React Native: Different styles applied on orientation change - css
I'm developing a React Native application to be deployed as a native application on iOS and Android (and Windows, if possible).
The problem is that we want the layout to be different depending on screen dimensions and its orientation.
I've made some functions that return the styles object and are called on every component render's function, so I am able to apply different styles at application startup, but if the orientation (or screen's size) changes once the app has been initialized, they aren't recalculated nor reapplied.
I've added listeners to the top rendered so it updates its state on orientation change (and it forces a render for the rest of the application), but the subcomponents are not rerendering (because, in fact, they have not been changed).
So, my question is: how can I make to have styles that may be completely different based on screen size and orientation, just as with CSS Media Queries (which are rendered on the fly)?
I've already tried react-native-responsive module without luck.
Thank you!
If using Hooks. You can refer to this solution: https://stackoverflow.com/a/61838183/5648340
The orientation of apps from portrait to landscape and vice versa is a task that sounds easy but may be tricky in react native when the view has to be changed when orientation changes. In other words, having different views defined for the two orientations can be achieved by considering these two steps.
Import Dimensions from React Native
import { Dimensions } from 'react-native';
To identify the current orientation and render the view accordingly
/**
* Returns true if the screen is in portrait mode
*/
const isPortrait = () => {
const dim = Dimensions.get('screen');
return dim.height >= dim.width;
};
/**
* Returns true of the screen is in landscape mode
*/
const isLandscape = () => {
const dim = Dimensions.get('screen');
return dim.width >= dim.height;
};
To know when orientation changes to change view accordingly
// Event Listener for orientation changes
Dimensions.addEventListener('change', () => {
this.setState({
orientation: Platform.isPortrait() ? 'portrait' : 'landscape'
});
});
Assembling all pieces
import React from 'react';
import {
StyleSheet,
Text,
Dimensions,
View
} from 'react-native';
export default class App extends React.Component {
constructor() {
super();
/**
* Returns true if the screen is in portrait mode
*/
const isPortrait = () => {
const dim = Dimensions.get('screen');
return dim.height >= dim.width;
};
this.state = {
orientation: isPortrait() ? 'portrait' : 'landscape'
};
// Event Listener for orientation changes
Dimensions.addEventListener('change', () => {
this.setState({
orientation: isPortrait() ? 'portrait' : 'landscape'
});
});
}
render() {
if (this.state.orientation === 'portrait') {
return (
//Render View to be displayed in portrait mode
);
}
else {
return (
//Render View to be displayed in landscape mode
);
}
}
}
As the event defined for looking out the orientation change uses this command ‘this.setState()’, this method automatically again calls for ‘render()’ so we don’t have to worry about rendering it again, it’s all taken care of.
Here's #Mridul Tripathi's answer as a reusable hook:
// useOrientation.tsx
import {useEffect, useState} from 'react';
import {Dimensions} from 'react-native';
/**
* Returns true if the screen is in portrait mode
*/
const isPortrait = () => {
const dim = Dimensions.get('screen');
return dim.height >= dim.width;
};
/**
* A React Hook which updates when the orientation changes
* #returns whether the user is in 'PORTRAIT' or 'LANDSCAPE'
*/
export function useOrientation(): 'PORTRAIT' | 'LANDSCAPE' {
// State to hold the connection status
const [orientation, setOrientation] = useState<'PORTRAIT' | 'LANDSCAPE'>(
isPortrait() ? 'PORTRAIT' : 'LANDSCAPE',
);
useEffect(() => {
const callback = () => setOrientation(isPortrait() ? 'PORTRAIT' : 'LANDSCAPE');
Dimensions.addEventListener('change', callback);
return () => {
Dimensions.removeEventListener('change', callback);
};
}, []);
return orientation;
}
You can then consume it using:
import {useOrientation} from './useOrientation';
export const MyScreen = () => {
const orientation = useOrientation();
return (
<View style={{color: orientation === 'PORTRAIT' ? 'red' : 'blue'}} />
);
}
You can use the onLayout prop:
export default class Test extends Component {
constructor(props) {
super(props);
this.state = {
screen: Dimensions.get('window'),
};
}
getOrientation(){
if (this.state.screen.width > this.state.screen.height) {
return 'LANDSCAPE';
}else {
return 'PORTRAIT';
}
}
getStyle(){
if (this.getOrientation() === 'LANDSCAPE') {
return landscapeStyles;
} else {
return portraitStyles;
}
}
onLayout(){
this.setState({screen: Dimensions.get('window')});
}
render() {
return (
<View style={this.getStyle().container} onLayout = {this.onLayout.bind(this)}>
</View>
);
}
}
}
const portraitStyles = StyleSheet.create({
...
