0

我需要通过一个主题代理所有不同的事件流。

我想出了这段代码：

var mySubject,
    getObservable;

getObservable = function (subject, eventName) {
    return subject
        .asObservable()
        .filter(function (x) {
            return x.EventName === eventName;
        })
        .flatMap(function (x) {
            if (x.Type === 'onNext') {
                return Rx.Observable.return(x.Data);
            }

            if (x.Type === 'onError') {
                return Rx.Observable.throw(x.Data);
            }

            return Rx.Observable.empty();
        });
};

mySubject = new Rx.Subject();

getObservable(mySubject, 'foo')
    .subscribe(function(x){ 
        console.log('foo onNext ' + x); 
    }, function(x){ 
        console.log('foo onError ' + x); 
    }, function(){ 
        console.log('foo onComplete');
    });

getObservable(mySubject, 'bar')
    .subscribe(function(x){ 
        console.log('bar onNext ' + x); 
    }, function(x){ 
        console.log('bar onError ' + x); 
    }, function(){ 
        console.log('bar onComplete');
    });

mySubject.onNext({Type: 'onNext', EventName: 'foo', Data: 5});
mySubject.onNext({Type: 'onCompleted', EventName: 'foo'});

mySubject.onNext({Type: 'onNext', EventName: 'bar', Data: 5});
mySubject.onNext({Type: 'onError', EventName: 'bar', Data: 'Error message'});

得到输出：

foo onNext 5

bar onNext 5
bar onError Error message

预期输出：

foo onNext 5  
foo onCompleted

bar onNext 5
bar onError Error message

对于bar事件，它就像一个魅力：onNext将被传播，一旦错误引发，onError函数就会被调用并且事件流结束。但是，我无法让它为onComplete.

每当发出完整的通知时，我确实会看到它Rx.Observable.empty()被调用，但这不会导致订阅者onComplete处理程序被调用。相反，它调用它的onNext处理程序。

4

2 回答 2

1

该getObservable函数返回一个订阅eventName通过 a 发送的事件的 observable subject。

let getObservable = function (subject, eventName) {
    return Rx.Observable.create(function (observer) {
        subject
            .asObservable()
            .filter(function(x) {
                return x.EventName === eventName;
            })
            .map(function(x) {
                if (x.Type === 'onNext') {
                    observer.onNext(x.Data);
                }

                if (x.Type === 'onError') {
                    observer.onError(x.Data);
                }

                if (x.Type === 'onCompleted') {
                    observer.onCompleted();
                }

                return x;
            })
            .subscribe();
    });
};

这是一个使用来自原始问题的数据的工作示例：

var mySubject,
    getObservable;

getObservable = function (subject, eventName) {
    return Rx.Observable.create(function (observer) {
        subject
            .asObservable()
            .filter(function(x) {
                return x.EventName === eventName;
            })
            .map(function(x) {
                if (x.Type === 'onNext') {
                    observer.onNext(x.Data);
                }

                if (x.Type === 'onError') {
                    observer.onError(x.Data);
                }
                
                if (x.Type === 'onCompleted') {
                    observer.onCompleted();
                }
                
                return x;
            })
            .subscribe();
    });
};

mySubject = new Rx.Subject();

getObservable(mySubject, 'foo')
    .subscribe(function(x){ 
        console.log('SomethingHappened onNext ' + x); 
    }, function(x){ 
        console.log('SomethingHappened onError ' + x); 
    }, function(){ 
        console.log('SomethingHappened onComplete');
    });


getObservable(mySubject, 'bar')
    .subscribe(function(x){ 
        console.log('DataUpdated onNext ' + x); 
    }, function(x){ 
        console.log('DataUpdated onError ' + x); 
    }, function(){ 
        console.log('DataUpdated onComplete');
    });

mySubject.onNext({Type: 'onNext', EventName: 'foo', Data: 5});
mySubject.onNext({Type: 'onCompleted', EventName: 'foo'});

mySubject.onNext({Type: 'onNext', EventName: 'bar', Data: 5});
mySubject.onNext({Type: 'onError', EventName: 'bar', Data: 'Error message'});
<script src='https://rawgit.com/Reactive-Extensions/RxJS/master/dist/rx.all.js'></script>

于 2012-03-06T10:49:43.803 回答
0

在 .NET Observable.SelectMany 中使用 Observable.Merge 将流合并到一个复合 observable 中。恕我直言 Observable.Merge 仅在任何合并的 observables 完成时完成。

例如http://theburningmonk.com/2010/02/rx-framework-iobservable-merge/

这可能是问题的原因。

于 2012-03-06T15:26:20.567 回答