I have 3 observables that need to be chained together, with the result from the first one used in the other 2. They must run sequentially and each one should wait for the previous one to complete before starting. Is there a way to chain them without nesting?
public observable1(): Observable<Response> {
let headers = new Headers();
headers.append("Content-Range", "bytes */*");
let requestOptions = new RequestOptions({headers: headers});
return this.http.put(url, "", requestOptions);
}
public observable2(data1url): Observable<Response> {
let headers = new Headers();
headers.append("Content-Range", "bytes */*");
let requestOptions = new RequestOptions({headers: headers});
return this.http.put(data1url, "", requestOptions);
}
public observable3(data1url): Observable<Response> {
let headers = new Headers();
headers.append("Content-Range", "bytes */*");
let requestOptions = new RequestOptions({headers: headers});
return this.http.put(data1url, "", requestOptions);
}
I currently have them nested in order to chain them, but I am wondering if there is a way to achieve this without nesting them.
public doHttpProcess() {
return this.observable1().concatMap(result1 => {
return this.observable2(result1.json().data1)
.concatMap(result2 => {
return this.observable3(result1.json().data1);
});
});
}
Thank you for any assistance you can provide.