});
const landscapeStyles = StyleSheet.create({
...
});
Finally, I've been able to do so. Don't know the performance issues it can carry, but they should not be a problem since it's only called on resizing or orientation change.
I've made a global controller where I have a function which receives the component (the container, the view) and adds an event listener to it:
const getScreenInfo = () => {
const dim = Dimensions.get('window');
return dim;
}
const bindScreenDimensionsUpdate = (component) => {
Dimensions.addEventListener('change', () => {
try{
component.setState({
orientation: isPortrait() ? 'portrait' : 'landscape',
screenWidth: getScreenInfo().width,
screenHeight: getScreenInfo().height
});
}catch(e){
// Fail silently
}
});
}
With this, I force to rerender the component when there's a change on orientation, or on window resizing.
Then, on every component constructor:
import ScreenMetrics from './globalFunctionContainer';
export default class UserList extends Component {
constructor(props){
super(props);
this.state = {};
ScreenMetrics.bindScreenDimensionsUpdate(this);
}
}
This way, it gets rerendered everytime there's a window resize or an orientation change.
You should note, however, that this must be applied to every component which we want to listen to orientation changes, since if the parent container is updated but the state (or props) of the children do not update, they won't be rerendered, so it can be a performance kill if we have a big children tree listening to it.
Hope it helps someone!
I made a super light component that addresses this issue.
https://www.npmjs.com/package/rn-orientation-view
The component re-renders it's content upon orientation change.
You can, for example, pass landscapeStyles and portraitStyles to display these orientations differently.
Works on iOS and Android.
It's easy to use. Check it out.
React Native also have useWindowDimensions hooks that returns the width and height of your device.
With this, you can check easily if the device is in 'Portrait' or 'Landscape' by comparing the width and height.
See more here
I had the same problem. After the orientation change the layout didn't change.
Then I understood one simple idea - layout should depend on screen width that should be calculated inside render function, i.e.
getScreen = () => {
return Dimensions.get('screen');
}
render () {
return (
<View style={{ width: this.getScreen().width }>
// your code
</View>
);
}
In that case, the width will be calculated at the moment of render.
** I am using this logic for my landscape and portrait Logic.**
** by this if I launch my app in landscape first I am getting the real height of my device. and manage the hight of the header accordingly.**
const [deviceOrientation, setDeviceOrientation] = useState(
Dimensions.get('window').width < Dimensions.get('window').height
? 'portrait'
: 'landscape'
);
const [deviceHeight, setDeviceHeight] = useState(
Dimensions.get('window').width < Dimensions.get('window').height
? Dimensions.get('window').height
: Dimensions.get('window').width
);
useEffect(() => {
const setDeviceHeightAsOrientation = () => {
if (Dimensions.get('window').width < Dimensions.get('window').height) {
setDeviceHeight(Dimensions.get('window').height);
} else {
setDeviceHeight(Dimensions.get('window').width);
}
};
Dimensions.addEventListener('change', setDeviceHeightAsOrientation);
return () => {
//cleanup work
Dimensions.removeEventListener('change', setDeviceHeightAsOrientation);
};
});
useEffect(() => {
const deviceOrientation = () => {
if (Dimensions.get('window').width < Dimensions.get('window').height) {
setDeviceOrientation('portrait');
} else {
setDeviceOrientation('landscape');
}
};
Dimensions.addEventListener('change', deviceOrientation);
return () => {
//cleanup work
Dimensions.removeEventListener('change', deviceOrientation);
};
});
console.log(deviceHeight);
if (deviceOrientation === 'landscape') {
return (
<View style={[styles.header, { height: 60, paddingTop: 10 }]}>
<TitleText>{props.title}</TitleText>
</View>
);
} else {
return (
<View
style={[
styles.header,
{
height: deviceHeight >= 812 ? 90 : 60,
paddingTop: deviceHeight >= 812 ? 36 : 10
}
]}>
<TitleText>{props.title}</TitleText>
</View>
);
}
I have, by far, had the most success with this library: https://github.com/axilis/react-native-responsive-layout
It does what you are asking for and a lot more. Simple Component implementation without hardly any logic like some of the more complex answers above. My project is using Phone, Tablet, and web via RNW - and the implementation is flawless. Additionally when resizing the browser it's truly responsive, and not just on initial rendering - handling phone orientation changes flawlessly.
