[英]Is it an anti pattern that Promise with resolve and reject as property?why?
export function getDeferred () {
let resolve; let reject;
const promise = new Promise((res, rej) => {
resolve = res;
reject = rej;
});
promise.resolve = resolve;
promise.reject = reject;
return promise ;
};
let deferred=getDeferred();
async function fetchSomeData(){
let data=await fetch('...')
deferred.resolve(data);
}
async function someFunctionMustHaveFetchedData(){
let data = await deferred;
// do something after deferred resolved
}
why am i doing this?我为什么要这样做?
someFunctionMustHaveFetchData will be called many times but data should only be fetch once someFunctionMustHaveFetchData 将被调用多次,但数据只能获取一次
It's probably not an "anti-pattern" per se, but I would only expose reject
and resolve
if you absolutely have to.它本身可能不是“反模式”,但我只会在绝对必要的情况下公开
reject
和resolve
。 Which is not the case here.这不是这里的情况。 You can just store the promise or the data in a variable:
您可以只将 promise 或数据存储在变量中:
let promise;
async function someFunctionMustHaveFetchedData(){
if (!promise) {
promise = fetch('...');
}
let data = await promise;
// do something after deferred resolved
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.