将观察者存储在全局变量中并在以后使用它 [英] Storing observer in a global variable and use it later

问题描述

如何在代码中创建一个observable并在后面生成下一个值？我希望能够通过其他异步事件从代码的不同部分调用onNext。

How can I create an observable and generate the next value later in the code? I would like to be able to call onNext from different parts of the code as a result of other async events.

这是我试过的，但是不起作用：

This is what I have tried, which doesn't work:

var Rx = require('rx');

var GlobalObserver;

var source = Rx.Observable.create(observer => {
    GlobalObserver = observer;
});

var subscription = source.subscribe(
    x => console.log('onNext: %s', x),
    e => console.log('onError: %s', e),
    () => console.log('onCompleted')
);

//...later in the code, as a result of another async event:


    GlobalObserver.onNext(someData);
    ...
    GlobalObserver.onNext(someOtherData);

推荐答案

您需要的是某种主题。 ReplaySubject ， BehaviorSubject ，主题等

What you need is a subject of some sort. ReplaySubject, BehaviorSubject, Subject, etc.

创建一个主题，然后你可以 subject.subscribe（...）订阅它。您也可以 subject.onNext（...）添加到流中。

Create a subject, then you can do subject.subscribe(...) to subscribe to it. You can also do subject.onNext(...) to add to the stream.

例如：

var subject = new Rx.Subject();

var subscription = subject.subscribe(
    function (x) { console.log('onNext: ' + x); },
    function (e) { console.log('onError: ' + e.message); },
    function () { console.log('onCompleted'); }
);

subject.onNext(1);
// => onNext: 1

subject.onNext(2);
// => onNext: 2

subject.onCompleted();
// => onCompleted

subscription.dispose();

更具体的用例（每次成功的HTTP响应返回时都会添加到可观察流） ：

A more specific use case (will add to the observable stream every time a successful HTTP response comes back):

var httpResponseStream = new Rx.Subject();

var subscription = httpResponseStream.subscribe(function (response) { 
    console.log('HTTP response success: ', response); 
});

makeAJAXCall().then(function (response) {
    httpResponseStream.onNext(response);
});

正如另一位用户所说，请确保更改所有 onNext 到下一步。如果您使用的是V4，请坚持 onNext 。

As another user stated, make sure you change all onNext's to next if you are using V5. If you are using V4, stick to onNext.

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