How can I change state in client-side in NEXT.js? - next.js

I have a simple tab component in NEXT. Here's my component code:
const Tabs = ({ tabItems }) => {
const setActiveTab = (tabItem) => {
for (var i = 0; i < tabItems.length; i++) {
tabItems[i].active = false;
}
tabItem.active = true;
}
return <div>
{
tabItems.map(tabItem => <div
className={tabItem.active ? "active-tab" : ""}
onClick={() => setActiveTab(tabItem)}
>{tabItem.title}</div>)
}
</div>
}
However, when I click on tab items, the state does not change.
How can I change state in client-side in NEXT?

You can't change state from a parent like this. The way that you're doing, you're only changing the value of tabItem inside the children component.
You could use Context API to achieve the desired result, or just pass down a function from the parent, which would be the best if you're not passing props down too many components.
Code example:
parent.tsx:
export const Parent = () => {
const [tabItems, setTabItems] = useState()
function changeTabItems(newValue) {
setTabItems(newValue)
}
return <Child changeTabItems={changeTabItems} tabItems={tabItems}/>
}
child.tsx:
export const Child = ({changeTabItems, tabItems}) => {
function setActiveTab(tabItem) {
let aux = tabItems
for (var i = 0; i < tabItems.length; i++) {
aux[i].active = false;
}
aux.active = true;
changeTabItems({...aux})
}
}

Related

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

Change background-color once scrolled with react?

I want to change the bg color of my navbar div once I scroll down. And if it's already at the top, I want to revert back to the original. I tried doing this following some code I got from a website.
I am using tailwind for CSS and React.
Is there a better way to do this? And is there some kind of fault with this code?
export default function Home(props) {
const [scrollPosition, setScrollPosition] = useState(0);
const [top, setTop] = useState(true)
const handleScroll = () => {
const position = window.scrollY;
setScrollPosition(position);
if (scrollPosition == 0) {
setTop(true)
} else if (scrollPosition > 10) {
setTop(false)
} else if (scrollPosition < 10) {
setTop(true)
}
}
useEffect(() => {
window.addEventListener('scroll', handleScroll)
return () => {
window.removeEventListener('scroll', handleScroll)
}
})
return (
<div className={`${top ? 'bg-blue-500' : "bg-red-500"}`}>
</div>
);
}

I want to remove a className after a few seconds, or re trigger the class animation when condition is met

Goal: When there is a price change,i want the price number to higlight for a few seconds with a color. I do that with the toogleClassName.
Problem: When the iteration is UP UP,or DOWN DOWN,the element already has that class and the CSS animation already ran.
JSX Code:
import React, { useEffect, useState, useRef } from "react";
import styles from "./CoinContainer.module.css";
function usePrevious(data) {
const ref = useRef();
useEffect(() => {
ref.current = data;
}, [data]);
return ref.current;
}
export default function CoinContainer({ coin, price }) {
const [priceUpdated, setPrice] = useState("");
const prevPrice = usePrevious(priceUpdated);
// Update price
useEffect(() => {
setInterval(priceUpdate, 20000);
}, []);
// Apply different flash-color style according to up$ or down$ from prev
const toggleClassName = () => {
return prevPrice > priceUpdated ? styles.redPrice : styles.greenPrice;
};
function priceUpdate() {
return fetch(
`https://api.coingecko.com/api/v3/simple/price?ids=${coin}&vs_currencies=usd`
)
.then((data) => data.json())
.then((result) => {
let key = Object.keys(result);
setPrice(result[key].usd);
});
}
return (
<div className={styles.padding}>
<h2>{coin}</h2>
{/* Here is the problem,i would like to remove the class after a few seconds,or edit the CSS code to retrigger the animation */}
<h3 className={toggleClassName()}>
{priceUpdated ? priceUpdated : price}$
</h3>
</div>
);
}
CSS Code
#keyframes upFadeBetween {
from {
color: green;
}
to {
color: white;
}
}
#keyframes downFadeBetween {
from {
color: red;
}
to {
color: white;
}
}
.redPrice {
animation: downFadeBetween 5s;
color: white;
}
.greenPrice {
animation: upFadeBetween 5s;
color: white;
}
Thanks so much for any feedback/help!
You could use another variable called e.g. reset
const [reset, setReset] = useState(false);
And then set this value at your methods using setTimeout
const toggleClassName = () => {
setTimeout(() => setReset(true), 6000);
return prevPrice > priceUpdated ? styles.redPrice : styles.greenPrice;
};
function priceUpdate() {
return fetch(
`https://api.coingecko.com/api/v3/simple/price?ids=${coin}&vs_currencies=usd`
)
.then((data) => data.json())
.then((result) => {
let key = Object.keys(result);
setReset(false);
setPrice(result[key].usd);
});
}
and finally
<h3 className={reset ? "" : toggleClassName()}>
you can do this
handleClick = event => event.target.classList.add('click-state');
or as react is js library so definitly it will support js DOM elements, well there is no doubt that it uses DOM also.
so you can do this also,
for adding class
document.getElementById("id here").classList.add("classname here");
for removing class
document.getElementById("id here").classList.remove("classname here");
OR
you can also use react States
You can use a variable that will be updated every time you trigger the fetch.
In this case, we will call it animationStyle
function CoinContainer({ coin, price }) {
const [priceUpdated, setPrice] = useState("")
const [animationStyle, setAnimationStyle] = useState("")
useEffect(() => {
setInterval(priceUpdate, 20000)
}, [])
function updateAnimationStyle(){
if (prevPrice > priceUpdated) {
setAnimationStyle("redPrice")
} else {
setAnimationStyle("greenPrice")
}
setTimeout(() => {
setAnimation("")
}, 5000)
}
function priceUpdate() {
return fetch(
`https://api.coingecko.com/api/v3/simple/price?ids=${coin}&vs_currencies=usd`
)
.then((data) => data.json())
.then((result) => {
let key = Object.keys(result)
setPrice(result[key].usd)
updateAnimationStyle()
})
}
return (
<div className={styles.padding}>
<h2>{coin}</h2>
<h3 className={animationStyle}>//you avoid doing the conditional rendering that might be a bit confusing
{priceUpdated ? priceUpdated : price}$
</h3>
</div>
)
}
Okay, so basically, the approach is to avoid too large conditional rendering inside the jsx.
the function updateAnimationStyle gets called every time the fetch is triggered.
depending on the condition, updateAnimationStyle will set redPrice or greenPrice animations to animationStyle.
the animationStyle will clean after 5 seconds through setTimeout function. "it can not be less than 5s because you have set the animation duration to 5s".
const [priceUpdated, setPrice] = useState("") it is better to avoid this type of naming for variables.
Instead, if you use const [priceUpdated, setPriceUpdated] = useState(""), it will be more readable.
Hope it works for you!
Regards.

How to optimise react typography component?

I have code:
const H1 = ({style, children}) => {
return <h1 className={styleMap[style]}>{children}</h1>
}
const H2 = ({style, children}) => {
return <h2 className={styleMap[style]}>{children}</h2>
}
My goal is to reduce repeated code, so that I will have something like:
const H{number} = ({style, children}) => {
return <h{number} className={styleMap[style]}>{children}</h{number}>
}
But I would be able to call it like
<H1 style='style5'>Main Title</H1>
<H2 style='style2'>Subtitle</H2>
const H{number} = ({style, children}) => {
return <h{number} className={styleMap[style]}>{children}</h{number}>
}
This syntax you want is not possible. But you can dynamically decide which header level you wanna you by passing in a prop.
function Header(props) {
const { level, style, children } = props
if (Number.isInteger(level) && level >= 1 && level <= 6) {
return React.createElement(`h${level}`, { className: styleMap[style] }, children)
} else {
throw Error('Invalid "level" prop, must be number 1-6')
}
}
// Usage:
<Header level={1} style='style5'>Main Title</Header>
You have to resort to the plain JS React.createElement syntax, cus JSX doesn't allow you to use dynamic value for component, it's simply syntax error to write <{whatever} /> in JSX.