Example code (Put any components as children of blocks):
<Grid>
<Section> {/* Light blue */}
<Block xsSize="1/1" smSize="1/2" />
<Block xsSize="1/1" smSize="1/2" />
<Block xsSize="1/1" smSize="1/2" />
</Section>
<Section> {/* Dark blue */}
<Block size="1/1" smSize="1/2" />
<Block size="1/1" smSize="1/2" />
<Block size="1/1" smSize="1/2" />
<Block size="1/1" smSize="1/2" />
<Block size="1/1" smSize="1/2" />
</Section>
</Grid>
To give this:
I have written a HoC solution for my expo SDK36 project, it support orientation change and pass props.orientation based on ScreenOrientation.Orientation value.
import React, { Component } from 'react';
import { ScreenOrientation } from 'expo';
export default function withOrientation(Component) {
class DetectOrientation extends React.Component {
constructor(props) {
super(props);
this.state = {
orientation: '',
};
this.listener = this.listener.bind(this);
}
UNSAFE_componentWillMount() {
this.subscription = ScreenOrientation.addOrientationChangeListener(this.listener);
}
componentWillUnmount() {
ScreenOrientation.removeOrientationChangeListener(this.subscription);
}
listener(changeEvent) {
const { orientationInfo } = changeEvent;
this.setState({
orientation: orientationInfo.orientation.split('_')[0],
});
}
async componentDidMount() {
await this.detectOrientation();
}
async detectOrientation() {
const { orientation } = await ScreenOrientation.getOrientationAsync();
this.setState({
orientation: orientation.split('_')[0],
});
}
render() {
return (
<Component
{...this.props}
{...this.state}
onLayout={this.detectOrientation}
/>
);
}
}
return (props) => <DetectOrientation {...props} />;
}
To achieve a more performant integration, I used the following as a superclass for each of my react-navigation screens:
export default class BaseScreen extends Component {
constructor(props) {
super(props)
const { height, width } = Dimensions.get('screen')
// use this to avoid setState errors on unmount
this._isMounted = false
this.state = {
screen: {
orientation: width < height,
height: height,
width: width
}
}
}
componentDidMount() {
this._isMounted = true
Dimensions.addEventListener('change', () => this.updateScreen())
}
componentWillUnmount() {
this._isMounted = false
Dimensions.removeEventListener('change', () => this.updateScreen())
}
updateScreen = () => {
const { height, width } = Dimensions.get('screen')
if (this._isMounted) {
this.setState({
screen: {
orientation: width < height,
width: width, height: height
}
})
}
}
Set any root components to extend from this component, and then pass the screen state to your leaf/dumb components from the inheriting root components.
Additionally, to keep from adding to the performance overhead, change the style object instead of adding more components to the mix:
const TextObject = ({ title }) => (
<View style={[styles.main, screen.orientation ? styles.column : styles.row]}>
<Text style={[styles.text, screen.width > 600 ? {fontSize: 14} : null ]}>{title}</Text>
</View>
)
const styles = StyleSheet.create({
column: {
flexDirection: 'column'
},
row: {
flexDirection: 'row'
},
main: {
justifyContent: 'flex-start'
},
text: {
fontSize: 10
}
}
I hope this helps anyone in the future, and you'll find it to be quite optimal in terms of overhead.
