How to dynamically track width/height of div in React.js - css

I need a help with my work task: I have some div block with following styles:
.main-div {
width: 500px;
height: 400px;
border: 1px solid #000;
resize: both;
overflow: hidden;
}
And some React Component:
import React, { useState } from "react";
export const SomeComponent = () => {
const [width, setWidth] = useState();
const [height, setHeight] = useState();
return (
<div className="main-div">
<p>Block width: {width}, height: {height} </p>
</div>
)
}
How can I get dynamically width/height of resizing div? I mean i have to keep track of the block dimension in the process of resizing.

You could combine ResizeObserver, useEffect, and useRef:
ResizeObserver allows you to observe a HTML element and to execute an event handler every time it gets resized;
useEffect is executed right after the component mounted, so it is the right place to attach the observer to your div, and to disconnect it when the component is going to unmount via the returned function;
useRef creates a reference through to a child.
import React, { useState, useEffect, useRef } from "react";
export const SomeComponent = () => {
const [width, setWidth] = useState();
const [height, setHeight] = useState();
// useRef allows us to "store" the div in a constant,
// and to access it via observedDiv.current
const observedDiv = useRef(null);
// we also instantiate the resizeObserver and we pass
// the event handler to the constructor
const resizeObserver = new ResizeObserver(handleElementResized);
useEffect(() => {
// the code in useEffect will be executed when the component
// has mounted, so we are certain observedDiv.current will contain
// the div we want to observe
resizeObserver.observe(observedDiv.current);
// if useEffect returns a function, it is called right before the
// component unmounts, so it is the right place to stop observing
// the div
return function cleanup() {
resizeObserver.disconnect();
}
}
const handleElementResized = () => {
if(observedDiv.current.offsetWidth !== width) {
setWidth(observedDiv.current.offsetWidth);
}
if(observedDiv.current.offsetHeight !== height) {
setHeight(observedDiv.current.offsetHeight);
}
}
return (
<div className="main-div" ref={observedDiv}>
<p>Block width: {width}, height: {height} </p>
</div>
)
}
Sources
ResizeObserver:
API
Browser compatibility
useEffect hook
useRef hook

Related

How to change style just one element that clicked in map React?

I want to scale only one element in the map when clicking on the picture. I read that I have to use an index but I don't know how to do it. I also saw how to do it in inline "onclick" by passing index there. But I want to do it with separated function.
Here is the code :
import './App.css';
import { useSelector, useDispatch } from 'react-redux';
import { useEffect, useState } from 'react';
import { birds, mountains,trees, search } from './features/slices/photoSlice';
function App() {
const url = useSelector((state)=>state.url)
const dispatch = useDispatch()
const [photos, setPhoto] = useState('')
const [scale, setScale] = useState(false)
const [photoindex, setPhotoindex] = useState(0)
useEffect(()=>{
fetch(url).then(res=>res.json()).then(data=>setPhoto(data))
},[url])
const handleSearch = (e) =>{
if(e.key==='Enter'){
e.preventDefault()
dispatch(search(e.target.value))
}
}
const handleClickOnPicture = (e) => {
if(e){
setScale(!scale)
}
}
return (
<div className="App">
// Problem is here below:
{photos?photos.hits.map((photo, index)=>{
return <img className={scale?'m-5 h-80 scale-125':'m-5 h-80'} onClick={handleClickOnPicture} key={photo.webformatURL} src={photo.webformatURL}/>
}):""}
</div>
</div>
</div>
);
}
export default App;
I removed half of the code, so you will see only the problem.
use event.target.classname to add/remove classes
const handleClickOnPicture = (e) => {
if(!e.target.classList.contains('scale-125')){
e.target.classList.add('scale-125')
}
else{
e.target.classList.remove('scale-125')
}
}
<img className='m-5 h-80' onClick={handleClickOnPicture} key={photo.webformatURL} src={photo.webformatURL}/>

detect click outside of react component [duplicate]

I'm looking for a way to detect if a click event happened outside of a component, as described in this article. jQuery closest() is used to see if the target from a click event has the dom element as one of its parents. If there is a match the click event belongs to one of the children and is thus not considered to be outside of the component.
So in my component, I want to attach a click handler to the window. When the handler fires I need to compare the target with the dom children of my component.
The click event contains properties like "path" which seems to hold the dom path that the event has traveled. I'm not sure what to compare or how to best traverse it, and I'm thinking someone must have already put that in a clever utility function... No?
The following solution uses ES6 and follows best practices for binding as well as setting the ref through a method.
