agm-map dynamic display/updation of markers not working

Abhijath picture Abhijath · Jun 15, 2018 · Viewed 8.8k times · Source

I am using Angular Google Maps (https://angular-maps.com/) in an Angular 5 application, also using socket.io for polling of the latitude and longitudes from server. I'm able to push the data to an array in the component, but the agm-map isn't getting updated

component.ts

import { Component, OnInit } from '@angular/core';
import { SocketService } from '../../app/services/socket.service';

@Component({
  selector: 'app-maps',
  templateUrl: './maps.component.html',
  styleUrls: ['./maps.component.scss']
})
export class MapsComponent implements OnInit {

  public title: string = 'AGM project';
  public lat: number = 12.954517;
  public lng: number = 77.3507335;


  public msg : string;
  public mcar = 
  "https://maps.google.com/mapfiles/kml/shapes/parking_lot_maps.png";
  public agmMarkers: agmmarker[] = [
  {
    lat: 12.954517,
    lng: 77.3507335,
    icn: this.mcar
  }
 ];

 constructor(private socketService : SocketService) { }

ngOnInit() {
 this.socketService
    .getMessage()
    .subscribe((msg: any) => {
      console.log("msg: "+JSON.stringify(msg));
      this.updateMarkers(msg);
    });
}

public updateMarkers(msg){
 this.agmMarkers = [];
  for (let entry of msg.stats) {
    console.log("entry.latlng.lat: "+entry.latlng.lat); 
    console.log("entry.latlng.lng: "+entry.latlng.lng); 
    this.agmMarkers.push({
      lat: entry.latlng.lat,
      lng: entry.latlng.lng,
      icn: this.mcar
    });
  }
 }
}

interface agmmarker {
  lat?: number;
  lng?: number;
  icn?: string;
}

component.html

<agm-map [latitude]="lat" [longitude]="lng">
    <agm-marker *ngFor="let i of agmMarkers" 
      [latitude]="i.lat" [longitude]="i.lng" [iconUrl]="i.icn">
    </agm-marker>
</agm-map>

Answer

Abhijath picture Abhijath · Jun 15, 2018

My bad. The response from the service was in string format.

this.agmMarkers.push({
  lat: +entry.latlng.lat,
  lng: +entry.latlng.lng,
  icn: this.mcar
});

Typecasting latitude and longitude resolved the issue.