Angular & RxJS5 - 从 http & socket 更新数据

Question

我有一个场景需要：

1. 获取路由参数
2. 使用路由参数调用http服务
3. 一旦 http 响应，使用相同的路由参数调用套接字服务
4. 每次socket响应，从http服务更新数据

理想情况下，我希望将其保存在流中。

如果我可以使用CombineLatest？还是涉及Scan 运营商？

this.data$ = this.route.params
               .switchMap(params => {
                   return Observable.forkJoin([
                       Observable.of(params),
                       this.http.get('api', { prop1: params.prop1, prop2: params.prop2 })
                   ])
               }).combineLatest(([params, data]) => {
                    this.socket.get('event', { prop1: params.prop1, prop2: params.prop2 }),
                        updateData
                })


    private updateData(data, socketData): any[] {
        //only returns data = [params, data]
        //socketData always undef
        return data;
    }

Answer 1

根据我对您的流程的理解，我不需要您需要任何 combineLatest 或 scan 运算符，您只需要嵌套两个 switchMaps：

this.data$ = this.route.params
                .switchMap(params => this.http.get('api', { prop1: params.prop1, prop2: params.prop2 })
                    .switchMap(httpResult => this.socket.get('event', { prop1: params.prop1, prop2: params.prop2 }) // assuming socket.get(...) is a perpetual stream
                        .map(socketResult => doWhateverCombinationWith(httpResult, socketResult))
                        .startWith(httpResult); // not sure if this is required, your question is kind of vague, but essentially this will cause the stream to emit the original httpResult before there is socketData
                    )
                );