I'm using styled-components, and this is how I re-render the UI on orientation change.
import React, { useState } from 'react';
import { View } from 'react-native';
import { ThemeProvider } from 'styled-components';
import appTheme from 'constants/appTheme';
const App = () => {
// Re-Layout on orientation change
const [theme, setTheme] = useState(appTheme.getTheme());
const onLayout = () => {
setTheme(appTheme.getTheme());
}
return (
<ThemeProvider theme={theme}>
<View onLayout={onLayout}/>
{/* Components */}
</ThemeProvider>
);
}
export default App;
Even if you're not using styled-components, you can create a state and update it on onLayout to re-render the UI.
This is my solution:
const CheckOrient = () => {
console.log('screenHeight:' + Dimensions.get('screen').height + ', screenWidth: ' + Dimensions.get('screen').width);
}
return ( <
View onLayout = {
() => CheckOrient()
} >
............
<
/View>
Note for the case with a pure component. #mridul-tripathi answer works correctly, but if a pure component is used, then probably only parent/top-level component reacting to orientation change is not enough. You will also need to update a pure component separately on orientation change.
All you need is:
import { useWindowDimensions } from 'react-native';
export default function useOrientation() {
const window = useWindowDimensions();
return window.height >= window.width ? 'portrait' : 'landscape';
}
You need useWindowDimensions
This hook re-render component when dimension change and apply styles but Dimensions object can't re-render component and change style, it just work in first render
import { useWindowDimensions } from 'react-native';
then destructure it
const { height, width } = useWindowDimensions();
and final you can do like this
import React from "react";
import { View, StyleSheet, useWindowDimensions } from "react-native";
const App = () => {
const { height, width } = useWindowDimensions();
const isPortrait = height > width;
return (
<View style={isPortrait ? styles.portrait : styles.landscape}>
{/* something */}
</View>
);
};
const styles = StyleSheet.create({
portrait: {},
landscape: {},
});
export default App;
also you can use scale property
const { scale } = useWindowDimensions();
read this document
https://reactnative.dev/docs/usewindowdimensions
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
Changing CSS styles when an event fires
I'm trying to integrate THEOPlayer in my project and I want to customize styles depending on certain events. For instance, I would love to hide the toolbar and show an overlay image when the video is paused. They do expose some CSS classes that I can change manually but my question is, how do I change the values in CSS on a specific event. Since the player is imported as a single JSX element I don't know how to add custom classes to its specific parts. So I would like to know if there is another way. Here is a component where an instance of Player is created: class Player extends React.Component { _player = null; _el = React.createRef(); componentDidMount() { const { source, onPlay, onPause } = this.props; if (this._el.current) { this._player = new window.THEOplayer.Player(this._el.current, { libraryLocation: "https://cdn.myth.theoplayer.com/7aff3fa6-f92e-45f9-a40e-1bce9911b073/", }); this._player.source = source; this._player.addEventListener("play", onPlay); this._player.addEventListener("pause", onPause); } } componentWillUnmount() { if (this._player) { this._player.destroy(); } } render() { return ( <div className={ "theoplayer-container video-js theoplayer-skin vjs-16-9 THEOplayer" } ref={this._el} > </div> ); } } export default Player; And that's a part of code where I want to change styles onPlay and onPause <div className={"player-container"}> <Player source={source} onPlay={() => { console.log("playing"); }} onPause={() => { console.log("paused"); }} /> </div>
Use like this state = { play: false, pause: true, } const playFn = () => { this.setState = ({ play: true, pause: false, }) } const pauseFn = () => { this.setState = ({ play: false, pause: true, }) } <div className={"player-container"}> <Player source={source} onPlay={playFn} onPause={pauseFn} activatePlayClasses={play} activatePauseClasses={pause} bg={'https://example/example.jpg'} /> </div> // on Player component const { source, onPlay, onPause, activatePauseClasses, activatePlayClasses , bg} = this.props; render() { return ( <div className={ `theoplayer-container video-js theoplayer-skin vjs-16-9 THEOplayer ${activatePauseClasses ? 'your pause class' : ''} ${activatePlayClasses ? 'your play class' : ''}` } style={{backgroundImage: `url(${bg})`}} ref={this._el} > </div> ); } I have updated code
