const ServerMock = {
count: 0,
getData() {
if (this.count === 2) {
return Promise.resolve([{
name: "SomeName" }]);
} else {
this.count++;
return Promise.reject("Error");
}
}
};
function fetchData(limit, time) {
return {
then(resolve, reject) {
const retry = setInterval(async () => {
limit--;
try {
console.log("Trying....");
const data = await ServerMock.getData();
if (data) {
console.log("Resolve");
clearInterval(retry);
resolve(data);
}
} catch {
if (limit === 0) {
clearInterval(retry);
reject("Limit Reached");
}
}
}, time);
}
};
}
// 轮询的时间为100，轮询的最大次数为3
(async () => {
try {
const result = await fetchData(3, 1000);
console.log(result);
} catch (err) {
console.log(err);
}
})();
The above is polling at intervals, we can also poll continuously instead of setting the interval
const ServerMock = {
count: 0,
getData() {
console.log('调用')
if (this.count === 2) {
return Promise.resolve([{
name: "SomeName" }]);
} else {
this.count++;
return Promise.reject("Error");
}
}
};
const retry = (attempts, action) => {
console.log('todo')
const promise = action()
return attempts > 0 ? promise.catch(() => retry(attempts - 1, action)) : promise
}
(async () => {
let res = await retry(5, () => ServerMock.getData())
console.log(res)
})