To see it in action:
Hooks Implementation
Class Implementation After React 16.3
Class Implementation Before React 16.3
Hooks Implementation:
import React, { useRef, useEffect } from "react";
/**
* Hook that alerts clicks outside of the passed ref
*/
function useOutsideAlerter(ref) {
useEffect(() => {
/**
* Alert if clicked on outside of element
*/
function handleClickOutside(event) {
if (ref.current && !ref.current.contains(event.target)) {
alert("You clicked outside of me!");
}
}
// Bind the event listener
document.addEventListener("mousedown", handleClickOutside);
return () => {
// Unbind the event listener on clean up
document.removeEventListener("mousedown", handleClickOutside);
};
}, [ref]);
}
/**
* Component that alerts if you click outside of it
*/
export default function OutsideAlerter(props) {
const wrapperRef = useRef(null);
useOutsideAlerter(wrapperRef);
return <div ref={wrapperRef}>{props.children}</div>;
}
Class Implementation:
After 16.3
import React, { Component } from "react";
/**
* Component that alerts if you click outside of it
*/
export default class OutsideAlerter extends Component {
constructor(props) {
super(props);
this.wrapperRef = React.createRef();
this.handleClickOutside = this.handleClickOutside.bind(this);
}
componentDidMount() {
document.addEventListener("mousedown", this.handleClickOutside);
}
componentWillUnmount() {
document.removeEventListener("mousedown", this.handleClickOutside);
}
/**
* Alert if clicked on outside of element
*/
handleClickOutside(event) {
if (this.wrapperRef && !this.wrapperRef.current.contains(event.target)) {
alert("You clicked outside of me!");
}
}
render() {
return <div ref={this.wrapperRef}>{this.props.children}</div>;
}
}
Before 16.3
import React, { Component } from "react";
/**
* Component that alerts if you click outside of it
*/
export default class OutsideAlerter extends Component {
constructor(props) {
super(props);
this.setWrapperRef = this.setWrapperRef.bind(this);
this.handleClickOutside = this.handleClickOutside.bind(this);
}
componentDidMount() {
document.addEventListener("mousedown", this.handleClickOutside);
}
componentWillUnmount() {
document.removeEventListener("mousedown", this.handleClickOutside);
}
/**
* Set the wrapper ref
*/
setWrapperRef(node) {
this.wrapperRef = node;
}
/**
* Alert if clicked on outside of element
*/
handleClickOutside(event) {
if (this.wrapperRef && !this.wrapperRef.contains(event.target)) {
alert("You clicked outside of me!");
}
}
render() {
return <div ref={this.setWrapperRef}>{this.props.children}</div>;
}
}
I was stuck on the same issue. I am a bit late to the party here, but for me this is a really good solution. Hopefully it will be of help to someone else. You need to import findDOMNode from react-dom
import ReactDOM from 'react-dom';
// ... ✂
componentDidMount() {
document.addEventListener('click', this.handleClickOutside, true);
}
componentWillUnmount() {
document.removeEventListener('click', this.handleClickOutside, true);
}
handleClickOutside = event => {
const domNode = ReactDOM.findDOMNode(this);
if (!domNode || !domNode.contains(event.target)) {
this.setState({
visible: false
});
}
}
React Hooks Approach (16.8 +)
You can create a reusable hook called useComponentVisible.
import { useState, useEffect, useRef } from 'react';
export default function useComponentVisible(initialIsVisible) {
const [isComponentVisible, setIsComponentVisible] = useState(initialIsVisible);
const ref = useRef(null);
const handleClickOutside = (event) => {
if (ref.current && !ref.current.contains(event.target)) {
setIsComponentVisible(false);
}
};
useEffect(() => {
document.addEventListener('click', handleClickOutside, true);
return () => {
document.removeEventListener('click', handleClickOutside, true);
};
}, []);
return { ref, isComponentVisible, setIsComponentVisible };
}
Then in the component you wish to add the functionality to do the following:
const DropDown = () => {
const { ref, isComponentVisible } = useComponentVisible(true);
return (
<div ref={ref}>
{isComponentVisible && (<p>Dropdown Component</p>)}
</div>
);
}
Find a codesandbox example here.
2021 Update:
It has bee a while since I added this response, and since it still seems to garner some interest, I thought I would update it to a more current React version. On 2021, this is how I would write this component:
import React, { useState } from "react";
import "./DropDown.css";
export function DropDown({ options, callback }) {
const [selected, setSelected] = useState("");
const [expanded, setExpanded] = useState(false);
function expand() {
setExpanded(true);
}
function close() {
setExpanded(false);
}
function select(event) {
const value = event.target.textContent;
callback(value);
close();
setSelected(value);
}
return (
<div className="dropdown" tabIndex={0} onFocus={expand} onBlur={close} >
<div>{selected}</div>
{expanded ? (
<div className={"dropdown-options-list"}>
{options.map((O) => (
<div className={"dropdown-option"} onClick={select}>
{O}
</div>
))}
</div>
) : null}
</div>
);
}
Original Answer (2016):
Here is the solution that best worked for me without attaching events to the container:
Certain HTML elements can have what is known as "focus", for example input elements. Those elements will also respond to the blur event, when they lose that focus.
To give any element the capacity to have focus, just make sure its tabindex attribute is set to anything other than -1. In regular HTML that would be by setting the tabindex attribute, but in React you have to use tabIndex (note the capital I).
You can also do it via JavaScript with element.setAttribute('tabindex',0)
This is what I was using it for, to make a custom DropDown menu.
var DropDownMenu = React.createClass({
getInitialState: function(){
return {
expanded: false
}
},
expand: function(){
this.setState({expanded: true});
},
collapse: function(){
this.setState({expanded: false});
},
render: function(){
if(this.state.expanded){
var dropdown = ...; //the dropdown content
} else {
var dropdown = undefined;
}
return (
<div className="dropDownMenu" tabIndex="0" onBlur={ this.collapse } >
<div className="currentValue" onClick={this.expand}>
{this.props.displayValue}
</div>
{dropdown}
</div>
);
}
});
After trying many methods here, I decided to use github.com/Pomax/react-onclickoutside because of how complete it is.
I installed the module via npm and imported it into my component:
import onClickOutside from 'react-onclickoutside'
Then, in my component class I defined the handleClickOutside method:
handleClickOutside = () => {
console.log('onClickOutside() method called')
}
And when exporting my component I wrapped it in onClickOutside():
export default onClickOutside(NameOfComponent)
That's it.
Hook implementation based on Tanner Linsley's excellent talk at JSConf Hawaii 2020:
useOuterClick API
const Client = () => {
const innerRef = useOuterClick(ev => {/*event handler code on outer click*/});
return <div ref={innerRef}> Inside </div>
};
Implementation
function useOuterClick(callback) {
const callbackRef = useRef(); // initialize mutable ref, which stores callback
const innerRef = useRef(); // returned to client, who marks "border" element
// update cb on each render, so second useEffect has access to current value
useEffect(() => { callbackRef.current = callback; });
useEffect(() => {
document.addEventListener("click", handleClick);
return () => document.removeEventListener("click", handleClick);
function handleClick(e) {
if (innerRef.current && callbackRef.current &&
!innerRef.current.contains(e.target)
) callbackRef.current(e);
}
}, []); // no dependencies -> stable click listener
return innerRef; // convenience for client (doesn't need to init ref himself)
}
Here is a working example:
/*
Custom Hook
*/
function useOuterClick(callback) {
const innerRef = useRef();
const callbackRef = useRef();
// set current callback in ref, before second useEffect uses it
useEffect(() => { // useEffect wrapper to be safe for concurrent mode
callbackRef.current = callback;
});
useEffect(() => {
document.addEventListener("click", handleClick);
return () => document.removeEventListener("click", handleClick);
// read most recent callback and innerRef dom node from refs
function handleClick(e) {
if (
innerRef.current &&
callbackRef.current &&
!innerRef.current.contains(e.target)
) {
callbackRef.current(e);
}
}
}, []); // no need for callback + innerRef dep
return innerRef; // return ref; client can omit `useRef`
}
/*
Usage
*/
const Client = () => {
const [counter, setCounter] = useState(0);
const innerRef = useOuterClick(e => {
// counter state is up-to-date, when handler is called
alert(`Clicked outside! Increment counter to ${counter + 1}`);
setCounter(c => c + 1);
});
return (
<div>
<p>Click outside!</p>
<div id="container" ref={innerRef}>
Inside, counter: {counter}
</div>
</div>
);
};
ReactDOM.render(<Client />, document.getElementById("root"));
#container { border: 1px solid red; padding: 20px; }
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.12.0/umd/react.production.min.js" integrity="sha256-Ef0vObdWpkMAnxp39TYSLVS/vVUokDE8CDFnx7tjY6U=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.12.0/umd/react-dom.production.min.js" integrity="sha256-p2yuFdE8hNZsQ31Qk+s8N+Me2fL5cc6NKXOC0U9uGww=" crossorigin="anonymous"></script>
<script> var {useRef, useEffect, useCallback, useState} = React</script>
<div id="root"></div>
Key points
useOuterClick makes use of mutable refs to provide lean Client API
stable click listener for lifetime of containing component ([] deps)
Client can set callback without needing to memoize it by useCallback
callback body has access to the most recent props and state - no stale closure values
(Side note for iOS)
iOS in general treats only certain elements as clickable. To make outer clicks work, choose a different click listener than document - nothing upwards including body. E.g. add a listener on the React root div and expand its height, like height: 100vh, to catch all outside clicks. Source: quirksmode.org
[Update] Solution with React ^16.8 using Hooks
CodeSandbox
import React, { useEffect, useRef, useState } from 'react';
const SampleComponent = () => {
const [clickedOutside, setClickedOutside] = useState(false);
const myRef = useRef();
const handleClickOutside = e => {
if (!myRef.current.contains(e.target)) {
setClickedOutside(true);
}
};
const handleClickInside = () => setClickedOutside(false);
useEffect(() => {
document.addEventListener('mousedown', handleClickOutside);
return () => document.removeEventListener('mousedown', handleClickOutside);
});
return (
<button ref={myRef} onClick={handleClickInside}>
{clickedOutside ? 'Bye!' : 'Hello!'}
</button>
);
};
export default SampleComponent;
Solution with React ^16.3:
CodeSandbox
import React, { Component } from "react";
class SampleComponent extends Component {
state = {
clickedOutside: false
};
componentDidMount() {
document.addEventListener("mousedown", this.handleClickOutside);
}
componentWillUnmount() {
document.removeEventListener("mousedown", this.handleClickOutside);
}
myRef = React.createRef();
handleClickOutside = e => {
if (!this.myRef.current.contains(e.target)) {
this.setState({ clickedOutside: true });
}
};
handleClickInside = () => this.setState({ clickedOutside: false });
render() {
return (
<button ref={this.myRef} onClick={this.handleClickInside}>
{this.state.clickedOutside ? "Bye!" : "Hello!"}
</button>
);
}
}
export default SampleComponent;
None of the other answers here worked for me. I was trying to hide a popup on blur, but since the contents were absolutely positioned, the onBlur was firing even on the click of inner contents too.
Here is an approach that did work for me:
// Inside the component:
onBlur(event) {
// currentTarget refers to this component.
