I wanna do a simple pet project. The idea is to build a mobile application. This application will track my gps location and send this information to a Firebase database. I've never play with Firebase and I want to learn a little bit. With this information I will build a simple web application hosted in my Raspberry Pi. This web application will show a Google map with my last location. I will put this web application in my TV and anyone in my house will see where I am every time.
That's the idea. I want a MVP. First the mobile application. I will use ionic framework. The mobile application is very simple it only has a toggle to activate-deactivate the background geolocation (sometimes I don't want to be tracked :).
<ion-header>
<ion-navbar>
<ion-title>
Ionic Blank
</ion-title>
</ion-navbar>
</ion-header>
<ion-header>
<ion-toolbar [color]="toolbarColor">
<ion-title>{{title}}</ion-title>
<ion-buttons end>
<ion-toggle color="light"
checked="{{isBgEnabled}}"
(ionChange)="changeWorkingStatus($event)">
</ion-toggle>
</ion-buttons>
</ion-toolbar>
</ion-header>
<ion-content padding>
</ion-content>And the controller:
import {Component} from '@angular/core';
import {Platform} from 'ionic-angular';
import {LocationTracker} from "../../providers/location-tracker/location-tracker";
@Component({
selector: 'page-home',
templateUrl: 'home.html'
})
export class HomePage {
public status: string = localStorage.getItem('status') || "-";
public title: string = "";
public isBgEnabled: boolean = false;
public toolbarColor: string;
constructor(platform: Platform,
public locationTracker: LocationTracker) {
platform.ready().then(() => {
if (localStorage.getItem('isBgEnabled') === 'on') {
this.isBgEnabled = true;
this.title = "Working ...";
this.toolbarColor = 'secondary';
} else {
this.isBgEnabled = false;
this.title = "Idle";
this.toolbarColor = 'light';
}
});
}
public changeWorkingStatus(event) {
if (event.checked) {
localStorage.setItem('isBgEnabled', "on");
this.title = "Working ...";
this.toolbarColor = 'secondary';
this.locationTracker.startTracking();
} else {
localStorage.setItem('isBgEnabled', "off");
this.title = "Idle";
this.toolbarColor = 'light';
this.locationTracker.stopTracking();
}
}
}As you can see, the toggle button will activate-deactivate the background geolocation and it also changes de background color of the toolbar.
For background geolocation I will use one cordova plugin available as ionic native plugin: https://ionicframework.com/docs/native/background-geolocation/
Here you can see read a very nice article explaining how to use the plugin with ionic: https://www.joshmorony.com/adding-background-geolocation-to-an-ionic-2-application/
As the article explains I've created a provider
import {Injectable, NgZone} from '@angular/core';
import {BackgroundGeolocation} from '@ionic-native/background-geolocation';
import {CONF} from "../conf/conf";
@Injectable()
export class LocationTracker {
constructor(public zone: NgZone,
private backgroundGeolocation: BackgroundGeolocation) {
}
showAppSettings() {
return this.backgroundGeolocation.showAppSettings();
}
startTracking() {
this.startBackgroundGeolocation();
}
stopTracking() {
this.backgroundGeolocation.stop();
}
private startBackgroundGeolocation() {
this.backgroundGeolocation.configure(CONF.BG_GPS);
this.backgroundGeolocation.start();
}
}The idea of the plugin is send a POST request to a url with the gps data in the body of the request. So, I will create a web api server to handle this request. I will use my Raspberry Pi3 (one of mines :) to serve the application. I will create a simple PHP/Lumen application. This application will handle the POST request of the mobile application and also will serve a html page with the map (using google maps).
Mobile requests will be authenticated with a token in the header and web application will use a basic http authentication. Because of that I will create two middlewares to handle the the different ways to authenticate.
