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How to detect if child is clicked on parent click React

I'm using React and I have the following situation.
I have one parent div with onClick event, which takes full width and inside that div I have an image. I want to be able to know where it is clicked. Thus, I want to know if image (child) or div(parent) is clicked.
My code is as follows:
class APP extends React.Component {
constructor(props) {
super(props)
}
render() {
return (
<div className="parent" onClick={(e) => console.log("PARENT CLICK")}>
<img src="https://interactive-examples.mdn.mozilla.net/media/cc0-images/grapefruit-slice-332-332.jpg"
style={{maxWidth: "60%", maxHeight: "90%", pointerEvents: 'none', zIndex: 99999}}
onClick={e => console.log("IMAGE CLICK")}
/>
</div>
)
}
}
ReactDOM.render(<APP />, document.querySelector("#app"))
But it detects always the parent click. I tried to add z-index to the child, but I think that child can't be in front of parent.
Here is the fiddle.

class APP extends React.Component {
constructor(props) {
super(props)
}
handleclick(e){
e.stopPropagation();
console.log(e.target.tagName);
return false;
}
render() {
return (
<div className="parent" onClick={(e) => this.handleclick(e)}>
<img src="https://interactive-examples.mdn.mozilla.net/media/cc0-images/grapefruit-slice-332-332.jpg"
style={{maxWidth: "30%", maxHeight: "30%", zIndex: 99999}}
onClick={(e) => this.handleclick(e)}
/>
</div>
)
}
}
ReactDOM.render(<APP />, document.querySelector("#app"))
please note here I added e.stopPropagation() in the click event which only executes with the target element.. here you can read more about propogation
and also please remove the CSS pointerEvents: 'none' from the img tag, it works fine.
Working Fiddle

pointerEvents : none will block the pointer events.Remove that from your styling

You have pointerEvents set to none in your img's inline style object. Remove that. Can remove zIndex as well.
From CSS-Tricks:-
pointer-events:none prevents all click, state and cursor options on
the specified HTML element
You don't need e.stopPropagation() here. Just set the event handler only on parent like so (this is known as event delegation) :-
class APP extends React.Component {
constructor(props) {
super(props)
}
handleclick(e){
console.log(e.target.tagName);
}
render() {
return (
<div className="parent" onClick={this.handleclick}>
<img src="https://interactive-examples.mdn.mozilla.net/media/cc0-images/grapefruit-slice-332-332.jpg"
style={{maxWidth: "30%", maxHeight: "30%"}}
/>
</div>
)
}
}
ReactDOM.render(<APP />, document.querySelector("#app"))

Im not sure if this is the react way of doing this but in javascript you can use the event object properties to get the element that triggered it with event.target and the element that handled it with event.currentTarget.
document.querySelector('#parent').addEventListener('click', (e) => {
console.log(`clicked element is: ${e.target.id}`);
console.log(`event handler element is: ${e.currentTarget.id}`);
});
<div id='parent'>parent
<div id='child'>child</div>
</div>

As CodeBug noted above it should be enough to stop the propagation on the click event by calling (inside of the onClick function):
event.stopPropagation();

React HOC with multiple components

I want to create a React HOC that would ideally receive two components instead of one wrapped component and toggle between them. That is, in the code below, instead of <h3>component one</h3> and <h3>component two<h3>, they would each represent child components. How would I be able to accomplish this? Some psuedo code for how I would write this HOC:
<HOC>
<ComponentOne />
<ComponentTwo />
</HOC>
<HOC
componentOne={<ComponentOne />}
componentTwo={<ComponentTwo />}
/>
hoc(componentOne, componentTwo)
class HOC extends React.Component {
constructor() {
super();
this.state = {
onClick: false,
};
this.handleClick = this.handleClick.bind(this);
}
handleClick() {
this.setState({onClick: !this.state.onClick});
}
render() {
return (
<div>
<button onClick={this.handleClick}>Click Me!</button>
{
this.state.onClick ?
<h3>component one</h3> :
<h3>component two</h3>
}
</div>
);
}
}
ReactDOM.render(<HOC />, app);
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="app"></div>

I am not sure if I understood you. Why do you need it to be HOC?
If you would pass components as props like that:
<HOC
componentOne={<ComponentOne />}
componentTwo={<ComponentTwo />}
/>
Then you would be able to access them using props.
render() {
return (
<div>
<button onClick={this.handleClick}>Click Me!</button>
{
this.state.onClick ?
this.props.componentOne :
this.props.componentTwo
}
</div>
);
}

If a component has more than one child then this.props.children will be an array.
class HOC extends React.Component {
// ... rest of code ....
render() {
const { onClick } = this.state;
const { children } = this.props;
return !onClick ? children[0] : children[1];
}
}
Then use it like so:
<HOC>
<div>Child One</div>
<div>Child Two</div>
</HOC>
Obviously this will only work with two children but you could extend it by passing an integer to <HOC> through props to tell it what child to select.
Edit
After a quick look at the docs this is a better version of what I wrote above as this.props.children is not an array, it is an opaque data structure:
class HOC extends React.Component {
// ... rest of code ...
render() {
const { onClick } = this.state;
const children = React.Children.toArray(this.props.children);
return !onClick ? children[0] : children[1];
}
}

React.js: How to append a component on click?

I'm new to React and I'm puzzled on something kind of basic.
I need to append a component to the DOM after the DOM is rendered, on a click event.
My initial attempt is as follows, and it doesn't work. But it's the best thing I've thought to try. (Apologies in advance for mixing jQuery with React.)
ParentComponent = class ParentComponent extends React.Component {
constructor () {
this.addChild = this.addChild.bind(this);
}
addChild (event) {
event.preventDefault();
$("#children-pane").append(<ChildComponent/>);
}
render () {
return (
<div className="card calculator">
<p><a href="#" onClick={this.addChild}>Add Another Child Component</a></p>
<div id="children-pane">
<ChildComponent/>
</div>
</div>
);
}
};
Hopefully it's clear what I need to do, and I hope you can help me attain an appropriate solution.

Don't use jQuery to manipulate the DOM when you're using React. React components should render a representation of what they should look like given a certain state; what DOM that translates to is taken care of by React itself.
What you want to do is store the "state which determines what gets rendered" higher up the chain, and pass it down. If you are rendering n children, that state should be "owned" by whatever contains your component. eg:
class AppComponent extends React.Component {
state = {
numChildren: 0
}
render () {
const children = [];
for (var i = 0; i < this.state.numChildren; i += 1) {
children.push(<ChildComponent key={i} number={i} />);
};
return (
<ParentComponent addChild={this.onAddChild}>
{children}
</ParentComponent>
);
}
onAddChild = () => {
this.setState({
numChildren: this.state.numChildren + 1
});
}
}
const ParentComponent = props => (
<div className="card calculator">
<p><a href="#" onClick={props.addChild}>Add Another Child Component</a></p>
<div id="children-pane">
{props.children}
</div>
</div>
);
const ChildComponent = props => <div>{"I am child " + props.number}</div>;

As #Alex McMillan mentioned, use state to dictate what should be rendered in the dom.
In the example below I have an input field and I want to add a second one when the user clicks the button, the onClick event handler calls handleAddSecondInput( ) which changes inputLinkClicked to true. I am using a ternary operator to check for the truthy state, which renders the second input field
class HealthConditions extends React.Component {
constructor(props) {
super(props);
this.state = {
inputLinkClicked: false
}
}
handleAddSecondInput() {
this.setState({
inputLinkClicked: true
})
}
render() {
return(
<main id="wrapper" className="" data-reset-cookie-tab>
<div id="content" role="main">
<div className="inner-block">
<H1Heading title="Tell us about any disabilities, illnesses or ongoing conditions"/>
<InputField label="Name of condition"
InputType="text"
InputId="id-condition"
InputName="condition"
/>
{
this.state.inputLinkClicked?
<InputField label=""
InputType="text"
InputId="id-condition2"
InputName="condition2"
/>
:
<div></div>
}
<button
type="button"
className="make-button-link"
data-add-button=""
href="#"
onClick={this.handleAddSecondInput}
>
Add a condition
</button>
<FormButton buttonLabel="Next"
handleSubmit={this.handleSubmit}
linkto={
this.state.illnessOrDisability === 'true' ?
"/404"
:
"/add-your-details"
}
/>
<BackLink backLink="/add-your-details" />
</div>
</div>
</main>
);
}
}

change scrollTop in reactjs

I just learn react, and want to achieve a function :
both A,B are components, if A scroll, then B scroll
The following is my code
<A onScroll="handleScroll"></A>
//what i write now
handleScroll: function(event){
var target = event.nativeEvent.target;
//do something to change scrollTop value
target.scrollTop += 1;
// it looks the same as not use react
document.getElementById(B).scrollTop = target.scrollTop;
}
but actually I want my code like this
//what i want
<A scrollTop={this.props.scrollSeed}></A>
<B scrollTop={this.props.scrollSeed}></B>
//...
handleScroll(){
this.setState({scrollSeed: ++this.state.scrollSeed})
}
it is similar to input
<input value="this.props.value"/>
<input value="this.props.value"/>
<input ref='c' onChange={handleChange}>
//...
handleChange: function() {
// enter some code in c and then render in a and b automatically
}
In other words, I want some attribute, like scrollTop(different
form <input value={}> ,because <A scrollTop={}> doesn't work) ,is bind with some state, so that I can just use setState, and they will update by themselves.
I googled before but can't find the answser. I hope that my poor English won't confuse you.

