is to use the props on App.js to define here the css class of my button and his span.
I don't really know how to "import my props" in this file so if someone can help me thx !
To utilize props in your case, it would look like this:
import './PrimaryButton.css';
import React from 'react';
class PrimaryBouton extends React.Component {
render() {
const { title, type } = this.props;
return (
<button className={type}>
<span>{title}</span>
</button>
);
}
}
export default PrimaryBouton;
I would recommend naming your props lowercase opposed to uppercase. There are instances where you will eventually pass props as uppercase, like passing a component via props, so naming it uppercase generally indicates that.
For example i am having a component like this,
import React from "react";
export default const App = () => {
console.log("ComponrntName i.e App in this scenario")
return (
<div>
<p>Hello World</p>
</div>
)
}
how to get component name . (i.e) App in this scenario . Thanks
You can set the displayName to a functional component like App.displayName = "AppComponent";
and inside the function you can access it with App.displayName
import React from "react";
const App = () => {
console.log("ComponrntName:", App.displayName);
return (
<div>
<p>Hello World</p>
</div>
)
}
App.displayName = "AppComponent";
export default App;
class App extends Component {
constructor(props) {
super(props);
}
}
this.constructor.name
you will get the Component
One component Landing.js has following code::
import React, { Component } from 'react'
import NewsSearch from '../NewsSearch/NewsSearch';
import NewsLatest from '../NewsLatest/NewsLatest';
import './Landing.css';
import axios from 'axios';
class Landing extends Component {
state={
newsList: []
}
componentDidMount(){
axios.get(`https://api.nytimes.com/svc/topstories/v2/home.json?api-key=7cK9FpOnC3zgoboP2CPGR3FcznEaYCJv`)
.then(res=> {
this.setState({newsList: res.data.results});
});
}
render() {
// console.log(this.state.newsList);
return (
<div className="landing text-center text-white">
<h1>News Portal</h1>
<div className="news-search">
<NewsSearch />
</div>
<div className="news-latest">
<NewsLatest newsList={this.state.newsList}/>
</div>
</div>
)
}
}
export default Landing;
When sending props to NewsLatest component, 2 values are getting passed: first as undefined and then when value comes then an array with the values.
In the "NewsLatest.js" file code is :::
import React, { Component } from 'react';
// import PropTypes from 'prop-types';
class NewsLatest extends Component {
newsTitle = (
this.props.newsList.map(item => (<h2>{item.title}</h2>))
)
render() {
console.log(this.props.newsList);
return (
<div>
<h2>News Latest....</h2>
{this.newsTitle}
</div>
);
}
}
export default NewsLatest;
Nothing is rendering on the UI. I dont know how to handle that. Kindly suggest something.
The issue you are facing is that you are not rendering anything (per se) cos newsTitle does not return anything.
In your code, newsTitle is an object but you need to make it a function.
Modifying NewsLatest should fix this though
import React, { Component } from 'react';
// import PropTypes from 'prop-types';
class NewsLatest extends Component {
newsTitle = () => (
this.props.newsList.map(item => (<h2>{item.title}</h2>))
)
render() {
console.log(this.props.newsList);
return (
<div>
<h2>News Latest....</h2>
{this.newsTitle()}
</div>
);
}
}
export default NewsLatest;
I'm working in nextjs.I have header component and in order to show header in all other pages ,overrided app.js with _app.js .Header has 2 navigation link usersList and users.
Now I want to send data from header component to another page say usersList and users on click of submit in header.How we can achieve that .
I know that we can use context .I'm using class based component don't know weather we can use context.
Is there any other solution to this problem..
Please help
header.js
class HeaderComponent extends Component {
onSearch(event){
//some code
}
render() {
return (
<div className="navbar">
<Input id="search-input" className="text-box" placeholder="Enter name or Email.." onKeyDown={($event)=>this.onSearch($event)} prefix={<Icon type="search" onClick={()=>this.onSearch} ></Icon>}></Input>
</div>
)
}
}
export default HeaderComponent
Layout.js
import React, { Component } from 'react';
import Header from './Header';
class Layout extends Component {
render () {
const { children } = this.props
return (
<div className='layout'>
<Header />
{children}
</div>
);
}
}
_app.js
import React from 'react';
import App from 'next/app';
import Layout from '../components/Layout';
export default class MyApp extends App {
render () {
const { Component, pageProps } = this.props
return (
<Layout>
<Component {...pageProps} />
</Layout>
)
}
}
userList.js
class AppUser extends Component {
render() {
return (
<Table
rowKey={data._id}
columns={this.columns1}
onExpand={this.onExpand}
dataSource={data}
/>
)
}
}
EDIT :
can we achieve it through props
You can use ReactRedux to create a store and have it accessible from all components.
https://redux.js.org/api/store [1]