问题
I am doing some http requests and use rxjs for successfull notification of the result:
getReportings(departmentId: number): Observable<any> {
return Observable.forkJoin(
this.http.get('/api/members/' + departmentId).map(res => res.json()),
this.http.get('/api/reports/' + departmentId).map(res => res.json())
);
}
When both http requests are done I want inside the getReportings method to iterate the reports array , read some values and for each report make again a new http request with those values.
All in all I have 2 (member/reports) + appr. 4 to 8 (other stuff) requests.
When all appr. 6 to 8 requests are done I want to get ALL data from the previous 6 to 8 requests in the successfull handler.
How can I do this with rxjs?
UPDATE
As user olsn asked for more details and I understand him now whats his concern I put more data here (pseudo code) how the 6 to 8 requests should look like:
getReportings(departmentId: number): Observable<any> {
return Observable.forkJoin(
this.http.get('/api/members/' + departmentId).map(res => res.json()),
this.http.get('/api/reports/' + departmentId).map(res => res.json())
).switchMap((result: [any[], any[]]) => {
let members: any[] = result[0];
let reports: any[] = result[1];
let allNewStreams: Observable<any>[] = [
Observable.of(members),
Observable.of(reports)
];
for(let report of reports)
{
allNewStreams.push(
this.http.get(report.url + ?key1=report.name1?).map(res => res.json()));
}
return Observable.forkJoin(allNewStreams); // will contain members, reports + 4-6 other results in an array [members[], reports[], ...other stuff]
});
}
回答1:
You could extend your stream using switchMap
, like this:
getReportings(departmentId: number): Observable<any> {
return Observable.forkJoin(
this.http.get('/api/members/' + departmentId).map(res => res.json()),
this.http.get('/api/reports/' + departmentId).map(res => res.json())
).switchMap((result: [any[], any[]]) => {
let members: any[] = result[0];
let reports: any[] = result[1];
let allNewStreams: Observable<any>[] = [
Observable.of(members),
Observable.of(reports)
];
// do your stuff and push new streams to array...
if (foo) { // for each additional request
let reportId: string | number = reports[0].id; // or however you retrieve the reportId
allNewStreams.push(
this.http.get('some/api/ + bar)
.map(res => res.json())
.map(data => ({reportId, data})); // so your final object will look like this: {reportId: "d38f68989af87d987f8", data: {...}}
);
}
return Observable.forkJoin(allNewStreams); // will contain members, reports + 4-6 other results in an array [members[], reports[], ...other stuff]
});
}
This should do it, it's more like an "old-style-logic-hammer" approach - in case you are looking for it: There might be a more elegant way to solve this by using other operators, but that is hard to say without knowing the full data and all logic.
来源:https://stackoverflow.com/questions/41204055/rxjs-with-multiple-forkjoin-when-doing-http-requests