There are a number of patterns to achieve this. This sample is what I came up with to get you up and going.
First create a component class which has an oversize element for scroll effect. When dragging the scroll bar, this component calls its handleScroll React property to notify its parent component, with the value of scrollTop.
var Elem = React.createClass({
render() {
return (
<div ref="elem"
onScroll={ this.onScroll }
style={{ width: "100px", height: "100px", overflow: "scroll" }}>
<div style={{ width: "100%", height: "200%" }}>Hello!</div>
</div>
);
},
componentDidUpdate() {
this.refs.elem.scrollTop = this.props.scrollTop;
},
onScroll() {
this.props.handleScroll( this.refs.elem.scrollTop );
}
});
The parent component, aka wrapper, keeps the scroll top value in its state. Its handleScroll is passed to the child components as callback. Any scroll on the child elements triggers the callback, sets the state, results in a redraw, and updates the child component.
var Wrapper = React.createClass({
getInitialState() {
return {
scrollTop: 0
}
},
render() {
return (
<div>
<Elem scrollTop={ this.state.scrollTop } handleScroll={ this.handleScroll } />
<Elem scrollTop={ this.state.scrollTop } handleScroll={ this.handleScroll } />
</div>
);
},
handleScroll( scrollTop ) {
this.setState({ scrollTop });
}
});
And render the wrapper, presuming an existing <div id="container"></div>.
ReactDOM.render(
<Wrapper />,
document.getElementById('container')
);

2019's answer
First, the fix:
const resetScrollEffect = ({ element }) => {
element.current.getScrollableNode().children[0].scrollTop = 0
}
const Table = props => {
const tableRef = useRef(null)
useEffect(() => resetScrollEffect({ element: tableRef }), [])
return (
<Component>
<FlatList
ref={someRef}
/>
</Component>
)
}
Second, a little explanation:
Idk what is your reason why you got here but I have used flex-direction: column-reverse for my FlatList (it's a list of elements). And I need this property for z-index purposes. However, browsers set their scroll position to the end for such elements (tables, chats, etc.) - this may be useful but I don't need that in my case.
Also, example is shown using React Hooks, but you can use older more traditional way of defining refs

this.refs is deprecated. use reactjs.org/docs/refs-and-the-dom.html#creating-refs
import React from 'react';
class SomeComponent extends React.Component {
constructor(props) {
super(props);
this.resultsDiv = React.createRef();
}
someFunction(){
this.resultsDiv.current.scrollIntoView({behavior: 'smooth'});
// alternative:
// this.resultsDiv.current.scrollTop = 0;
}
render() {
return (
<div ref={this.resultsDiv} />
);
}
}
export default SomeComponent;

Here's an updated version of Season's answer, including a runnable snippet. It uses the recommended method for creating refs.
class Editor extends React.Component {
constructor(props) {
super(props);
this.content = React.createRef();
this.handleScroll = this.handleScroll.bind(this);
}
componentDidUpdate() {
this.content.current.scrollTop = this.props.scrollTop;
}
handleScroll() {
this.props.onScroll( this.content.current.scrollTop );
}
render() {
let text = 'a\n\nb\n\nc\n\nd\n\ne\n\nf\n\ng';
return <textarea
ref={this.content}
value={text}
rows="10"
cols="30"
onScroll={this.handleScroll}/>;
}
}
class App extends React.Component {
constructor(props) {
super(props);
this.state = {scrollTop: 0};
this.handleScroll = this.handleScroll.bind(this);
}
handleScroll(scrollTop) {
this.setState({scrollTop: scrollTop});
}
render() {
return <table><tbody>
<tr><th>Foo</th><th>Bar</th></tr>
<tr>
<td><Editor
scrollTop={this.state.scrollTop}
onScroll={this.handleScroll}/></td>
<td><Editor
scrollTop={this.state.scrollTop}
onScroll={this.handleScroll}/></td>
</tr>
</tbody></table>;
}
}
ReactDOM.render(
<App/>,
document.getElementById('root')
);
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="root"></div>

Show or hide element in React

I am messing around with React.js for the first time and cannot find a way to show or hide something on a page via click event. I am not loading any other library to the page, so I am looking for some native way using the React library. This is what I have so far. I would like to show the results div when the click event fires.
var Search= React.createClass({
handleClick: function (event) {
console.log(this.prop);
},
render: function () {
return (
<div className="date-range">
<input type="submit" value="Search" onClick={this.handleClick} />
</div>
);
}
});
var Results = React.createClass({
render: function () {
return (
<div id="results" className="search-results">
Some Results
</div>
);
}
});
React.renderComponent(<Search /> , document.body);