React Native: Dynamically change style with AsyncStorage and States
I want to implement dark mode and black mode in my app and the way I have it is that the user toggles on dark/black mode from one class in which I want the state to be updated to all the classes, the toggle class is as followed: AppearanceToggle Class state = { BlackModeValue: null, DarkModeValue: null }; componentDidMount = () => { AsyncStorage.getItem('DarkModeValue').then(value => this.setState({ DarkModeValue: JSON.parse(value) })); AsyncStorage.getItem('BlackModeValue').then(value => this.setState({ BlackModeValue: JSON.parse(value) })); }; //AsyncStorage.setItem ......... render() { return ( <ScrollView style={[ styles.View , this.state.DarkModeValue ? darkmode.ASView : null || this.state.BlackModeValue ? blackmode.ASView : null ]}> <SettingsList borderColor='#c8c7cc' defaultItemSize={50}> <SettingsList.Item hasSwitch={true} switchState={this.state.DarkModeValue} switchOnValueChange={//Goes to asyncStorage.setItem method} title='Dark Mode' /> <SettingsList.Item hasSwitch={true} switchState={this.state.BlackModeValue} switchOnValueChange={//Goes to asyncStorage.setItem method} title='Black Mode' /> </SettingsList> </ScrollView> ); } } And then in the class (which is SettingsScreen.js, this is the screen that navigates to AppearanceToggle ) that I want to .getItem and change the state is as followed: state = { switchValue: false, rated: false, DarkModeValue:null, BlackModeValue:null, }; componentDidMount = () => { AsyncStorage.getItem('DarkModeValue').then(value => this.setState({ DarkModeValue: JSON.parse(value) })); AsyncStorage.getItem('BlackModeValue').then(value => this.setState({ BlackModeValue: JSON.parse(value) })); }; render() { return ( <ScrollView style={[ styles.View , this.state.DarkModeValue ? styles.DMView : null || this.state.BlackModeValue ? styles.BMView : null ]}> .......... </ScrollView> The problem I have is that when I change the switch, it affects the AppearanceToggleScreen Class instantly but not the SettingsScreen UNLESS I refresh the app. Is there a way to do it so all of them get affected instantly?
Perhaps the best way to propagate it is to listen for the changes in your AppComponent using Context or root component. e.g. So you would create a theme context like : export const themes = { blackMode: { foreground: '#000000', background: '#eeeeee', }, darkMode: { foreground: '#2f4f4ff', background: '#222222', }, }; export const ThemeContext = React.createContext( themes.darkMode // default value ) ; Your AppearanceToggle class would have something like : import {ThemeContext} from './theme-context'; class ThemedButton extends Component { render() { let props = this.props; let theme = this.context; return ( <button {...props} style={{backgroundColor: theme.background}} /> ); } } ThemedButton.contextType = ThemeContext; export default ThemedButton; And then your AppComponent could be import {ThemeContext, themes} from './theme-context'; import ThemedButton from './themed-button'; function Toolbar(props) { // Render your customized toolbar here and bind the changeTheme function to it } class App extends Component { constructor(props) { super(props); }; componentDidMount = () => { AsyncStorage.getItem('selectedTheme').then(value => this.setState({ selectedTheme: JSON.parse(value) })); }; this.toggleTheme = () => { this.setState(state => ({ theme: state.theme === themes.darkMode ? themes.blackMode : themes.darkMode, })); }; } render() { // The ThemedButton button inside the ThemeProvider // uses the theme from state while the one outside uses // the default dark theme return ( <Page> <ThemeContext.Provider value={this.state.theme}> <Toolbar changeTheme={this.toggleTheme} /> </ThemeContext.Provider> <Section> <ThemedButton /> </Section> </Page> ); } } For more read
The thing is that in the AppearanceToggleScreen you're changing the state, therefore the component is rerendered (with the new theme), but because the SettingsScreen is already in the navigation stack (because that's where you're navigating from) the componentDidMount is not executing again. Now, maybe you want to use the Context API to access globally to the values, or do something like this.
Updating styles of a styled-component on props change slow?
