agm-map dynamic display/updation of markers not working

Question

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>

score 7 · Accepted Answer · answered Jun 15 '18 at 07:14

7

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.

answered Jun 15 '18 at 07:14

Abhijath

111
1
1
6

1

Yes, typecasting was the fix for me too. My object I was adding to agmMarkers had lat and lng being a number instead of a string. – Benjamin Castor Jul 23 '18 at 19:08
hey @Abhijath. is there any way to make a smooth transition for moving markers on a map? update with ngFor makes flash on the map. – Yash Majithiya Dec 06 '18 at 06:00

score 0 · Answer 2 · answered Sep 26 '18 at 09:39

I am using @agm/core": "^1.0.0-beta.2

   import { MapsAPILoader } from '@agm/core';



    export class JovenComponent implements OnInit
         { 

        constructor(public mapsApiLoader: MapsAPILoader) {}
        ngOnInit() {
                     //once you get data from the service this.joven=data
                    //here data is having all the information
                      this.mapsApiLoader.load().then(()=>{
                      this.lat=Number(this.joven.user_residential_address.latitude);
                      this.lng=Number(this.joven.user_residential_address.longitude);
                         })
                   }
          }

In HTML

<agm-map [latitude]="lat" [longitude]="lng" [zoom]="zoom" [disableDefaultUI]="true">
                      <agm-marker [latitude]="lat" [longitude]="lng">
                        <agm-info-window>
                          <strong>{{joven.name}}</strong>
                          <br/>
                          <strong>Cidade: {{joven?.user_residential_address?((joven?.user_residential_address?.city!==null)?joven?.user_residential_address?.city:'&mdash;'):'&mdash;'}}
                          </strong>
                          <br/>
                          <strong>Código de estado: {{joven?.user_residential_address?((joven?.user_residential_address?.stateCode!==null)?joven?.user_residential_address?.stateCode:'&mdash;'):'&mdash;'}}
                          </strong>
                          <br/>
                          <strong>CEP: {{joven?.user_residential_address?((joven?.user_residential_address?.zipcode!==null)?joven?.user_residential_address?.zipcode:'&mdash;'):'&mdash;'}}
                          </strong>
                        </agm-info-window>
                      </agm-marker>
                    </agm-map>

agm-map dynamic display/updation of markers not working

2 Answers2