import { useCallback, useState, useContext, useEffect } from "react";
import { useNavigate, UNSAFE_NavigationContext } from "react-router-dom";
export const useTest = (
when: boolean,
onSuccess: () => void
): {
navigationWasBlocked: boolean;
handleCancel: () => void;
handleOk: () => void;
} => {
const [nextLocation, setNextLocation] = useState(null);
const { navigator } = useContext(UNSAFE_NavigationContext);
const navigate = useNavigate();
console.log("setNextLocation outer ", nextLocation);
const handleCancel = () => {
//点击取消按钮调用此方法，清空当前要跳转到的链接
setNextLocation(undefined);
};
const handleOk = () => {
//点击了同意按钮
debugger;
onSuccess(); //先调用回调函数，此函数在调用此hook时传入
setNextLocation(undefined); //跳转完毕后清空，因为setState的异步性，放这里和放最后一样
navigate(nextLocation); //跳转到当前需要跳转的链接，虽然上面设置了undefind但是由于异步性这里获取的还是未清空时的链接
};
const blocker: any = useCallback(
({ action, location: nextLocation, retry }) => {
console.log("location ", location);
debugger;
switch (action) {
case "REPLACE": {
retry();
return;
}
case "POP":
case "PUSH": {
//POP：点击浏览器后退按钮
//PUSH: 点击了某个按钮跳转页面
setNextLocation(nextLocation); //无论是哪种，都把当前要跳转到的链接信息放入currentLocation
return;
}
default:
break;
}
},
[]
);
//调用此hook
// const { navigationWasBlocked, handleCancel, handleOk } = useTest(true, () => {
// console.log('called');
// });
useEffect(() => {
if (!when) return; //当when为false时表示不需要启用此功能
if (nextLocation) return; //如果NextLocation存在值就跳出
if (!("block" in navigator)) return; //block属性不存在就跳出，浏览器兼容？
const unblock = (navigator as any).block((tx: any) => {
debugger;
console.log("tttttttttt ", tx.retry.toString());
//监听路由变化，每当点击跳转按钮会调用此函数
//这个函数会传入tx，形如：
// {
// "action": "PUSH",
// "location": {
// "pathname": "/dummy-test-01",
// "hash": "",
// "search": "",
// "state": null,
// "key": "igdvd1g0"
// }
// "retry":function(){go(delta * -1);}
// }
// debugger;
// if (tx.action === "POP") {
// tx.action = "REPLACE";
// }
const autoUnblockingTx = {
...tx,
retry() {
//扩展retry方法
//如果Replace的情况就会走到这里
//第一步把绑定的监听事件移除
unblock();
//接着调tx上的retry方法
//go(delta * -1) 比如点击后退delta为1，变成go(-1)，改变url
tx.retry();
},
};
blocker(autoUnblockingTx); //调用blocker函数(设置当前router信息)
});
console.log("unblock ", unblock);
return unblock; //返回block函数的调用结果（是一个function组件卸载时调用此function）移除beforeunload listener
}, [navigator, blocker, when, nextLocation]);
return {
navigationWasBlocked: Boolean(nextLocation),
handleCancel,
handleOk,
};
};
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