3

Hello I need to get some response after posting json object, using toPromise, its my code, respond is undefined:

export class ApiStorage{
constructor( @Inject(Http) private http: Http ){}
    rs(){
    this.http.post('http://0.0.0.0:80/student/outbound', this.json, headers)
            .toPromise()
            .then(response => {
                respond = JSON.stringify(response);
                return respond; //<- edited
            })
            .catch((error: any) => {
            ...
                });
    }
}

then when in main component I use 

send(){
    respondJSON = apistorage.rs();
    console.log(respondJSON);
    }

respondJSON is undefined

Jędrek Markowski
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    Possible duplicate of [How do I return the response from an asynchronous call?](https://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call) – eko Jul 05 '17 at 08:59

1 Answers1

6

respond will always be undefined in your code, because you are making an asynchronous call to a webservice, which you do not await before logging to console.

export class ApiStorage{

    constructor( @Inject(Http) private http: Http ){}

    rs() {

        return this.http.post('http://0.0.0.0:80/student/outbound', this.json, headers)
            .toPromise()
            .then(response => {
                let respond = JSON.stringify(response));
                return respond;
            })
            .catch((error: any) => {
                ...
            });
    }
}

// rs now returns a promise, which can be used like this
// inside another function
send() {
    apistorage.rs().then(res => {
        console.log(res);
    }
}
Hinrich
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  • But can you help me again and tell how to return respond? When I use respond = JSON.stringify(response)); return respond; // <- this returns nothing – Jędrek Markowski Jul 05 '17 at 09:47
  • Can you please post a new question for this and show some more of your code, so that we can see the context? Would be easier to help. – Hinrich Jul 05 '17 at 09:50
  • How do you call this function? Where should it return to? Can you also show some of that code, please? – Hinrich Jul 05 '17 at 09:55