Ionic 2: How to call Provider function in Controller class - ionic2

Question

I have created new Cordova Plugin only on my machine. Then I added it to my project. It is working fine when I call that plugin. Now, I tried to make a structured caller for my plugin. I created a Provider for it, but the problem is I don't know how to call my plugin function from my Controller class. Below is my sample code.
Provider: my-service.ts
import { Injectable } from '#angular/core';
import { Http } from '#angular/http';
import 'rxjs/add/operator/map';
declare let myPlugin: any;
#Injectable()
export class MyService {
constructor(public http: Http) {
console.log('Hello MyService Provider');
}
public myFunction() {
myPlugin.myPluginFunction(
(data) => {
return data;
},
(err) => {
return err;
});
}
}
Pages: my-page.ts
import { Component } from '#angular/core';
import { NavController, ViewController } from 'ionic-angular';
import { MyService } from '../../providers/my-service';
#Component({
selector: 'page-my-page-ionic',
templateUrl: 'hello-ionic.html'
})
export class MyPage {
constructor(private viewCtrl: ViewController, private myService: MyService) {}
ionViewWillEnter() {
//I tried to call like this
this.myService.myFunction().subscribe(
data => {
alert("success");
},
error => {
alert("error");
});
}
}
It returns me this error - Property 'subscribe' does not exist on type 'void'. I don't know how to call that function, since my provider returns me success or error.

Answer 1

I think since your myFunction() does not return any observable you cannot subscribe to it. It just returns data directly.
You can use it like this in this case:
var data = this.myService.myFunction();
console.log("Data from plugin is :", data);
If you want to use it as an Observable, return a new observable like this:
public myFunction() {
return Observable.create(observer => {
myPlugin.myPluginFunction(
(data) => {
observer.next(data);
},
(err) => {
observer.next(data);
});
},
(err) => {
observer.error(err);
});
}