angular2如何将回调方法从组件传递到类（typescript文件）

Question

I have a class called data.ts. In that i have a method which is called from various components. This method subscribes the data from another service. On the completion of subscribe event i want to process the data received from server and call the callback method of component who has invoked myFunction. Is that possible to do? something like below:

myFunction(callback: function) {
    otherService.getData().subscribe((res: Response) => {
        //do some processing of response
        caller.callback(processed_response)
    });
}

Answer 1

Should be more convenient return the Observable and then subscribe from the caller.

myFunction() : Observable<any>{
    return otherService.getData();
}

At the caller:

myFunction.subscribe((res: Response) => {
        //use the response
});

Answer 2

To elaborate Fals' question based on your comment (as you haven't gotten an updated answer).

You can use .map instead. You have probably mapped the response once earlier, but you can map several times.

 myFunction() : Observable<any>{
    return otherService.getData()
      .map(res => {
         return ... // your processing
      })
}

and then .subscribe :

myFunction.subscribe(data => {
   //do whatever you like
});