React circa 2020
In the onClick callback, call the state hook's setter function to update the state and re-render:
const Search = () => {
const [showResults, setShowResults] = React.useState(false)
const onClick = () => setShowResults(true)
return (
<div>
<input type="submit" value="Search" onClick={onClick} />
{ showResults ? <Results /> : null }
</div>
)
}
const Results = () => (
<div id="results" className="search-results">
Some Results
</div>
)
ReactDOM.render(<Search />, document.querySelector("#container"))
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.1/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.1/umd/react-dom.production.min.js"></script>
<div id="container">
<!-- This element's contents will be replaced with your component. -->
</div>
JSFiddle
React circa 2014
The key is to update the state of the component in the click handler using setState. When the state changes get applied, the render method gets called again with the new state:
var Search = React.createClass({
getInitialState: function() {
return { showResults: false };
},
onClick: function() {
this.setState({ showResults: true });
},
render: function() {
return (
<div>
<input type="submit" value="Search" onClick={this.onClick} />
{ this.state.showResults ? <Results /> : null }
</div>
);
}
});
var Results = React.createClass({
render: function() {
return (
<div id="results" className="search-results">
Some Results
</div>
);
}
});
ReactDOM.render( <Search /> , document.getElementById('container'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.2/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/15.6.2/react-dom.min.js"></script>
<div id="container">
<!-- This element's contents will be replaced with your component. -->
</div>
JSFiddle

<style type="text/css">
.hidden { display:none; }
</style>
const Example = props =>
<div className={props.shouldHide? 'hidden' : undefined}>Hello</div>

Here is an alternative syntax for the ternary operator:
{ this.state.showMyComponent ? <MyComponent /> : null }
is equivalent to:
{ this.state.showMyComponent && <MyComponent /> }
Learn why
Also alternative syntax with display: 'none';
<MyComponent style={this.state.showMyComponent ? {} : { display: 'none' }} />
However, if you overuse display: 'none', this leads to DOM pollution and ultimately slows down your application.

Here is my approach.
import React, { useState } from 'react';
function ToggleBox({ title, children }) {
const [isOpened, setIsOpened] = useState(false);
function toggle() {
setIsOpened(wasOpened => !wasOpened);
}
return (
<div className="box">
<div className="boxTitle" onClick={toggle}>
{title}
</div>
{isOpened && (
<div className="boxContent">
{children}
</div>
)}
</div>
);
}
In code above, to achieve this, I'm using code like:
{opened && <SomeElement />}
That will render SomeElement only if opened is true. It works because of the way how JavaScript resolve logical conditions:
true && true && 2; // will output 2
true && false && 2; // will output false
true && 'some string'; // will output 'some string'
opened && <SomeElement />; // will output SomeElement if `opened` is true, will output false otherwise (and false will be ignored by react during rendering)
// be careful with 'falsy' values eg
const someValue = [];
someValue.length && <SomeElement /> // will output 0, which will be rednered by react
// it'll be better to:
someValue.length > 0 && <SomeElement /> // will render nothing as we cast the value to boolean
Reasons for using this approach instead of CSS 'display: none';
While it might be 'cheaper' to hide an element with CSS - in such case 'hidden' element is still 'alive' in react world (which might make it actually way more expensive)
it means that if props of the parent element (eg. <TabView>) will change - even if you see only one tab, all 5 tabs will get re-rendered
the hidden element might still have some lifecycle methods running - eg. it might fetch some data from the server after every update even tho it's not visible
the hidden element might crash the app if it'll receive incorrect data. It might happen as you can 'forget' about invisible nodes when updating the state
you might by mistake set wrong 'display' style when making element visible - eg. some div is 'display: flex' by default, but you'll set 'display: block' by mistake with display: invisible ? 'block' : 'none' which might break the layout
using someBoolean && <SomeNode /> is very simple to understand and reason about, especially if your logic related to displaying something or not gets complex
in many cases, you want to 'reset' element state when it re-appears. eg. you might have a slider that you want to set to initial position every time it's shown. (if that's desired behavior to keep previous element state, even if it's hidden, which IMO is rare - I'd indeed consider using CSS if remembering this state in a different way would be complicated)

with the newest version react 0.11 you can also just return null to have no content rendered.
Rendering to null

This is a nice way to make use of the virtual DOM:
class Toggle extends React.Component {
state = {
show: true,
}
toggle = () => this.setState((currentState) => ({show: !currentState.show}));
render() {
return (
<div>
<button onClick={this.toggle}>
toggle: {this.state.show ? 'show' : 'hide'}
</button>
{this.state.show && <div>Hi there</div>}
</div>
);
}
}
Example here
Using React hooks:
const Toggle = () => {
const [show, toggleShow] = React.useState(true);
return (
<div>
<button
onClick={() => toggleShow(!show)}
>
toggle: {show ? 'show' : 'hide'}
</button>
{show && <div>Hi there</div>}
</div>
)
}
Example here

