我如何等待9 HTTP GET request Angular 2

Question

I have the next problem: I am doing a Plugin for Jenkins using its API REST. I want to get all the results of all builds and do the average fails/nºexec for each Job. I want to get the last 10 builds, so I have to send 10 http get. Actually my code is this:

for (var j = init; j >= 1; j--){
    this.http.get(data2.builds[j].url + this.finalURL).subscribe(response => {
        let data3 = response.json();
        if(data3.result == "FAILURE"){
            numberOfFails = numberOfFails+1;
        }
    }, error => console.error(error));
}
this.http.get(data2.builds[0].url + this.finalURL).subscribe(response => {
    let data3 = response.json();
    if (data3.result == "FAILURE"){
        numberOfFails = numberOfFails + 1;
    }
    let average = numberOfFails/(init+1);
    console.log(numberOfFails +" " + init+1 + " " +average);
    if (average <= 0.1){
        this.successList.push(new Job(data3.fullDisplayName, data3.result,data2.url, average));
    } else if (average<0.8){
        this.brokenList.push(new Job(data3.fullDisplayName, data3.result, data2.url, average));
    }else {
        this.failureList.push(new Job (data3.fullDisplayName, data3.result, data2.url, average));
    }

I do 9 HTTP request looking for the result. After I do the last request looking for the result and I do the average. Sometimes the average is done before the 9 previous request finish. How can I fix this?

Answer 1

You can use Observable.zip or Observable.forkJoin to resolve them all at once, and get the results at once.. this is similar to Promise.all. I would personally use forkJoin in this case http://xgrommx.github.io/rx-book/content/observable/observable_methods/forkjoin.html

var source = Rx.Observable.forkJoin(
  Rx.Observable.return(42),
  Rx.Observable.range(0, 10),
  Rx.Observable.from([1,2,3]),
  RSVP.Promise.resolve(56)
 //Your http calls will be here instead
);

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
    console.log('Completed');
  });

// => Next: [42, 9, 3, 56]