Dispatching actions in Redux while using Apollo Client causes Apollo client to reset query

I have a Component that is a TypeAhead. When the user enters the component page Apollo pulls an initial query of 5 players that is used for the typeahead. Ideally i would like to skip this initial query but thats another thing entirely. So the query is filled with 5 players. Player1 to Player5, When i start typing in the typeahead searching for Player10, I select Player10 and it dispatches an action to make it the currently selected Player. However after I trigger an onBlur or leave the box, Apollo dispatches a Redux action of APOLLO_QUERY_RESULT_CLIENT which sets all the typeAhead back to Player1 to Player5 my initial query instead of having it set correctly to Player10. How do you prevent that APOLLO_QUERY_RESULT_CLIENT from dispatching as it dispatches anytime i dispatch an action that i created myself.
class TypeAhead extends Component {
constructor() {
super();
this.state = {
value: ''
};
}
renderInputComponent = (inputProps) => {
let {selectedSuggestion} = this.props;
return (
<div className="inputContainer">
<img className="type-ahead__image" alt="" src={getImageURL(selectedSuggestion.id)} />
<TextField floatingLabelText="Search Player" {...inputProps} />
</div>
)
}
onChange = (event, { newValue }) => {
this.setState({
value: newValue
});
};
shouldRenderSuggestions(value) {
return value.trim().length > MIN_SEARCH_LENGTH;
}
onSuggestionsFetchRequested = ({ value }) => {
// debugger;
if(/^[a-z .,-]+$/i.test(value)) {
this.props.data.refetch({name: value});
}
};
onSuggestionsClearRequested = () => {
// debugger;
// this.setState({
// suggestions: []
// });
// this.props.data.Players = [];
};
onBlur = () => {
if (this.state.value.toLowerCase() === this.props.data.Players[0].name.toLowerCase()) {
let suggestion = this.props.data.Players[0];
this.props.onSuggestionSelected(null, { suggestion });
}
}
render() {
console.log(this.props.data.Players)
let suggestions = this.props.data.Players || [];
let { onSuggestionSelected } = this.props;
let { value } = this.state;
let inputProps = {
value,
onChange: this.onChange,
onBlur: this.onBlur
};
return (
<div>
<Autosuggest
suggestions={suggestions}
onSuggestionsFetchRequested={this.onSuggestionsFetchRequested}
onSuggestionsClearRequested={this.onSuggestionsClearRequested}
getSuggestionValue={getSuggestionValue}
renderSuggestion={renderSuggestion}
shouldRenderSuggestions={this.shouldRenderSuggestions}
onSuggestionSelected={onSuggestionSelected}
renderInputComponent={this.renderInputComponent}
inputProps={inputProps}
/>
</div>
);
}
}
const mapStateToProps = (state) => {
return {
selectedSuggestion: state.selectedSuggestion
}
}
const mapDispatchToProps = (dispatch) => {
return {
onSuggestionSelected(event, {suggestion}) {
dispatch(actions.selectSuggestion(suggestion));
// dispatching action causes apollo to requery and pull inital query causing issues.
},
onSuggestionUnselected() {
dispatch(actions.unselectSuggestion());
}
}
}
const TypeAheadWithData = graphql(TypeAheadQuery, {
options: ({ name }) => ({ variables: { name } })
})(TypeAhead);
const TypeAheadWithDataAndState = connect(mapStateToProps, mapDispatchToProps)(TypeAheadWithData);
export default TypeAheadWithDataAndState;
const TypeAheadWithData = graphql(TypeAheadQuery, {
options: ({ name }) => ({ variables: { name } })
})(TypeAhead);
Whenever the name prop changes, the query will be run again. It is very likely that you reset the name just before the query is run again.
If this is not the case, you can know why the graphql container is refetching by debugging the networkStatus. You also need to add options: { notifyOnNetworkStatusChange: true }

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