I created a small component that handles this for you: react-toggle-display
It sets the style attribute to display: none !important based on the hide or show props.
Example usage:
var ToggleDisplay = require('react-toggle-display');
var Search = React.createClass({
getInitialState: function() {
return { showResults: false };
},
onClick: function() {
this.setState({ showResults: true });
},
render: function() {
return (
<div>
<input type="submit" value="Search" onClick={this.onClick} />
<ToggleDisplay show={this.state.showResults}>
<Results />
</ToggleDisplay>
</div>
);
}
});
var Results = React.createClass({
render: function() {
return (
<div id="results" className="search-results">
Some Results
</div>
);
}
});
React.renderComponent(<Search />, document.body);

There are several great answers already, but I don't think they've been explained very well and several of the methods given contain some gotchas that might trip people up. So I'm going to go over the three main ways (plus one off-topic option) to do this and explain the pros and cons. I'm mostly writing this because Option 1 was recommended a lot and there's a lot of potential issues with that option if not used correctly.
Option 1: Conditional Rendering in the parent.
I don't like this method unless you're only going to render the component one time and leave it there. The issue is it will cause react to create the component from scratch every time you toggle the visibility.
Here's the example. LogoutButton or LoginButton are being conditionally rendered in the parent LoginControl. If you run this you'll notice the constructor is getting called on each button click. https://codepen.io/Kelnor/pen/LzPdpN?editors=1111
class LoginControl extends React.Component {
constructor(props) {
super(props);
this.handleLoginClick = this.handleLoginClick.bind(this);
this.handleLogoutClick = this.handleLogoutClick.bind(this);
this.state = {isLoggedIn: false};
}
handleLoginClick() {
this.setState({isLoggedIn: true});
}
handleLogoutClick() {
this.setState({isLoggedIn: false});
}
render() {
const isLoggedIn = this.state.isLoggedIn;
let button = null;
if (isLoggedIn) {
button = <LogoutButton onClick={this.handleLogoutClick} />;
} else {
button = <LoginButton onClick={this.handleLoginClick} />;
}
return (
<div>
<Greeting isLoggedIn={isLoggedIn} />
{button}
</div>
);
}
}
class LogoutButton extends React.Component{
constructor(props, context){
super(props, context)
console.log('created logout button');
}
render(){
return (
<button onClick={this.props.onClick}>
Logout
</button>
);
}
}
class LoginButton extends React.Component{
constructor(props, context){
super(props, context)
console.log('created login button');
}
render(){
return (
<button onClick={this.props.onClick}>
Login
</button>
);
}
}
function UserGreeting(props) {
return <h1>Welcome back!</h1>;
}
function GuestGreeting(props) {
return <h1>Please sign up.</h1>;
}
function Greeting(props) {
const isLoggedIn = props.isLoggedIn;
if (isLoggedIn) {
return <UserGreeting />;
}
return <GuestGreeting />;
}
ReactDOM.render(
<LoginControl />,
document.getElementById('root')
);
Now React is pretty quick at creating components from scratch. However, it still has to call your code when creating it. So if your constructor, componentDidMount, render, etc code is expensive, then it'll significantly slow down showing the component. It also means you cannot use this with stateful components where you want the state to be preserved when hidden (and restored when displayed.) The one advantage is that the hidden component isn't created at all until it's selected. So hidden components won't delay your initial page load. There may also be cases where you WANT a stateful component to reset when toggled. In which case this is your best option.
Option 2: Conditional Rendering in the child
This creates both components once. Then short circuits the rest of the render code if the component is hidden. You can also short circuit other logic in other methods using the visible prop. Notice the console.log in the codepen page. https://codepen.io/Kelnor/pen/YrKaWZ?editors=0011
class LoginControl extends React.Component {
constructor(props) {
super(props);
this.handleLoginClick = this.handleLoginClick.bind(this);
this.handleLogoutClick = this.handleLogoutClick.bind(this);
this.state = {isLoggedIn: false};
}
handleLoginClick() {
this.setState({isLoggedIn: true});
}
handleLogoutClick() {
this.setState({isLoggedIn: false});
}
render() {
const isLoggedIn = this.state.isLoggedIn;
return (
<div>
<Greeting isLoggedIn={isLoggedIn} />
<LoginButton isLoggedIn={isLoggedIn} onClick={this.handleLoginClick}/>
<LogoutButton isLoggedIn={isLoggedIn} onClick={this.handleLogoutClick}/>
</div>
);
}
}
class LogoutButton extends React.Component{
constructor(props, context){
super(props, context)
console.log('created logout button');
}
render(){
if(!this.props.isLoggedIn){
return null;
}
return (
<button onClick={this.props.onClick}>
Logout
</button>
);
}
}
class LoginButton extends React.Component{
constructor(props, context){
super(props, context)
console.log('created login button');
}
render(){
if(this.props.isLoggedIn){
return null;
}
return (
<button onClick={this.props.onClick}>
Login
</button>
);
}
}
function UserGreeting(props) {
return <h1>Welcome back!</h1>;
}
function GuestGreeting(props) {
return <h1>Please sign up.</h1>;
}
function Greeting(props) {
const isLoggedIn = props.isLoggedIn;
if (isLoggedIn) {
return <UserGreeting />;
}
return <GuestGreeting />;
}
ReactDOM.render(
<LoginControl />,
document.getElementById('root')
);
Now, if the initialization logic is quick and the children are stateless, then you won't see a difference in performance or functionality. However, why make React create a brand new component every toggle anyway? If the initialization is expensive however, Option 1 will run it every time you toggle a component which will slow the page down when switching. Option 2 will run all of the component's inits on first page load. Slowing down that first load. Should note again. If you're just showing the component one time based on a condition and not toggling it, or you want it to reset when toggledm, then Option 1 is fine and probably the best option.
If slow page load is a problem however, it means you've got expensive code in a lifecycle method and that's generally not a good idea. You can, and probably should, solve the slow page load by moving the expensive code out of the lifecycle methods. Move it to an async function that's kicked off by ComponentDidMount and have the callback put it in a state variable with setState(). If the state variable is null and the component is visible then have the render function return a placeholder. Otherwise render the data. That way the page will load quickly and populate the tabs as they load. You can also move the logic into the parent and push the results to the children as props. That way you can prioritize which tabs get loaded first. Or cache the results and only run the logic the first time a component is shown.
Option 3: Class Hiding
Class hiding is probably the easiest to implement. As mentioned you just create a CSS class with display: none and assign the class based on prop. The downside is the entire code of every hidden component is called and all hidden components are attached to the DOM. (Option 1 doesn't create the hidden components at all. And Option 2 short circuits unnecessary code when the component is hidden and removes the component from the DOM completely.) It appears this is faster at toggling visibility according some tests done by commenters on other answers but I can't speak to that.
Option 4: One component but change Props. Or maybe no component at all and cache HTML.
This one won't work for every application and it's off topic because it's not about hiding components, but it might be a better solution for some use cases than hiding. Let's say you have tabs. It might be possible to write one React Component and just use the props to change what's displayed in the tab. You could also save the JSX to state variables and use a prop to decide which JSX to return in the render function. If the JSX has to be generated then do it and cache it in the parent and send the correct one as a prop. Or generate in the child and cache it in the child's state and use props to select the active one.

