Combine requests in series - Angular 7

Combine requests in series - Angular 7

By : user2185424
Date : November 21 2020, 04:01 AM
I wish this helpful for you I'm trying to chain a few requests in a series, something like forkJoin but the requests NOT being requested in parallel. Here's what I have so far: , Here's what ended up working:
code :
import { toArray } from 'rxjs/operators';
import { concat } from 'rxjs';

let nodeDetails = this.http.get('node/1/')
let nodeParents = this.http.get('nodeParents/1/')
let nodeTree = this.http.get('nodeTree/1/')
let nodeUsers = this.http.get('nodeUsers/1/')
let nodeDocuments = this.http.get('nodeDocuments/1/')
const requests = concat(nodeDetails, nodeParents, nodeTree, nodeUsers, nodeDocuments)

    .subscribe(responses => {
        // Array of responses

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Angular 4. A series of http requests get cancelled

Angular 4. A series of http requests get cancelled

By : C.Lewis
Date : March 29 2020, 07:55 AM
wish of those help I've found a potential reason of this behavior.
to https://github.com/ghetolay and https://github.com/dklmuc
code :
for (let i = 1; i < 50; i++) {
    http.get(`https://swapi.co/api/people/${i}`).subscribe((result) => {
        console.log(i, result);
Angular 4 combine data from multiple HTTP requests

Angular 4 combine data from multiple HTTP requests

By : Sarvam Ariwala
Date : March 29 2020, 07:55 AM
Any of those help You can use the switchMap operator (alias of flatMap) in the following code :
code :
// Observables mocking the data returned by http.get()
const studentObs = Rx.Observable.from([
  {"ID" : 1 , "SchoolCode": "A150", "UserID": 1 }, 
  {"ID" : 5 , "SchoolCode": "A140" , "UserID": 4}, 
  {"ID" : 9 , "SchoolCode": "C140" , "UserID": 3}
const userObs = Rx.Observable.from([
  {"ID" : 1, "Name": "Rick" , "FamilyName": "Grimes" },
  {"ID" : 3, "Name": "Tom" , "FamilyName": "Cruise" },
  {"ID" : 4, "Name": "Amy" , "FamilyName": "Poehler" }
// Return an observable emitting only the given user.
function getUser(userID) {
  return userObs.filter(user => user.ID === userID);

  .switchMap(student => {
     return getUser(student.UserID).map(user => {
       // Merge the student and the user.
       return Object.assign(student, {user: user});
  .subscribe(val => console.log(val));
Angular combine data from multiple http requests

Angular combine data from multiple http requests

By : Paulyj87
Date : March 29 2020, 07:55 AM
it should still fix some issue If you want to ask for different products in parallel you can use forkJoin operator:
code :
getData(productIds: Array<string>): Observable<any> {  
  const data = productIds.map(element => {
     const path = this.serverUrl + '?' + 'productid=' + element;
     return this.httpClient.get(path);
  return forkJoin(...data);
Angular and RxJs combine two http requests

Angular and RxJs combine two http requests

By : Normalize
Date : March 29 2020, 07:55 AM
To fix the issue you can do Maybe forkJoin is the one you are looking for ?
forkJoin work best with Http call and I'm using it a lot when dealing with http request
code :
// RxJS v6.5+
import { ajax } from 'rxjs/ajax';
import { forkJoin } from 'rxjs';

  when all observables complete, provide the last
  emitted value from each as dictionary
  // as of RxJS 6.5+ we can use a dictionary of sources
    google: ajax.getJSON('https://api.github.com/users/google'),
    microsoft: ajax.getJSON('https://api.github.com/users/microsoft'),
    users: ajax.getJSON('https://api.github.com/users')
  // { google: object, microsoft: object, users: array }
Angular 8 make multiple http requests and combine all results

Angular 8 make multiple http requests and combine all results

By : loxeen
Date : March 29 2020, 07:55 AM
To fix the issue you can do your code is correct since that is the expected behavior of forkjoin you just need to map it a little bit
code :
forkJoin([res1, res2, res3, res4, res5])
.pipe(map(data => data.reduce((result,arr)=>[...result,...arr],[])))
.subscribe(data =>{

  this.autoCompleteValues = data;
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