Angular2 $ http承诺与Promise.all（）

Question

I'm triying to implement a simple promise pattern in angular2. The idea is execute a block of code when the two promise get resolved.

The approach is with Promise.all() and passing there the promises in my service:

predict(data): Promise<any> {
    let headers    = new Headers({'Content-Type': 'application/json'});
    let dataString = JSON.stringify(data);

    return this.http
      .post(`${this.baseUrl}/predict`, dataString, headers)
      .toPromise()
      .then(
        (res: Response) => Promise.resolve(res.json())
      )
      .catch(
        (err) => Promise.reject(err)
      );
  } // predict

And the component controller:

promiseOne = this.apiservice.predict(titleToPredict);
promiseTwo = this.apiservice.predict(secondTitleToPredict);

Promise.all(promiseOne, promiseTwo)
   .then(data => console.log(data))
   .catch(err => console.log(err));

But TypeScript Returns me Supplied parameters do not match any signature of call target.

As i know, the methods are promises, so... i can't figure what is the problem.

Answer 1

Should be...

Promise.all([promiseOne, promiseTwo])

... as this method takes one argument - an Iterable (such as an Array).