// relatedTarget refers to the element where the user clicked (or focused) which
// triggered this event.
// So in effect, this condition checks if the user clicked outside the component.
if (!event.currentTarget.contains(event.relatedTarget)) {
// do your thing.
}
},
Hope this helps.
I found a solution thanks to Ben Alpert on discuss.reactjs.org. The suggested approach attaches a handler to the document but that turned out to be problematic. Clicking on one of the components in my tree resulted in a rerender which removed the clicked element on update. Because the rerender from React happens before the document body handler is called, the element was not detected as "inside" the tree.
The solution to this was to add the handler on the application root element.
main:
window.__myapp_container = document.getElementById('app')
React.render(<App/>, window.__myapp_container)
component:
import { Component, PropTypes } from 'react';
import ReactDOM from 'react-dom';
export default class ClickListener extends Component {
static propTypes = {
children: PropTypes.node.isRequired,
onClickOutside: PropTypes.func.isRequired
}
componentDidMount () {
window.__myapp_container.addEventListener('click', this.handleDocumentClick)
}
componentWillUnmount () {
window.__myapp_container.removeEventListener('click', this.handleDocumentClick)
}
/* using fat arrow to bind to instance */
handleDocumentClick = (evt) => {
const area = ReactDOM.findDOMNode(this.refs.area);
if (!area.contains(evt.target)) {
this.props.onClickOutside(evt)
}
}
render () {
return (
<div ref='area'>
{this.props.children}
</div>
)
}
}
MUI has a small component to solve this problem: https://mui.com/base/react-click-away-listener/ that you can cherry-pick it. It weights below 1 kB gzipped, it supports mobile, IE 11, and portals.
The Ez way... (UPDATED 2022)
Create a hook: useOutsideClick.ts
export function useOutsideClick(ref: any, onClickOut: () => void){
useEffect(() => {
const onClick = ({target}: any) => !ref.contains(target) && onClickOut?.()
document.addEventListener("click", onClick);
return () => document.removeEventListener("click", onClick);
}, []);
}
Add componentRef to your component and call useOutsideClick
export function Example(){
const componentRef = useRef();
useOutsideClick(componentRef.current!, () => {
// do something here
});
return (
<div ref={componentRef as any}> My Component </div>
)
}
Alternatively:
const onClickOutsideListener = () => {
alert("click outside")
document.removeEventListener("click", onClickOutsideListener)
}
...
return (
<div
onMouseLeave={() => {
document.addEventListener("click", onClickOutsideListener)
}}
>
...
</div>
with typescript
function Tooltip(): ReactElement {
const [show, setShow] = useState(false);
const ref = useRef<HTMLDivElement>(null);
useEffect(() => {
function handleClickOutside(event: MouseEvent): void {
if (ref.current && !ref.current.contains(event.target as Node)) {
setShow(false);
}
}
// Bind the event listener
document.addEventListener('mousedown', handleClickOutside);
return () => {
// Unbind the event listener on clean up
document.removeEventListener('mousedown', handleClickOutside);
};
});
return (
<div ref={ref}></div>
)
}
import { useClickAway } from "react-use";
useClickAway(ref, () => console.log('OUTSIDE CLICKED'));
For those who need absolute positioning, a simple option I opted for is to add a wrapper component that is styled to cover the whole page with a transparent background. Then you can add an onClick on this element to close your inside component.
<div style={{
position: 'fixed',
top: '0', right: '0', bottom: '0', left: '0',
zIndex: '1000',
}} onClick={() => handleOutsideClick()} >
<Content style={{position: 'absolute'}}/>
</div>
As it is right now if you add a click handler on content, the event will also be propagated to the upper div and therefore trigger the handlerOutsideClick. If this is not your desired behavior, simply stop the event progation on your handler.
<Content style={{position: 'absolute'}} onClick={e => {
e.stopPropagation();
desiredFunctionCall();
}}/>
`
Here is my approach (demo - https://jsfiddle.net/agymay93/4/):
I've created special component called WatchClickOutside and it can be used like (I assume JSX syntax):
<WatchClickOutside onClickOutside={this.handleClose}>
<SomeDropdownEtc>
</WatchClickOutside>
Here is code of WatchClickOutside component:
import React, { Component } from 'react';
export default class WatchClickOutside extends Component {
constructor(props) {
super(props);
this.handleClick = this.handleClick.bind(this);
}
componentWillMount() {
document.body.addEventListener('click', this.handleClick);
}
componentWillUnmount() {
// remember to remove all events to avoid memory leaks
document.body.removeEventListener('click', this.handleClick);
}
handleClick(event) {
const {container} = this.refs; // get container that we'll wait to be clicked outside
const {onClickOutside} = this.props; // get click outside callback
const {target} = event; // get direct click event target
// if there is no proper callback - no point of checking
if (typeof onClickOutside !== 'function') {
return;
}
// if target is container - container was not clicked outside
// if container contains clicked target - click was not outside of it
if (target !== container && !container.contains(target)) {
onClickOutside(event); // clicked outside - fire callback
}
}
render() {
return (
<div ref="container">
{this.props.children}
</div>
);
}
}
This already has many answers but they don't address e.stopPropagation() and preventing clicking on react links outside of the element you wish to close.
