Ionic 2 – Geolocation & Google Maps

 WRITTEN BY GARETH DUNNE @JSDIARIES

One of the most straightforward ways to demonstrate Ionic Native and how it works is to use the GeoLocation native plugin. This will allow us to use a range of methods that will configure the the users current GeoLocation and we can then use this information in combination with a Google Maps implementation as well.

There is already some well established tutorials for achieving this so I’m going reference them in this post whilst also giving an overview for those that don’t have to time to implement their own example.

Please also keep in mind this excellent Ionic 2 book that will get you up to scratch very quickly.

And these articles by Toptal might help you to further understand Ionic concepts:

• Ionic 1 and 2 key differences.
• Common Ionic development mistakes

With your Ionic 2 project already created we need to install the cordova geolocation plugin here.

 ionic plugin add cordova-plugin-geolocation

This plugin will provide information about the current users device’s location, such as latitude and longitude. When starting the application, the user will receive a dialog asking for permission to use the current location.

This is a standard practice as some of the native plugins want to ensure that the user is content with sharing certain information with our Ionic 2 application.

In our created Ionic page, where we want to display our Google maps instance, we need to import our GeoLocation plugin from ionic native so we have access to it in the page.

 import { Geolocation } from '@ionic-native/geolocation';

We should then add an event click listener to the desired button that will provide the action of locating the users current position.

  
import { Geofence, Geolocation, SMS } from 'ionic-native'; 

export class GeoPage {
  location:any;
  constructor( private navCtrl: NavController) { }
   onLocateUser() {
    Geolocation.getCurrentPosition()
      .then(
      (location) => {
        console.log('Location successful')
        this.location.lat = location.coords.latitude;
        this.location.lng = location.coords.longitude;
      }
      )
  }
}

We are just invoking the .getCurrentPosition() method on the imported Geolocation object. Afterwards or .then(),  we assign the current value of our location variable to our components location variable of type any that was declared earlier in the component.

In our html file we are now able to output a value for our coordinates by accessing the properties for coordinates (.coords) and for the latitude value of those coordinates (.latitude) as well as the longitude (.longitude) on the location object.

 
    
      
        
Your Location: {{ location.coords.latitude  }}
       
        
      
    
     

While getting a GeoLocation is handy to know, what exactly should we do with the users position? Well you could implement the retrieved coordinates into a Google Maps implementation in your App.

There are two main ways to do this.

The first is to install Angular Google Maps. This is very well covered in the video tutorial below by Mindspace.

Fast forward to about 21:37.

And if you have the time,  be sure to watch part 1 and 2 in its entirety as you will come away with a full application with some nice Ionic Native functionality.

The second option that we can do is to use the JavaScript SDK, so that we can put in the header of our index.html file. This would be considered an easier way to implement it and it will also work in the browser as well as natively on devices .

However, for both cases you might as well generate an API key as if you were to ever to implement your app into a production environment or upload it to the app store there is a usage limit Google has and you might have to pay in order to remove the limit.

https://developers.google.com/maps/documentation/javascript/get-api-key

Without generating an API key, to use the Maps SDK simply put the following in your index.html file.

We then just need to reference the map id in our template HTML.

By default, the div containing our Google Maps object has no styling properties. We need to change this order for the map to display properly.

 
#map {
  width: 100%;
  height: 100%;
}  

Overall, I hope that this post has given a good indication of how to use Ionic Native plugins and from that point how to combine them together.

I didn’t want to provide too much detail as there is already quite a lot of fully fledged tutorials on this.

However, if you followed the links and references in the tutorial provided there is plenty of information to digest but bear in mind that the way you implement Ionic Native functionality never really changes, its just the built in methods and functions of the particular Ionic Native plugin that you are using that will be different.

I’m far from an expert in Ionic 2 but as I’m getting to grips it, I’m becoming more comfortable with Hybrid App development and want to share what I’m learning so be sure to check out our future posts on it.

I’m thinking about covering the changes in Ionic 3 and what it means for the framework.

Please check out our resources here for additional reading content.

A lot of this post stems from Josh Morony’s Ionic Google Maps & Geolocation guide so be sure to check his post out and his great Ionic 2 content in general.

Ionic 2: How to Use Google Maps & Geolocation