Created
November 26, 2020 18:56
-
-
Save xettri/cfb3a9b8982f91717f4b2e2a12199a83 to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import React, { Component } from 'react'; | |
import PropTypes from 'prop-types'; | |
const throttle = (delay, noTrailing, callback, debounceMode) => { | |
let timeoutID; | |
let cancelled = false; | |
let lastExec = 0; | |
function clearExistingTimeout() { | |
if (timeoutID) { | |
clearTimeout(timeoutID); | |
} | |
} | |
function cancel() { | |
clearExistingTimeout(); | |
cancelled = true; | |
} | |
if (typeof noTrailing !== 'boolean') { | |
debounceMode = callback; | |
callback = noTrailing; | |
noTrailing = undefined; | |
} | |
function wrapper(...arguments_) { | |
let self = this; | |
let elapsed = Date.now() - lastExec; | |
if (cancelled) { | |
return; | |
} | |
function exec() { | |
lastExec = Date.now(); | |
callback.apply(self, arguments_); | |
} | |
function clear() { | |
timeoutID = undefined; | |
} | |
if (debounceMode && !timeoutID) { | |
exec(); | |
} | |
clearExistingTimeout(); | |
if (debounceMode === undefined && elapsed > delay) { | |
exec(); | |
} else if (noTrailing !== true) { | |
timeoutID = setTimeout( | |
debounceMode ? clear : exec, | |
debounceMode === undefined ? delay - elapsed : delay, | |
); | |
} | |
} | |
wrapper.cancel = cancel; | |
return wrapper; | |
}; | |
class InfiniteScrollComponent extends Component { | |
constructor(props) { | |
super(props); | |
this.scrollListener = throttle(150, this.onScrollListener).bind(this); | |
this.eventListenerOptions = this.eventListenerOptions.bind(this); | |
this.mousewheelListener = this.mousewheelListener.bind(this); | |
} | |
/* true if action triggered */ | |
actionTriggered = false; | |
componentDidMount() { | |
this.options = this.eventListenerOptions(); | |
this.attachScrollListener(); | |
} | |
componentDidUpdate() { | |
this.attachScrollListener(); | |
} | |
componentWillUnmount() { | |
this.detachScrollListener(); | |
this.detachMousewheelListener(); | |
} | |
UNSAFE_componentWillReceiveProps(props) { | |
// do nothing when dataLength is unchanged | |
const { dataLength } = this.props; | |
if (dataLength === props.dataLength) return; | |
this.actionTriggered = false; | |
} | |
// check passive support for browser | |
isPassiveSupported() { | |
let passive = false; | |
const testOptions = { | |
// eslint-disable-next-line getter-return | |
get passive() { | |
passive = true; | |
}, | |
}; | |
try { | |
document.addEventListener('test', null, testOptions); | |
document.removeEventListener('test', null, testOptions); | |
} catch (e) {} | |
return passive; | |
} | |
eventListenerOptions() { | |
let options = this.props.useCapture; | |
if (this.isPassiveSupported()) { | |
options = { | |
useCapture: this.props.useCapture, | |
passive: true, | |
}; | |
} else { | |
options = { passive: false }; | |
} | |
return options; | |
} | |
detachMousewheelListener() { | |
let scrollEl = window; | |
if (this.props.useWindow === false) { | |
scrollEl = this.scrollComponent.parentNode; | |
} | |
scrollEl.removeEventListener( | |
'mousewheel', | |
this.mousewheelListener, | |
this.options ? this.options : this.props.useCapture, | |
); | |
} | |
detachScrollListener() { | |
let scrollEl = window; | |
if (this.props.useWindow === false) { | |
scrollEl = this.getParentElement(this.scrollComponent); | |
} | |
scrollEl.removeEventListener( | |
'scroll', | |
this.scrollListener, | |
this.options ? this.options : this.props.useCapture, | |
); | |
scrollEl.removeEventListener( | |
'resize', | |
this.scrollListener, | |
this.options ? this.options : this.props.useCapture, | |
); | |
} | |
getParentElement(el) { | |
if (this.props.parent instanceof HTMLElement) { | |
return this.props.parent; | |
} | |
if (typeof this.props.parent === 'string') { | |
const elm = document.getElementById(this.props.parent); | |
if (elm !== null) return elm; | |
} | |
const scrollParent = | |
this.props.getScrollParent && this.props.getScrollParent(); | |
if (scrollParent != null) { | |
return scrollParent; | |