Due to the fact that React has it's own artificial event handler you aren't able to use document as the base for event listeners. You need to e.stopPropagation() before this as React uses document itself. If you use for example document.querySelector('body') instead. You are able to prevent the click from the React link. Following is an example of how I implement click outside and close.
This uses ES6 and React 16.3.
import React, { Component } from 'react';
class App extends Component {
constructor(props) {
super(props);
this.state = {
isOpen: false,
};
this.insideContainer = React.createRef();
}
componentWillMount() {
document.querySelector('body').addEventListener("click", this.handleClick, false);
}
componentWillUnmount() {
document.querySelector('body').removeEventListener("click", this.handleClick, false);
}
handleClick(e) {
/* Check that we've clicked outside of the container and that it is open */
if (!this.insideContainer.current.contains(e.target) && this.state.isOpen === true) {
e.preventDefault();
e.stopPropagation();
this.setState({
isOpen: false,
})
}
};
togggleOpenHandler(e) {
e.preventDefault();
this.setState({
isOpen: !this.state.isOpen,
})
}
render(){
return(
<div>
<span ref={this.insideContainer}>
<a href="#open-container" onClick={(e) => this.togggleOpenHandler(e)}>Open me</a>
</span>
<a href="/" onClick({/* clickHandler */})>
Will not trigger a click when inside is open.
</a>
</div>
);
}
}
export default App;
Typescript with Hooks
Note: I'm using React version 16.3, with React.createRef. For other versions use the ref callback.
Dropdown component:
interface DropdownProps {
...
};
export const Dropdown: React.FC<DropdownProps> () {
const ref: React.RefObject<HTMLDivElement> = React.createRef();
const handleClickOutside = (event: MouseEvent) => {
if (ref && ref !== null) {
const cur = ref.current;
if (cur && !cur.contains(event.target as Node)) {
// close all dropdowns
}
}
}
useEffect(() => {
// Bind the event listener
document.addEventListener("mousedown", handleClickOutside);
return () => {
// Unbind the event listener on clean up
document.removeEventListener("mousedown", handleClickOutside);
};
});
return (
<div ref={ref}>
...
</div>
);
}
I did this partly by following this and by following the React official docs on handling refs which requires react ^16.3. This is the only thing that worked for me after trying some of the other suggestions here...
class App extends Component {
constructor(props) {
super(props);
this.inputRef = React.createRef();
}
componentWillMount() {
document.addEventListener("mousedown", this.handleClick, false);
}
componentWillUnmount() {
document.removeEventListener("mousedown", this.handleClick, false);
}
handleClick = e => {
/*Validating click is made inside a component*/
if ( this.inputRef.current === e.target ) {
return;
}
this.handleclickOutside();
};
handleClickOutside(){
/*code to handle what to do when clicked outside*/
}
render(){
return(
<div>
<span ref={this.inputRef} />
</div>
)
}
}
Simply with ClickAwayListener from mui (material-ui):
<ClickAwayListener onClickAway={handleClickAway}>
{children}
<ClickAwayListener >
for more info you can check:https://mui.com/base/react-click-away-listener/
To extend on the accepted answer made by Ben Bud, if you are using styled-components, passing refs that way will give you an error such as "this.wrapperRef.contains is not a function".
The suggested fix, in the comments, to wrap the styled component with a div and pass the ref there, works.
Having said that, in their docs they already explain the reason for this and the proper use of refs within styled-components:
Passing a ref prop to a styled component will give you an instance of the StyledComponent wrapper, but not to the underlying DOM node. This is due to how refs work. It's not possible to call DOM methods, like focus, on our wrappers directly.
To get a ref to the actual, wrapped DOM node, pass the callback to the innerRef prop instead.
Like so:
<StyledDiv innerRef={el => { this.el = el }} />
Then you can access it directly within the "handleClickOutside" function:
handleClickOutside = e => {
if (this.el && !this.el.contains(e.target)) {
console.log('clicked outside')
}
}
This also applies for the "onBlur" approach:
componentDidMount(){
this.el.focus()
}
blurHandler = () => {
console.log('clicked outside')
}
render(){
return(
<StyledDiv
onBlur={this.blurHandler}
tabIndex="0"
innerRef={el => { this.el = el }}
/>
)
}
This is my way of solving the problem
I return a boolean value from my custom hook, and when this value changes (true if the click was outside of the ref that I passed as an arg), this way i can catch this change with an useEffect hook, i hope it's clear for you.
Here's a live example:
Live Example on codesandbox
import { useEffect, useRef, useState } from "react";
const useOutsideClick = (ref) => {
const [outsieClick, setOutsideClick] = useState(null);
useEffect(() => {
const handleClickOutside = (e) => {
if (!ref.current.contains(e.target)) {
setOutsideClick(true);
} else {
setOutsideClick(false);
}
setOutsideClick(null);
};
document.addEventListener("mousedown", handleClickOutside);
return () => {
document.removeEventListener("mousedown", handleClickOutside);
};
}, [ref]);
return outsieClick;
};
export const App = () => {
const buttonRef = useRef(null);
const buttonClickedOutside = useOutsideClick(buttonRef);
useEffect(() => {
// if the the click was outside of the button
// do whatever you want
if (buttonClickedOutside) {
alert("hey you clicked outside of the button");
}
}, [buttonClickedOutside]);
return (
<div className="App">
<button ref={buttonRef}>click outside me</button>
</div>
);
}
Typescript + simplified version of #ford04's proposal:
useOuterClick API
const Client = () => {
const ref = useOuterClick<HTMLDivElement>(e => { /* Custom-event-handler */ });
return <div ref={ref}> Inside </div>
};
Implementation
export default function useOuterClick<T extends HTMLElement>(callback: Function) {
const callbackRef = useRef<Function>(); // initialize mutable ref, which stores callback
const innerRef = useRef<T>(null); // returned to client, who marks "border" element
// update cb on each render, so second useEffect has access to current value
useEffect(() => { callbackRef.current = callback; });
useEffect(() => {
document.addEventListener("click", _onClick);
return () => document.removeEventListener("click", _onClick);
function _onClick(e: any): void {
const clickedOutside = !(innerRef.current?.contains(e.target));
if (clickedOutside)
callbackRef.current?.(e);
}
}, []); // no dependencies -> stable click listener
return innerRef; // convenience for client (doesn't need to init ref himself)
}
So I faced a similar problem but in my case the selected answer here wasn't working because I had a button for the dropdown which is, well, a part of the document. So clicking the button also triggered the handleClickOutside function. To stop that from triggering, I had to add a new ref to the button and this !menuBtnRef.current.contains(e.target) to the conditional. I'm leaving it here if someone is facing the same issue like me.
Here's how the component looks like now:
const Component = () => {
const [isDropdownOpen, setIsDropdownOpen] = useState(false);
const menuRef = useRef(null);
const menuBtnRef = useRef(null);
const handleDropdown = (e) => {
setIsDropdownOpen(!isDropdownOpen);
}
const handleClickOutside = (e) => {
if (menuRef.current && !menuRef.current.contains(e.target) && !menuBtnRef.current.contains(e.target)) {
setIsDropdownOpen(false);
}
}
useEffect(() => {
document.addEventListener('mousedown', handleClickOutside, true);
return () => {
document.removeEventListener('mousedown', handleClickOutside, true);
};
}, []);
return (
<button ref={menuBtnRef} onClick={handleDropdown}></button>
<div ref={menuRef} className={`${isDropdownOpen ? styles.dropdownMenuOpen : ''}`}>
// ...dropdown items
</div>
)
}
My biggest concern with all of the other answers is having to filter click events from the root/parent down. I found the easiest way was to simply set a sibling element with position: fixed, a z-index 1 behind the dropdown and handle the click event on the fixed element inside the same component. Keeps everything centralized to a given component.
Example code
#HTML
<div className="parent">
<div className={`dropdown ${this.state.open ? open : ''}`}>
...content
</div>
<div className="outer-handler" onClick={() => this.setState({open: false})}>
</div>
</div>
#SASS
.dropdown {
display: none;
position: absolute;
top: 0px;
left: 0px;
z-index: 100;
&.open {
display: block;
}
}
.outer-handler {
position: fixed;
top: 0;
left: 0;
right: 0;
bottom: 0;
opacity: 0;
z-index: 99;
display: none;
&.open {
display: block;
}
}
componentWillMount(){
document.addEventListener('mousedown', this.handleClickOutside)
}
handleClickOutside(event) {
if(event.path[0].id !== 'your-button'){
this.setState({showWhatever: false})
}
}
Event path[0] is the last item clicked
I used this module (I have no association with the author)
npm install react-onclickout --save
const ClickOutHandler = require('react-onclickout');
class ExampleComponent extends React.Component {
onClickOut(e) {
if (hasClass(e.target, 'ignore-me')) return;
alert('user clicked outside of the component!');
}
render() {
return (
<ClickOutHandler onClickOut={this.onClickOut}>
<div>Click outside of me!</div>
</ClickOutHandler>
);
}
}
It did the job nicely.
UseOnClickOutside Hook - React 16.8 +
Create a general useOnOutsideClick function
export const useOnOutsideClick = handleOutsideClick => {
const innerBorderRef = useRef();
const onClick = event => {
if (
innerBorderRef.current &&
!innerBorderRef.current.contains(event.target)
) {
handleOutsideClick();
}
};
useMountEffect(() => {
document.addEventListener("click", onClick, true);
return () => {
document.removeEventListener("click", onClick, true);
};
});
return { innerBorderRef };
};
const useMountEffect = fun => useEffect(fun, []);
Then use the hook in any functional component.
const OutsideClickDemo = ({ currentMode, changeContactAppMode }) => {
const [open, setOpen] = useState(false);
const { innerBorderRef } = useOnOutsideClick(() => setOpen(false));
return (
<div>
<button onClick={() => setOpen(true)}>open</button>
{open && (
<div ref={innerBorderRef}>
<SomeChild/>
</div>
)}
</div>
);
};
Link to demo
Partially inspired by #pau1fitzgerald answer.
