Question

我想将http响应拆分为不同的Variables / Observables。

响应是Json：

with t (url) as (
  values 
    ('http://some.host/some/path?oid=abc123&other'), 
    ('http://some.host/some/path?other&oid=def456&foo=bar')
)
select split_part(substring(url from 'oid=\w+'), '=', 2)
from t;

在这里，我想将响应拆分为2个不同的Observable。

test.service.ts

split_part
----------
abc123    
def456

app.component.ts

[
  {
    "status": [
        { "id": 1, "value": "active"},
        { "id": 2, "value": "inactive"}
    ]
  },
  {
    "type": [
        { "id": 1, "value": "full"},
        { "id": 2, "value": "half"}
    ]
  }
]

错误： TypeError：无法读取未定义的属性'subscribe'

如果我记录组件，我看到变量status $被填充： status $：ScalarObservable {_isScalar：true，value：Array（2），scheduler：null}

我如何避免错误并使事情有效？

Answer 1

这样的事情：

getDropdowns(): Observable<MyType> { //Return the observable
    return this.http.get(this.url)
      .map((res) => <MyType>res.json());        
}

let response: Observable<MyType> = getDropdowns().publishReplay(1).refCount();// Cache the reponse
status$: Observable<DropdownOption[]> = response.map(x => x[0].status)//map to get the status
type$: Observable<DropdownOption[]> = response.map(x => x[1].type)//map fot the type

Answer 2

尝试这样做以避免错误：

<强> service.ts

getDropdowns(): void {
    this.http.get(this.url)
        .map((res) => {
            let data = <DropdownOption[]>res.json();
            for (let key in data) {
                for (let k in data[key]) {
                    return this[k + '$'] = Observable.of(data[key][k]);
                }
            }
        })
}

Answer 3

首先，知道为什么将其拆分为2个可观察对象会很有用，因为你只需要调用一个。

但是如果你想这样做，你应该使用Subjects and Observables：

private sub1: Subject<any> = new Subject();
private sub2: Subject<any> = new Subject();
private obs1: Observable<any> = this.sub.asObservable();
private obs2: Observable<any> = this.sub.asObservable();

yourFunction(): any {
  this.myHttpCall().subscribe(data => {
    this.sub1.next(data.data1);
    this.sub2.next(data.data2);
  });
}

// In your components

this.myService.obs1.subscribe(data1 => {});
this.myService.obs2.subscribe(data2 => {});

将http Response拆分为不同的Observable

3 个答案: