Moving Marker In Map Using SignalR in ng-map In AngularJS

In this article, I would like to know you about using of SignalR in ng-map In AngularJS.

So , To view map in the application, we have to add the angular script of ng-map and also to use SignalR, we have to add angular-signalr-hub from nuget package manager.

This angular-signalr-hub establish the connection from client to server and having some predefined properties like setting the rootpath and can write user defined listeners and methods that can establish the connection and stop the connection.

And also jquery.signalR-2.2.0.min.js is also added along with that, so that it can work with web sockets and connects the client with server and if any connection dropout happens, or any connection problems, it throws error message every second.

To create this application we need two projects in one solution, one is client side project i.e., in angularjs and the other is server side project i.e., webapi.

Create the empty project and add index.html and index.js files as follows for angularjs application

index.html :-

<!DOCTYPE html>

<html>

<head>

<title>AngularJS - Google Maps</title>

<!—To use google map we have to use below script -->

<!—To use SignalR in Angularjs -->

<!—To support working in SignalR, this JQuery SignalR should be used -->

</head>

<body>

<ng-map center="{{maplocation.center}}" style="height: 700px"

zoom="{{maplocation.zoom}}" mapTypeId="ROADMAP"

map-type-control="false">

<!--<shape name="polyline" path="{{maplocation.positions}}"

geodesic="true"

stroke-color="#FF0000"

stroke-opacity="1.0"

stroke-weight="2">

</shape>-->

<info-window id="info">

Device: {{maplocation.deviceId}}<br />

</div>

</info-window>

</ng-map>

</div>

<div>

</div>

</body>

</html>

index.js

var locapp = angular.module('angulargooglemaplocationtrackApp', ['ngMap','SignalR']);

locapp.controller('locationtrackerCtrl', ['$scope', '$http', 'Hub', 'NgMap', function ($scope, $http, Hub, NgMap) {

var serviceBasePath = 'http://localhost:58171';

var maplocation = this;

NgMap.getMap().then(function (map) {

maplocation.map = map;

});

//To load the Maps JavaScript API, use a script tag having Google API Key

maplocation.googleMapsUrl = "https://maps.googleapis.com/maps/api/js?key=AIzaSyC7QgeORUjgqSFlvmr9kT2mh8beqqB4buw";

maplocation.startPoint = "";

maplocation.devicePoint = "";

maplocation.positions = [];

maplocation.data = []

maplocation.center = "23.4440644, 79.0486879";

maplocation.zoom = 4;

var devId = "";

maplocation.drawMap = function () {

i = 1;

maplocation.devicePoint = "";

console.log(maplocation.deviceId);

if (devId) {

hub.removeDeviceFromGroup(devId);

}

hub.addDeviceToGroup(maplocation.deviceId);

devId = maplocation.deviceId;

$http.get(serviceBasePath + '/api/LocationTracker/ChangeDeviceLocations', {

params: { deviceId: maplocation.deviceId }

}).then(

function (response) {

}, function (error) {

//console.log(error);

});

}

var i = 1;

//Hub setup

var hub = new Hub('LocationTrackHub', {

listeners: {

'getDeviceLocation': function (lat, lng) {

var position = "[" + lat + "," + lng + "]";

maplocation.devicePoint = position;

// maplocation.positions.push(position);

if (i == 1) {

maplocation.zoom = 4;

maplocation.center = position;

i++;

}

$scope.$apply();

}

rootPath: serviceBasePath + '/signalr',

methods: ['addDeviceToGroup', 'removeDeviceFromGroup'],

errorHandler: function (error) {

console.error(error);

}

});

}]);

And now add another WebAPI project to the solution and install Microsoft.AspNet.SignalR.Core and Microsoft.AspNet.SignalR.SystemWeb

And add a folder named Hubs and add a .cs file named HubAction.cs to synchronize and send messages to the client side,for that implement Listeners using SignalR HubContext for continous interaction between the client side and server side application as below:

HubAction.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

namespace WebApi_ngMapSignalRHub.Hubs

{

public class HubActions

{

private static Microsoft.AspNet.SignalR.IHubContext GetDeviceHub()

{

return Microsoft.AspNet.SignalR.GlobalHost.ConnectionManager.GetHubContext<LocationTrackHub>();

}

public static void SendLocationUpdate(string DeviceId, double latitude, double longitude)

{

GetDeviceHub().Clients.Group(DeviceId).getDeviceLocation(latitude, longitude);

}

And add another .cs file to implement the hub to connect and disconnect or start and stop the connection through websocket to client side application as below :

LocationTrackHub.cs

using Microsoft.AspNet.SignalR;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

using System.Web;

namespace WebApi_ngMapSignalRHub.Hubs

{

public class LocationTrackHub :Hub

{

public override Task OnConnected()

{

Clients.Caller.hello("Hello!");

return base.OnConnected();

}

public void addDeviceToGroup(string deviceid)

{

Groups.Add(Context.ConnectionId, deviceid);

}

public void removeDeviceFromGroup(string deviceid)

{

Groups.Remove(Context.ConnectionId, deviceid);

}

And to access the locations from an API, for that add DeviceTrackerController and write the logic to get the saved locations or static locations. The code is as below:

DeviceTrackerController.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Net.Http;

using System.Threading;

using System.Web.Http;

using WebApi_ngMapSignalRHub.Hubs;

namespace WebApi_ngMapSignalRHub.Controllers

{

public class DeviceTrackerController : ApiController

{

[Route("api/DeviceTracker/ChangeDeviceLocations")]

[HttpGet]

public void ChangeDeviceLocations()

{

LocationDetailList locLst = new LocationDetailList();

var locList = locLst.LocationList;

foreach (var item in locList)

{

HubActions.SendLocationUpdate(item.DeviceId, item.Latitude, item.Longitude);

Thread.Sleep(5000);

}

// Class LocationDetails

public class LocationDetails

{

public string DeviceId { get; set; }

public double Latitude { get; set; }

public double Longitude { get; set; }

}

// The Below class is having property named 'LocationList' with get; set; accessors

public class LocationDetailList

{

// To get data from list

public List<LocationDetails> LocationList

{

get { return locationList; }

}

// Binding data to List i.e., set data to list

List<LocationDetails> locationList = new List<LocationDetails>()

{

new LocationDetails() {

DeviceId ="1001",

Latitude =17.4246285829186,

Longitude =78.3438836269752

new LocationDetails() {

DeviceId ="1001",

Latitude =17.52462858246374,

Longitude =78.4438836285764

new LocationDetails() {

DeviceId ="1001",

Latitude =17.62462858285758,

Longitude =78.5438836205945

new LocationDetails() {

DeviceId ="1001",

Latitude =17.72462858854758,

Longitude =78.6438836636475

new LocationDetails() {

DeviceId ="1001",

Latitude =17.82462857656475,

Longitude =78.7438836756667

new LocationDetails() {

DeviceId ="1001",

Latitude =18.4246285829186,

Longitude =79.3438836269752

new LocationDetails() {

DeviceId ="1002",

Latitude =23.4440644,

Longitude =79.0486879

new LocationDetails() {

DeviceId ="1001",

Latitude =19.4246285829186,

Longitude =80.3438836269752

new LocationDetails() {

DeviceId ="1002",

Latitude =24.4440644,

Longitude =80.0486879

};

}

While trying to hit Client Project to Server Project then, we will get CORS error, to rectify the CORS (Cross Origin Request Sharing) error, add reference Microsoft.AspNet.WebApi.Cors and add the below code in Register method In WebApiConfig file

var cors = new EnableCorsAttribute("*", "*", "*");

config.EnableCors(cors);

Now Run the application

Output :

After running the application it looks as below :

Enter the Device id in the search box as below :

Now Click on Show Tracks, now the output will be as below :

Download Code From GitHub

KODING ATTITUDE

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Friday 14 September 2018