In my DROPDOWN case the Ben Bud's solution worked well, but I had a separate toggle button with an onClick handler. So the outside clicking logic conflicted with the button onClick toggler. Here is how I solved it by passing the button's ref as well:
import React, { useRef, useEffect, useState } from "react";
/**
* Hook that triggers onClose when clicked outside of ref and buttonRef elements
*/
function useOutsideClicker(ref, buttonRef, onOutsideClick) {
useEffect(() => {
function handleClickOutside(event) {
/* clicked on the element itself */
if (ref.current && !ref.current.contains(event.target)) {
return;
}
/* clicked on the toggle button */
if (buttonRef.current && !buttonRef.current.contains(event.target)) {
return;
}
/* If it's something else, trigger onClose */
onOutsideClick();
}
// Bind the event listener
document.addEventListener("mousedown", handleClickOutside);
return () => {
// Unbind the event listener on clean up
document.removeEventListener("mousedown", handleClickOutside);
};
}, [ref]);
}
/**
* Component that alerts if you click outside of it
*/
export default function DropdownMenu(props) {
const wrapperRef = useRef(null);
const buttonRef = useRef(null);
const [dropdownVisible, setDropdownVisible] = useState(false);
useOutsideClicker(wrapperRef, buttonRef, closeDropdown);
const toggleDropdown = () => setDropdownVisible(visible => !visible);
const closeDropdown = () => setDropdownVisible(false);
return (
<div>
<button onClick={toggleDropdown} ref={buttonRef}>Dropdown Toggler</button>
{dropdownVisible && <div ref={wrapperRef}>{props.children}</div>}
</div>
);
}
I had a similar use case where I had to develop a custom dropdown menu. it should close automatically when the user clicks outside. here is the recent React Hooks implementation-
import { useEffect, useRef, useState } from "react";
export const App = () => {
const ref = useRef();
const [isMenuOpen, setIsMenuOpen] = useState(false);
useEffect(() => {
const checkIfClickedOutside = (e) => {
// If the menu is open and the clicked target is not within the menu,
// then close the menu
if (isMenuOpen && ref.current && !ref.current.contains(e.target)) {
setIsMenuOpen(false);
}
};
document.addEventListener("mousedown", checkIfClickedOutside);
return () => {
// Cleanup the event listener
document.removeEventListener("mousedown", checkIfClickedOutside);
};
}, [isMenuOpen]);
return (
<div className="wrapper" ref={ref}>
<button
className="button"
onClick={() => setIsMenuOpen((oldState) => !oldState)}
>
Click Me
</button>
{isMenuOpen && (
<ul className="list">
<li className="list-item">dropdown option 1</li>
<li className="list-item">dropdown option 2</li>
<li className="list-item">dropdown option 3</li>
<li className="list-item">dropdown option 4</li>
</ul>
)}
</div>
);
}
An example with Strategy
I like the provided solutions that use to do the same thing by creating a wrapper around the component.
Since this is more of a behavior I thought of Strategy and came up with the following.
I'm new with React and I need a bit of help in order to save some boilerplate in the use cases
Please review and tell me what you think.
ClickOutsideBehavior
import ReactDOM from 'react-dom';
export default class ClickOutsideBehavior {
constructor({component, appContainer, onClickOutside}) {
// Can I extend the passed component's lifecycle events from here?
this.component = component;
this.appContainer = appContainer;
this.onClickOutside = onClickOutside;
}
enable() {
this.appContainer.addEventListener('click', this.handleDocumentClick);
}
disable() {
this.appContainer.removeEventListener('click', this.handleDocumentClick);
}
handleDocumentClick = (event) => {
const area = ReactDOM.findDOMNode(this.component);
if (!area.contains(event.target)) {
this.onClickOutside(event)
}
}
}
Sample Usage
import React, {Component} from 'react';
import {APP_CONTAINER} from '../const';
import ClickOutsideBehavior from '../ClickOutsideBehavior';
export default class AddCardControl extends Component {
constructor() {
super();
this.state = {
toggledOn: false,
text: ''
};
this.clickOutsideStrategy = new ClickOutsideBehavior({
component: this,
appContainer: APP_CONTAINER,
onClickOutside: () => this.toggleState(false)
});
}
componentDidMount () {
this.setState({toggledOn: !!this.props.toggledOn});
this.clickOutsideStrategy.enable();
}
componentWillUnmount () {
this.clickOutsideStrategy.disable();
}
toggleState(isOn) {
this.setState({toggledOn: isOn});
}
render() {...}
}
Notes
I thought of storing the passed component lifecycle hooks and override them with methods simillar to this:
const baseDidMount = component.componentDidMount;
component.componentDidMount = () => {
this.enable();
baseDidMount.call(component)
}
component is the component passed to the constructor of ClickOutsideBehavior.
This will remove the enable/disable boilerplate from the user of this behavior but it doesn't look very nice though

Client device width get undefined after page load it show.How to get client device width before page load in the Nextjs

Here is a code for getting width..
pages/_app.js
import { useWindowDimensions } from "../helper/useWindowDimensions";
function MyApp({ Component, pageProps, globalQuotesData }) {
const { width } = useWindowDimensions();
}
Helper/useWindowDimensions.js
import { useEffect, useState } from 'react';
export function useWindowDimensions () {
const [windowDimensions, setWindowDimensions] = useState({
width: '',
height: '',
});
useEffect(() => {
function handleResize() {
setWindowDimensions({
width: window.innerWidth,
height: window.innerHeight,
});
}
handleResize();
window.addEventListener('resize', handleResize);
return () => window.removeEventListener('resize', handleResize);
}, []); // Empty array ensures that effect is only run on mount
return windowDimensions;
};
when page load at that time width get undefined or blank after sometime when whole page get load then it shows current device width.how can i get width before page load.