In my parent component i have a onScroll Listener that determines whether i hit a specific point when scrolling. There is a boolean stored in the state. I pass this state variable down to a child. In that child i have a styled component that changes with the boolean state variable that was passed down as props. When i scroll really fast the css seems to change very slow. Is there anyway to speed this up? Parent Component: class Parent extends Component { constructor(props) { super(props); this.state = { flag: false } } componentDidMount() { var test = ReactDOM.findDOMNode(this.refs.test); test.addEventListener('scroll', this.handleScroll); } handleScroll = () => { if (test.scrollTop = 10) { this.setState({ flag: true }) } else { this.setState({ flag: false }) }; } render() { return ( <Component ref="test" > <Child flag={ this.state.flag }/> </Component> ) } } Child Component: const Container = styled.div` height: ${({flag})=>flag ? "10px" : "50px"} `; .... .... .... render(){ <Container flag={this.props.flag}/> } that is a very basic idea of what im doing in general, when i scroll really fast past the point of trigger it takes a slight second before rendering. Is there anyway i can avoid this delay and speed things up. Or is there a better way you guys recommend doing this.
In handleScroll method, you doesn't declare test. You should do like the following: class Parent extends Component { constructor(props) { super(props); this.state = { flag: false } } componentDidMount() { var test = ReactDOM.findDOMNode(this.refs.test); test.addEventListener('scroll', this.handleScroll); } handleScroll = (event) => { if (event.scrollTop = 10) { this.setState({ flag: true }) } else { this.setState({ flag: false }) }; } render() { return ( <Component ref="test"> <Child flag={ this.state.flag }/> </Component> ) } }
React Radium - How to change property values dynamically
I want to dynamically change, say, the background color of the button dynamically. If this is my radium js styles file: button-styles.js export const styles = { base: { backgroundColor: 'red', } }; button.js const myStyles = require('./styles/button-styles.js'); #Radium class MyButton extends Component { render() { {/* How do I tell the button to override the default value for background color of red, to the props value if it exists, (and in this scenario it does and is the color green)? */} return (<Button style={ ??? }>Click Me</Button>) } } MyButton.defaultProps = { btnBg: 'green' } MyButton.propTypes = { btnBg: PropTYpes.string } (A side note to the powers that be; there is no react-radium tag.)
You could create your styles as a function of your props. Advantage: You do not need to have the fetching algorithm which just basically assigns your styles. button-styles.js export default props => ({ backgroundColor: props.btnBg // if you need a default value you could use // props.btnBg || 'green' }) // You could even use ES6 object destruction export default ({btnBg}) => ({ backgroundColor: btnBg }) button.js const myStyles = require('./styles/button-styles.js'); #Radium class MyButton extends Component { render() { return <Button style={ myStyles(this.props) }>Click Me</Button> } } MyButton.defaultProps = { btnBg: 'green' } MyButton.propTypes = { btnBg: PropTypes.string }
Don't know if this is proper way to do it, but this worked for me. Default properties in base remained, while only those with a matching prop name in the dynamicStyle prop object were affected. So in this example color and fontSize were not affected and remained with the return settings, with only backgroundColor now being green.. UPDATE: Per Janaka Stevens recommendation, I made the settings immutable. But I did so in the fetchBtnStyle method and not a hard coding in the component per Janaka Stevens' idea (ie the color property), because I theorize I would have no clue what property the user may wish to change; the user may want to change color, font-size or background-color. button-styles.js const styleValues = { base: { fontSize: '1.0em', color: '#fff', backgroundColor: 'red', } }; module.exports = { fetchBtnStyle(values) { const settings = {}; // making the value immutable here <------------- Object.assign(settings, styleValues.base) if (values !== undefined) { Object.assign(settings, values); } return settings; } }; button.js import btnStyles = require('./styles/button-styles.js'); #Radium class MyButton extends Component { render() { return ( <Button style={ btnStyles.fetchBtnStyle(this.props.dynamicStyle) }> Click Me </Button>) } } MyButton.defaultProps = { dynamicStyle: { backgroundColor: 'green' } } MyButton.propTypes = { dynamicStyle: PropTypes.object }
The style needs to be immutable so you will want to define it in the render like so. class MyButton extends Component { render() { let btnSty = MyStyles.base; if (this.props.dynamicSty) btnSty.color = this.props.dynamicSty.color; else btnSty.color = MyStyles.base.color; return ( <Button style={btnSty}> Click Me </Button>) } }