You set a boolean value in the state (e.g. 'show)', and then do:
var style = {};
if (!this.state.show) {
style.display = 'none'
}
return <div style={style}>...</div>

A simple method to show/hide elements in React using Hooks
const [showText, setShowText] = useState(false);
Now, let's add some logic to our render method:
{showText && <div>This text will show!</div>}
And
onClick={() => setShowText(!showText)}
Good job.

I was able to use css property "hidden". Don't know about possible drawbacks.
export default function App() {
const [hidden, setHidden] = useState(false);
return (
<div>
<button onClick={() => setHidden(!hidden)}>HIDE</button>
<div hidden={hidden}>hidden component</div>
</div>
);
}

Best practice is below according to the documentation:
{this.state.showFooter && <Footer />}
Render the element only when the state is valid.

Simple hide/show example with React Hooks: (srry about no fiddle)
const Example = () => {
const [show, setShow] = useState(false);
return (
<div>
<p>Show state: {show}</p>
{show ? (
<p>You can see me!</p>
) : null}
<button onClick={() => setShow(!show)}>
</div>
);
};
export default Example;

class FormPage extends React.Component{
constructor(props){
super(props);
this.state = {
hidediv: false
}
}
handleClick = (){
this.setState({
hidediv: true
});
}
render(){
return(
<div>
<div className="date-range" hidden = {this.state.hidediv}>
<input type="submit" value="Search" onClick={this.handleClick} />
</div>
<div id="results" className="search-results" hidden = {!this.state.hidediv}>
Some Results
</div>
</div>
);
}
}