disable scrolling on specific page

Is there any way to disable scroll on one single page? I tried to set overflow: hidden on the specific page but that didn't work. I have to set it on the body in index.css to make it work but that obviously disable scroll on all pages. So the only way to do it that comes to my mind is to set CSS class conditionally on the body. Is there any way to conditionally set CSS class in index.js based on the value from a redux store or is there any other way?
my index.js
import React from 'react';
import ReactDOM from 'react-dom';
import {BrowserRouter} from 'react-router-dom'
import {Provider} from 'react-redux'
import {createStore,applyMiddleware,compose,combineReducers} from "redux";
import thunk from 'redux-thunk'
import './index.css';
import App from './App';
import * as serviceWorker from './serviceWorker';
import authReducer from './store/reducers/auth'
const composeEnhancers = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;
const rootReducer = combineReducers({
auth: authReducer
})
const store = createStore(rootReducer,
composeEnhancers(applyMiddleware(thunk)));
const app =(
<Provider store={store}>
<BrowserRouter>
<App/>
</BrowserRouter>
</Provider>
)
ReactDOM.render(
<React.StrictMode>
{app}
</React.StrictMode>,
document.getElementById('root')
);
serviceWorker.unregister();
If you wanted to set a style on body, you can just run the below code on the page, which will disable scrolling.
document.body.style.overflow='hidden'
Then to re-enable:
document.body.style.overflow='auto'
Only downside is that is isn't very React-like.
Simple solution might be to define specific class to apply overflow: hidden and apply it on document.body whenever you want (for example after explicit component mount).
.overflow-hidden {
overflow: hidden;
}
On mount of specific page call:
document.body.classList.add("overflow-hidden");
or you can directly assign property
document.body.style.overflow = "hidden";
You can wrap your component in another div, and give that wrapper div the overflow:hidden; style, possibly along with a max-height: 70vh; to make sure it doesn't go over the end of the page.
div {
padding: .5rem;
margin: .5rem
}
.no-scroll-wrapper {
max-height: 70vh;
overflow: hidden;
background-color: darkgrey;
padding: 1rem;
}
.large-inner {
height: 1000px;
background-color: grey
}
<body>
<div class="no-scroll-wrapper">
wrapper element disables scrolling
<div class="large-inner">
Content here, very long div, but you can't see the end of it.
</div>
</div>
</body
A simple solution might be to define a specific class to apply overflow: hidden and apply it on the document. body whenever you want and remove the class when you leave the page.
.overflow-hidden {
overflow: hidden;
}
Attach class on the body in the specific page and remove when you live the page, so it won't affect other pages
useEffect(() => {
document.body.classList.add("overflow-hidden");
return () => {
document.body.classList.remove("overflow-hidden");
};
}, []);
This will simply remove the class from the body when you leave the page.
Adding to Luke Storry's and midnightgamer's amazing answer. You can use a custom react hook with useEffect instead of having to add document.body.style.overflow='auto' in every page to re-enable scroll.
import { useEffect } from 'react'
const useOverFlowHidden = () => {
useEffect(() => {
document.body.style.overflow = 'hidden'
return () => {
document.body.style.overflow = 'auto' // cleanup or run on page unmount
}
}, [])
}
export default useOverFlowHidden
Usage:
const Page = () => {
useOverFlowHidden(); // use on pages you want to disable overflow/scroll
return <></>;
}
I use body-scroll-lock npm package:
import {disableBodyScroll,enableBodyScroll,clearAllBodyScrollLocks} from "body-scroll-lock"
const YourPage=(props)=>{
const ref=useRef(null)
useEffect(() => {
if (ref.current) {
// you might add a condition to lock the scroll
if (conditionIsTrue) {
disableBodyScroll(ref.current)
} else {
enableBodyScroll(ref.current)
}
}
return () => {
clearAllBodyScrollLocks()
}
},[addDependencyHere])
return(
<div ref={ref}>
....
</>
)
}
from the above npm package's documentation, you can also use this approach with vanilla js. It is not recommended to access document object in react.js directly
document.body.ontouchmove = (e) => {
e.preventDefault();
return false;
on touch screen devices you can set this css class conditionally to prevent scrolling
touch-action:none

Detect child div size changed

I have what I like to call "Accordion Inception". My initial accordion will measure its children and set a max-height on the accordionContent. This CSS property is necessary to keep when using CSS Transitions on Auto Dimensions
However, if part of the content is another accordion. I'm not able to detect the child has opened up and need to remeasure and set a new max-height on the parent accordion.
Here is a demo
export const AccordionBody = ({ children }) => {
const { isCollapsed } = useContext(AccordionContext);
const [bodyCallback, scrollHeight] = useScrollHeightByRef();
return (
<div
ref={bodyCallback}
id="accordion-body"
css={accordionBody(isCollapsed, scrollHeight)}
>
<div css={accordionContent}> //I need to somehow measure this when it's contents change
{children}
</div>
</div>
)
}
Here is the hook I'm using to measure the bodyHeight
import { useState, useCallback } from "react";
export function useScrollHeightByRef() {
const [scrollHeight, setScrollHeight] = useState();
const ref = useCallback(
el => {
if (el) {
setScrollHeight(el.scrollHeight);
}
},
[setScrollHeight]
);
return [ref, scrollHeight];
}
I could possibly pass an onChange function into each child but that seems pretty cumbersome. I'm looking for something to detect when the child changes.

Resources