何时使用Promise over Observable? [英] When to use Promise over observable?

问题描述

在任何情况下，Promise都比可观察的功能更强大吗?我知道可观察到的东西比诺言有很多好处.但是，无论如何，我应该只对可观察对象使用promise.

Is there any case, where Promise is more powerful as compare to observable? I know a lot of benefits of observables over promises. But Is there any case, I should use only promises over observables.

我找到了此链接，承诺与可观察对象.但这始终向我展示了可观察性胜于承诺的好处.我想知道承诺比可观察的好处.

I found this link, promises vs observables. But this always shows me the benefits of observables over promises. I want to know the benefits of promise over observables.

推荐答案

一个可观察者可以做诺言所能做的一切.始终可以使用toPromise()方法将其切换为诺言，以防出现诺言.

An observable does everything that a promise does and more. It can always be switched to a promise with toPromise() method in case a promise is expected.

如果可以的话，必须选择一个可观察的

An observable must be chosen over a promise if

• 可观察物固有的但不是承诺的任何特征，并且在相关问题中有详细说明需求(特别是取消订阅，不完整的可观测值和接收多个值的可观测值)
消耗它的
• API期望可观察到的，并且不使用Observable.from(...)安全结构来统一可观察到的事物和诺言

• any features that are intrinsic to observables and not promises and explained in detail in related question is in demand (notably unsubscription, incomplete observables and observables that receive multiple values)
• API that consumes it expects an observable and doesn't use Observable.from(...) safety structure to unify observables and promises

如果使用的代码专门使用可观察对象，则可以在promise上选择可观察的 .

An observable may be chosen over a promise if the code where it's used uses observables exclusively.

一个承诺 .

如果可观察的话，可能会选择一个

A promise may be chosen over an observable if

• 使用其代码的代码专门使用promises(特别是async函数)
• 它必须在设计上是异步的
• 它必须立即订阅并链接然后，因为在可观察对象let observable = ...; observable.subscribe(...); return observable中应该断开一条链(这也需要跟踪多个订阅，以防可观察对象可取消)

• the code where it's used uses promises exclusively (notably async functions)
• it needs to be asynchronous by design
• it needs to be immediately subscribed and chained then, because a chain should be broken in observables let observable = ...; observable.subscribe(...); return observable (this also requires multiple subscriptions to be tracked in case an observable is cancellable)

这篇关于何时使用Promise over Observable?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！