} | |
return el && el.parentNode; | |
} | |
attachScrollListener() { | |
const parentElement = this.getParentElement(this.scrollComponent); | |
if (!this.props.hasMore || !parentElement) return; | |
let scrollEl = window; | |
if (this.props.useWindow === false) { | |
scrollEl = parentElement; | |
} | |
scrollEl.addEventListener( | |
'mousewheel', | |
this.mousewheelListener, | |
this.options ? this.options : this.props.useCapture, | |
); | |
scrollEl.addEventListener( | |
'scroll', | |
this.scrollListener, | |
this.options ? this.options : this.props.useCapture, | |
); | |
scrollEl.addEventListener( | |
'resize', | |
this.scrollListener, | |
this.options ? this.options : this.props.useCapture, | |
); | |
if (this.props.initialLoad) { | |
this.scrollListener(); | |
} | |
} | |
/* | |
Prevents Chrome hangups | |
https://github.com/TryGhost/Ghost/issues/7934 | |
*/ | |
mousewheelListener(e) { | |
if (e.deltaY === 1 && !this.isPassiveSupported()) { | |
e.preventDefault(); | |
} | |
} | |
onScrollListener() { | |
const el = this.scrollComponent; | |
const scrollEl = window; | |
const parentNode = this.getParentElement(el); | |
// terminate if not data or under process | |
if ( | |
(typeof this.props.dataLength === 'number' && this.actionTriggered) || | |
!this.props.hasMore | |
) { | |
return; | |
} | |
let offset; | |
if (this.props.useWindow) { | |
const doc = | |
document.documentElement || document.body.parentNode || document.body; | |
const scrollTop = | |
scrollEl.pageYOffset !== undefined | |
? scrollEl.pageYOffset | |
: doc.scrollTop; | |
offset = this.calculateOffset(el, scrollTop); | |
} else { | |
offset = el.scrollHeight - parentNode.scrollTop - parentNode.clientHeight; | |
} | |
if ( | |
offset < Number(this.props.threshold) && | |
el && | |
el.offsetParent !== null | |
) { | |
this.detachScrollListener(); | |
this.beforeScrollHeight = parentNode.scrollHeight; | |
this.beforeScrollTop = parentNode.scrollTop; | |
if (typeof this.props.loadMore === 'function') { | |
this.props.loadMore(); | |
if (typeof this.props.dataLength === 'number') { | |
this.actionTriggered = true; | |
} | |
} | |
} | |
} | |
calculateOffset(el, scrollTop) { | |
if (!el) return 0; | |
return ( | |
this.calculateTopPosition(el) + | |
(el.offsetHeight - scrollTop - window.innerHeight) | |
); | |
} | |
calculateTopPosition(el) { | |
if (!el) return 0; | |
return el.offsetTop + this.calculateTopPosition(el.offsetParent); | |
} | |
render() { | |
const renderProps = this.props; | |
const { | |
children, | |
element, | |
hasMore, | |
initialLoad, | |
loader, | |
loadMore, | |
ref, | |
threshold, | |
useCapture, | |
useWindow, | |
getScrollParent, | |
parent, | |
dataLength, | |
...props | |
} = renderProps; | |
props.ref = node => { | |
this.scrollComponent = node; | |
if (ref) { | |
ref(node); | |
} | |
}; | |
// return children if no any element defined | |
if (!element) { | |
return <>{children}</>; | |
} | |
return React.createElement(element, props, [children]); | |
} | |
} | |
const InfiniteScroll = props => { | |
const { loader, ...rest } = props; | |
return ( | |
<> | |
<InfiniteScrollComponent {...rest} /> | |
{props.hasMore && loader ? loader : null} | |
</> | |
); | |
}; | |
InfiniteScroll.defaultProps = { | |
element: 'div', | |
hasMore: false, | |
initialLoad: true, | |
loader: null, | |
ref: null, | |
threshold: 250, | |
useWindow: true, | |
useCapture: false, | |
getScrollParent: null, | |
parent: null, | |
dataLength: null, | |
}; | |
InfiniteScroll.propTypes = { | |
children: PropTypes.node.isRequired, | |
element: PropTypes.node, | |
hasMore: PropTypes.bool, | |
initialLoad: PropTypes.bool, | |
loader: PropTypes.node, | |
loadMore: PropTypes.func.isRequired, | |
ref: PropTypes.func, | |
getScrollParent: PropTypes.func, | |
threshold: PropTypes.number, | |
useCapture: PropTypes.bool, | |
useWindow: PropTypes.bool, | |
parent: PropTypes.any, | |
dataLength: PropTypes.number, | |
}; | |
export default InfiniteScroll; |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment