next
Version:
The React Framework
56 lines (55 loc) • 2.57 kB
JavaScript
import { Children, useEffect, useLayoutEffect } from 'react';
const isServer = typeof window === 'undefined';
const useClientOnlyLayoutEffect = isServer ? ()=>{} : useLayoutEffect;
const useClientOnlyEffect = isServer ? ()=>{} : useEffect;
export default function SideEffect(props) {
const { headManager, reduceComponentsToState } = props;
function emitChange() {
if (headManager && headManager.mountedInstances) {
const headElements = Children.toArray(Array.from(headManager.mountedInstances).filter(Boolean));
headManager.updateHead(reduceComponentsToState(headElements, props));
}
}
if (isServer) {
var _headManager_mountedInstances;
headManager == null ? void 0 : (_headManager_mountedInstances = headManager.mountedInstances) == null ? void 0 : _headManager_mountedInstances.add(props.children);
emitChange();
}
useClientOnlyLayoutEffect(()=>{
var _headManager_mountedInstances;
headManager == null ? void 0 : (_headManager_mountedInstances = headManager.mountedInstances) == null ? void 0 : _headManager_mountedInstances.add(props.children);
return ()=>{
var _headManager_mountedInstances;
headManager == null ? void 0 : (_headManager_mountedInstances = headManager.mountedInstances) == null ? void 0 : _headManager_mountedInstances.delete(props.children);
};
});
// We need to call `updateHead` method whenever the `SideEffect` is trigger in all
// life-cycles: mount, update, unmount. However, if there are multiple `SideEffect`s
// being rendered, we only trigger the method from the last one.
// This is ensured by keeping the last unflushed `updateHead` in the `_pendingUpdate`
// singleton in the layout effect pass, and actually trigger it in the effect pass.
useClientOnlyLayoutEffect(()=>{
if (headManager) {
headManager._pendingUpdate = emitChange;
}
return ()=>{
if (headManager) {
headManager._pendingUpdate = emitChange;
}
};
});
useClientOnlyEffect(()=>{
if (headManager && headManager._pendingUpdate) {
headManager._pendingUpdate();
headManager._pendingUpdate = null;
}
return ()=>{
if (headManager && headManager._pendingUpdate) {
headManager._pendingUpdate();
headManager._pendingUpdate = null;
}
};
});
return null;
}
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