<?php
require __DIR__ . '/../vendor/autoload.php';
use App\Http\Middleware;
use App\Model\Gps;
use Illuminate\Contracts\Debug\ExceptionHandler;
use Illuminate\Http\Request;
use Laravel\Lumen\Application;
use Laravel\Lumen\Routing\Router;
(new Dotenv\Dotenv(__DIR__ . '/../env/'))->load();
$app = new Application(__DIR__ . '/..');
$app->singleton(ExceptionHandler::class, App\Exceptions\Handler::class);
$app->routeMiddleware([
'auth' => Middleware\AuthMiddleware::class,
'basic' => Middleware\BasicAuthMiddleware::class,
]);
$app->router->group(['middleware' => 'auth', 'prefix' => '/locator'], function (Router $route) {
$route->post('/gps', function (Gps $gps, Request $request) {
$requestData = $request->all();
foreach ($requestData as $poi) {
$gps->persistsData([
'date' => date('YmdHis'),
'serverTime' => time(),
'time' => $poi['time'],
'latitude' => $poi['latitude'],
'longitude' => $poi['longitude'],
'accuracy' => $poi['accuracy'],
'speed' => $poi['speed'],
'altitude' => $poi['altitude'],
'locationProvider' => $poi['locationProvider'],
]);
}
return 'OK';
});
});
return $app;As we can see the route /locator/gps will handle the post request. I've created a model to persists gps data in the firebase database:
<?php
namespace App\Model;
use Kreait\Firebase\Factory;
use Kreait\Firebase\ServiceAccount;
class Gps
{
private $database;
private const FIREBASE_CONF = __DIR__ . '/../../conf/firebase.json';
public function __construct()
{
$serviceAccount = ServiceAccount::fromJsonFile(self::FIREBASE_CONF);
$firebase = (new Factory)
->withServiceAccount($serviceAccount)
->create();
$this->database = $firebase->getDatabase();
}
public function getLast()
{
$value = $this->database->getReference('gps/poi')
->orderByKey()
->limitToLast(1)
->getValue();
$out = array_values($value)[0];
$out['formatedDate'] = \DateTimeImmutable::createFromFormat('YmdHis', $out['date'])->format('d/m/Y H:i:s');
return $out;
}
public function persistsData(array $data)
{
return $this->database
->getReference('gps/poi')
->push($data);
}
}The project is almost finished. Now we only need to create the google map.
That's the api
<?php
$app->router->group(['middleware' => 'basic', 'prefix' => '/map'], function (Router $route) {
$route->get('/', function (Gps $gps) {
return view("index", $gps->getLast());
});
$route->get('/last', function (Gps $gps) {
return $gps->getLast();
});
});And the HTML
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
<meta charset="utf-8">
<title>Locator</title>
<style>
#map {
height: 100%;
}
html, body {
height: 100%;
margin: 0;
padding: 0;
}
</style>
</head>
<body>
<div id="map"></div>
<script>
var lastDate;
var DELAY = 60;
function drawMap(lat, long, text) {
var CENTER = {lat: lat, lng: long};
var contentString = '<div id="content">' + text + '</div>';
var infowindow = new google.maps.InfoWindow({
content: contentString
});
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 11,
center: CENTER,
disableDefaultUI: true
});
var marker = new google.maps.Marker({
position: CENTER,
map: map
});
var trafficLayer = new google.maps.TrafficLayer();
trafficLayer.setMap(map);
infowindow.open(map, marker);
}
function initMap() {
lastDate = '{{ $formatedDate }}';
drawMap({{ $latitude }}, {{ $longitude }}, lastDate);
}
setInterval(function () {
fetch('/map/last', {credentials: "same-origin"}).then(function (response) {
response.json().then(function (data) {
if (lastDate !== data.formatedDate) {
drawMap(data.latitude, data.longitude, data.formatedDate);
}
});
});
}, DELAY * 1000);
</script>
<script async defer src="https://maps.googleapis.com/maps/api/js?key=my_google_maps_key&callback=initMap">
</script>
</body>
</html>And that's all just enough for a weekend.
