CODEWITHSUNDEEP
angularobservable
Naveen Kumar
Naveen Kumar

Reputation: 177

Observables or Promise in angular2

This post method is using in angular2. In this ajax call , the post method is doesnt waiting for response. can any one say how to use observable for holding the asynchrouous in javascript until response receives .

this.http.post("http://jsonplaceholder.typicode.com/posts",body,options)
.map((res:Response) => res.json())
.subscribe(
    data => { console.log("data is",data)},
    err => console.error(err),
    () => console.log('done')
  );

Upvotes: 2

Views: 85

Answers (2)

Shai
Shai

Reputation: 3872

Lets say this is your code:

let myData = null;
this.http.post("http://jsonplaceholder.typicode.com/posts",body,options)
.map((res:Response) => res.json())
.subscribe(
    data => {
        myData = data;
        console.log("data is",data);
    },
    err => console.error(err),
    () => console.log('done')
  );

console.log("Log the data again", myData);

So as you well know, the second logging will log null since the Observable probably hasn't retrieved a result yet. What you should do is simply put all the code that depends upon the data being ready inside the subscribe result handler, like so:

let myData = null;
this.http.post("http://jsonplaceholder.typicode.com/posts",body,options)
.map((res:Response) => res.json())
.subscribe(
    data => {
        myData = data;
        console.log("data is",data);
        console.log("Log the data again", myData);  // <--
    },
    err => console.error(err),
    () => console.log('done')
  );

Upvotes: 0

G&#252;nter Z&#246;chbauer
G&#252;nter Z&#246;chbauer

Reputation: 657731

When the response arrives 

data => { console.log("data is",data)},

is executed.

If you want other or more code to be executed when Data arrives, then add this code inside { } (instead or in addition to console.log(...))

That's how async execution works and there is no other way.

Upvotes: 1

Related Questions