cordova-plugin-geolocation watchPosition() method

问题:

I'm working on a Ionic2-Angular2-Typescript application. I'm trying to use Cordova's Geolocation plugin, but when I call watchPosition method like in http://ionicframework.com/docs/v2/native/geolocation/ editor shows me some errors:

Error TS2339: Property 'code' does not exist on type 'Geoposition | PositionError'.

Error TS2339: Property 'coords' does not exist on type 'Geoposition | PositionError'.

This is my code:

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import 'rxjs';
import { Observable } from 'rxjs/Observable';
import { Geolocation, PositionError, Geoposition } from 'ionic-native';

export class LocationProvider {

    constructor(private http: Http) {}

    var subscription = Geolocation.watchPosition()
                          .filter((p) => p.code === undefined) //Filter Out Errors
                          .subscribe(position => {
  console.log(position.coords.longitude + ' ' + position.coords.latitude);
});
}

回答1:

Finally, I solved my problem as follows:

this.subscription = Geolocation.watchPosition().subscribe(position => {
    if ((position as Geoposition).coords != undefined) {
      var geoposition = (position as Geoposition);
      console.log('Latitude: ' + geoposition.coords.latitude + ' - Longitude: ' + geoposition.coords.longitude);
    } else { 
      var positionError = (position as PositionError);
      console.log('Error ' + positionError.code + ': ' + positionError.message);
    }
});

回答2:

How about just setting a type inside the callback functions? Makes for a shorter code if you're not interested in the errors anyway.

Something like this (not tested):

this.subscription = Geolocation.watchPosition()
    .filter((p: any) => p['code'] === undefined) // Filter Out Errors
    .subscribe((position: GeoPosition) => {
        console.log(position.coords.longitude + ' ' + position.coords.latitude);
    });