I start with this statement from the React team:
In React, you can create distinct components that encapsulate behaviour
you need. Then, you can render only some of them, depending on the
state of your application.
Conditional rendering in React works the same way conditions work in
JavaScript. Use JavaScript operators like if or the conditional
operator to create elements representing the current state, and let
React update the UI to match them.
You basically need to show the component when the button gets clicked, you can do it two ways, using pure React or using CSS, using pure React way, you can do something like below code in your case, so in the first run, results are not showing as hideResults is true, but by clicking on the button, state gonna change and hideResults is false and the component get rendered again with the new value conditions, this is very common use of changing component view in React...
var Search = React.createClass({
getInitialState: function() {
return { hideResults: true };
},
handleClick: function() {
this.setState({ hideResults: false });
},
render: function() {
return (
<div>
<input type="submit" value="Search" onClick={this.handleClick} />
{ !this.state.hideResults && <Results /> }
</div> );
}
});
var Results = React.createClass({
render: function() {
return (
<div id="results" className="search-results">
Some Results
</div>);
}
});
ReactDOM.render(<Search />, document.body);
If you want to do further study in conditional rendering in React, have a look here.

class Toggle extends React.Component {
state = {
show: true,
}
render() {
const {show} = this.state;
return (
<div>
<button onClick={()=> this.setState({show: !show })}>
toggle: {show ? 'show' : 'hide'}
</button>
{show && <div>Hi there</div>}
</div>
);
}
}

If you would like to see how to TOGGLE the display of a component checkout this fiddle.
http://jsfiddle.net/mnoster/kb3gN/16387/
var Search = React.createClass({
getInitialState: function() {
return {
shouldHide:false
};
},
onClick: function() {
console.log("onclick");
if(!this.state.shouldHide){
this.setState({
shouldHide: true
})
}else{
this.setState({
shouldHide: false
})
}
},
render: function() {
return (
<div>
<button onClick={this.onClick}>click me</button>
<p className={this.state.shouldHide ? 'hidden' : ''} >yoyoyoyoyo</p>
</div>
);
}
});
ReactDOM.render( <Search /> , document.getElementById('container'));

Use ref and manipulate CSS
One way could be to use React's ref and manipulate CSS class using the browser's API. Its benefit is to avoid rerendering in React if the sole purpose is to hide/show some DOM element on the click of a button.
// Parent.jsx
import React, { Component } from 'react'
export default class Parent extends Component {
constructor () {
this.childContainer = React.createRef()
}
toggleChild = () => {
this.childContainer.current.classList.toggle('hidden')
}
render () {
return (
...
<button onClick={this.toggleChild}>Toggle Child</button>
<div ref={this.childContainer}>
<SomeChildComponent/>
</div>
...
);
}
}
// styles.css
.hidden {
display: none;
}
PS Correct me if I am wrong. :)

In some cases higher order component might be useful:
Create higher order component:
export var HidableComponent = (ComposedComponent) => class extends React.Component {
render() {
if ((this.props.shouldHide!=null && this.props.shouldHide()) || this.props.hidden)
return null;
return <ComposedComponent {...this.props} />;
}
};
Extend your own component:
export const MyComp= HidableComponent(MyCompBasic);
Then you can use it like this:
<MyComp hidden={true} ... />
<MyComp shouldHide={this.props.useSomeFunctionHere} ... />
This reduces a bit boilerplate and enforces sticking to naming conventions, however please be aware of that MyComp will still be instantiated - the way to omit is was mentioned earlier:
{ !hidden && <MyComp ... /> }

If you use bootstrap 4, you can hide element that way
className={this.state.hideElement ? "invisible" : "visible"}

Use rc-if-else module
npm install --save rc-if-else
import React from 'react';
import { If } from 'rc-if-else';
class App extends React.Component {
render() {
return (
<If condition={this.props.showResult}>
Some Results
</If>
);
}
}

Use this lean and short syntax:
{ this.state.show && <MyCustomComponent /> }

Here comes the simple, effective and best solution with a Classless React Component for show/hide the elements. Use of React-Hooks which is available in the latest create-react-app project that uses React 16
import React, {useState} from 'react';
function RenderPara(){
const [showDetail,setShowDetail] = useState(false);
const handleToggle = () => setShowDetail(!showDetail);
return (
<React.Fragment>
<h3>
Hiding some stuffs
</h3>
<button onClick={handleToggle}>Toggle View</button>
{showDetail && <p>
There are lot of other stuffs too
</p>}
</React.Fragment>)
}
export default RenderPara;
Happy Coding :)

//use ternary condition
{ this.state.yourState ? <MyComponent /> : null }
{ this.state.yourState && <MyComponent /> }
{ this.state.yourState == 'string' ? <MyComponent /> : ''}
{ this.state.yourState == 'string' && <MyComponent /> }
//Normal condition
if(this.state.yourState){
return <MyComponent />
}else{
return null;
}
<button onClick={()=>this.setState({yourState: !this.props.yourState}>Toggle View</button>

