Click Below to subscribe

How To Integrate Leaflet Maps in Angular 2022

Leaflet is an open-source JavaScript library for mobile-friendly interactive maps. In this tutorial, we will integrate leaflet maps in angular using ngx-leaflet package.

1. Let's install @angular/cli package.

npm install -g @angular/cli

 2. Create a new angular project.

ng new angular-leaflet-maps
cd angular-leaflet-maps

3. Install leaflet, @asymmetrik/ngx-leaflet packages inside the project.

npm install leaflet @asymmetrik/ngx-leaflet

Supported Versions:-

Angular    @asymmetrik/ngx-leaflet          command
  14              14               npm i @asymmetrik/ngx-leaflet
  13              13               npm i @asymmetrik/ngx-leaflet@13
  10              8                npm i @asymmetrik/ngx-leaflet@8
  9               7                npm i @asymmetrik/ngx-leaflet@7      

Checkout:- https://github.com/Asymmetrik/ngx-leaflet/blob/HEAD/CHANGES.md

4. Install @types/leaflet package.

npm install --save-dev @types/leaflet

5. Open src/styles.css and import leaflet.css

@import "~leaflet/dist/leaflet.css";

6. Open app.module.ts and import LeafletModule

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { LeafletModule } from '@asymmetrik/ngx-leaflet';

import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    LeafletModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

7. Open angular.json and update assets.

...
"architect": {
    "build": {
      "builder": "@angular-devkit/build-angular:browser",
      "options": {
        "outputPath": "dist/angular-leaflet-maps",
        "index": "src/index.html",
        "main": "src/main.ts",
        "polyfills": "src/polyfills.ts",
        "tsConfig": "tsconfig.app.json",
        "assets": [
          "src/favicon.ico",
          "src/assets",
          {
            "glob": "**/*",
            "input": "./node_modules/leaflet/dist/images",
            "output": "assets/"
          }
        ],

this object

{
    "glob": "**/*",
    "input": "./node_modules/leaflet/dist/images",
    "output": "assets/"
}

8. Open app.component.ts and add the following code.

import { Component } from '@angular/core';
import * as Leaflet from 'leaflet'; 

Leaflet.Icon.Default.imagePath = 'assets/';
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  map!: Leaflet.Map;
  markers: Leaflet.Marker[] = [];
  options = {
    layers: [
      Leaflet.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
        attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a>'
      })
    ],
    zoom: 16,
    center: { lat: 28.626137, lng: 79.821603 }
  }

  initMarkers() {
    const initialMarkers = [
      {
        position: { lat: 28.625485, lng: 79.821091 },
        draggable: true
      },
      {
        position: { lat: 28.625293, lng: 79.817926 },
        draggable: false
      },
      {
        position: { lat: 28.625182, lng: 79.81464 },
        draggable: true
      }
    ];
    for (let index = 0; index < initialMarkers.length; index++) {
      const data = initialMarkers[index];
      const marker = this.generateMarker(data, index);
      marker.addTo(this.map).bindPopup(`<b>${data.position.lat},  ${data.position.lng}</b>`);
      this.map.panTo(data.position);
      this.markers.push(marker)
    }
  }

  generateMarker(data: any, index: number) {
    return Leaflet.marker(data.position, { draggable: data.draggable })
      .on('click', (event) => this.markerClicked(event, index))
      .on('dragend', (event) => this.markerDragEnd(event, index));
  }

  onMapReady($event: Leaflet.Map) {
    this.map = $event;
    this.initMarkers();
  }

  mapClicked($event: any) {
    console.log($event.latlng.lat, $event.latlng.lng);
  }

  markerClicked($event: any, index: number) {
    console.log($event.latlng.lat, $event.latlng.lng);
  }

  markerDragEnd($event: any, index: number) {
    console.log($event.target.getLatLng());
  } 
}

Note:- you can also use mergeOptions() method instead of imagePath property.

LeafLet.Icon.Default.mergeOptions({
  iconRetinaUrl: 'assets/marker-icon-2x.png',
  iconUrl: 'assets/marker-icon.png',
  shadowUrl: 'assets/marker-shadow.png'
});

In the above code, you also use custom icons.

9. Open app.component.html and add the following code.

<div class="map-container"
  leaflet
  [leafletOptions]="options"
  (leafletMapReady)="onMapReady($event)"
  (leafletClick)="mapClicked($event)">
</div>

10. Open styles.css  file and add this css.

.map-container {
  height: 400px;
}

#Add a marker

const data = {
  position: { lat: 28.625043, lng: 79.810135 },
  draggable: true
}
const marker = this.generateMarker(data, this.markers.length - 1);
marker.addTo(this.map).bindPopup(`<b>${data.position.lat},  ${data.position.lng}</b>`);
this.markers.push(marker);

#Remove a marker

this.map.removeLayer(this.markers[index])
this.markers.splice(index, 1)

#Update a marker

this.markers[index].setLatLng({ lat: 28.625043, lng: 79.810135 });

getIcon() - get marker icon

getLatLng() - get marker position

setIcon() - set marker icon

setLatLng() - set marker position

setOpacity(opacity) - set marker opacity

11. Finally run the project.

ng serve --o

it will open http://localhost:4200 in the browser.

Extras:- Reverse Geocoding

12. Install leaflet-control-geocoder npm package.

npm i leaflet-control-geocoder

13. Import leaflet-control-geocoder

import { Component } from '@angular/core';
import * as Leaflet from 'leaflet';
import "leaflet-control-geocoder";

14. Create a function.

getAddress(lat: number, lng: number) {
  const geocoder = (Leaflet.Control as any).Geocoder.nominatim();
  return new Promise((resolve, reject) => {
      geocoder.reverse(
          { lat, lng },
          this.options.zoom,
          (results: any) => results.length ? resolve(results[0].name) : reject(null)
      );
  })
}

You can use this function by passing lat and lng.

async mapClicked($event: any) {
  console.log($event.latlng.lat, $event.latlng.lng);
  const address = await this.getAddress($event.latlng.lat, $event.latlng.lng);
  console.log(address)
}

Checkout my full angular-leaflet-maps example.

https://github.com/ultimateakash/angular-leaflet-maps

If you facing any issues. don't hesitate to comment below.

Thanks.

Leave Your Comment