Just figure out a new and magic way with using(useReducer) for functional components
const [state, handleChangeState] = useReducer((state) => !state, false);
change state

This can also be achieved like this (very easy way)
class app extends Component {
state = {
show: false
};
toggle= () => {
var res = this.state.show;
this.setState({ show: !res });
};
render() {
return(
<button onClick={ this.toggle }> Toggle </button>
{
this.state.show ? (<div> HELLO </div>) : null
}
);
}

this example shows how you can switch between components by using a toggle which switches after every 1sec
import React ,{Fragment,Component} from "react";
import ReactDOM from "react-dom";
import "./styles.css";
const Component1 = () =>(
<div>
<img
src="https://i.pinimg.com/originals/58/df/1d/58df1d8bf372ade04781b8d4b2549ee6.jpg" />
</div>
)
const Component2 = () => {
return (
<div>
<img
src="http://www.chinabuddhismencyclopedia.com/en/images/thumb/2/2e/12ccse.jpg/250px-
12ccse.jpg" />
</div>
)
}
class App extends Component {
constructor(props) {
super(props);
this.state = {
toggleFlag:false
}
}
timer=()=> {
this.setState({toggleFlag:!this.state.toggleFlag})
}
componentDidMount() {
setInterval(this.timer, 1000);
}
render(){
let { toggleFlag} = this.state
return (
<Fragment>
{toggleFlag ? <Component1 /> : <Component2 />}
</Fragment>
)
}
}
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

The application of states and effects has and must be encapsulated in the same component, for this reason, there is nothing better than creating a custom component as a hook to solve in this case whether to make particular blocks or elements visible or invisible.
// hooks/useOnScreen.js
import { useState, useEffect } from "react"
const useOnScreen = (ref, rootMargin = "0px") => {
const [isVisible, setIsVisible] = useState(false)
useEffect(() => {
const observer = new IntersectionObserver(
([entry]) => {
setIsVisible(entry.isIntersecting)
},
{
rootMargin
}
);
const currentElement = ref?.current
if (currentElement) {
observer.observe(currentElement)
}
return () => {
observer.unobserve(currentElement)
}
}, [])
return isVisible
}
export default useOnScreen
Then the custom hook is embedded inside the component
import React, { useRef } from "react";
import useOnScreen from "hooks/useOnScreen";
const MyPage = () => {
const ref = useRef(null)
const isVisible = useOnScreen(ref)
const onClick = () => {
console.log("isVisible", isVisible)
}
return (
<div ref={ref}>
<p isVisible={isVisible}>
Something is visible
</p>
<a
href="#"
onClick={(e) => {
e.preventDefault();
onClick(onClick)
}}
>
Review
</a>
</div>
)
}
export default MyPage
The ref variable, controlled by the useRef hook, allows us to capture the location in the DOM of the block that we want to control, then the isVisible variable, controlled by the useOnScreen hook, allows us to make the inside the block I signal by the useRef hook.
I believe that this implementation of the useState, useEfect, and useRef hooks allows you to avoid component rendering by separating them using custom hooks.
Hoping that this knowledge will be of use to you.

It is very simple to hide and show the elements in react.
There are multiple ways but I will show you two.
Way 1:
const [isVisible, setVisible] = useState(false)
let onHideShowClick = () =>{
setVisible(!isVisible)
}
return (<div>
<Button onClick={onHideShowClick} >Hide/Show</Button>
{(isVisible) ? <p>Hello World</p> : ""}
</div>)
Way 2:
const [isVisible, setVisible] = useState(false)
let onHideShowClick = () =>{
setVisible(!isVisible)
}
return (<div>
<Button onClick={onHideShowClick} >Hide/Show</Button>
<p style={{display: (isVisible) ? 'block' : 'none'}}>Hello World</p>
</div>)
It is just working like if and else.
In Way one, it will remove and re-render elements in Dom.
In the Second way you are just displaying elements as false or true.
Thank you.

You've to do the small change in the code for continuously hiding and showing
const onClick = () => {setShowResults(!showResults}
Problem will be solved
const Search = () => {
const [showResults, setShowResults] = React.useState(false)
const onClick = () => setShowResults(true)
const onClick = () => {setShowResults(!showResults}
return (
<div>
<input type="submit" value="Search" onClick={onClick} />
{ showResults ? <Results /> : null }
</div>
)
}
const Results = () => (
<div id="results" className="search-results">
Some Results
</div>
)
ReactDOM.render(<Search />, document.querySelector("#container"))
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.1/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.1/umd/react-dom.production.min.js"></script>
<div id="container">
<!-- This element's contents will be replaced with your component. -->
</div>
```