Angular 2 - import of external leaflet typescript library

问题

Im trying to import the a typescript leaflet library into my angular 2 application.

This is my map component. Ive installed leaflet.d.ts with tsd install and my application does not complain about /// <reference path="../../typings/leaflet/leaflet.d.ts"/> but when i try to use a L.map which is a exported module in leaflet.d.ts i get the error "ReferenceError: L is not defined". This is the first time i try to import a external typescript library in angular 2 and clearly im doing something wrong.

/// <reference path="../../typings/leaflet/leaflet.d.ts"/>
import { Component } from 'angular2/core';
@Component({
  selector: 'map',
  template: `
        <div id="map"></div>
  `,
})
export class Map{
    constructor(){
          var map = new L.Map('map', {
             zoomControl: false
         });
    }

package.json

{
  "dependencies": {
    "angular2": "^2.0.0-beta.3",
    "es6-promise": "^3.0.2",
    "es6-shim": "^0.33.3",
    "normalize.css": "^3.0.3",
    "reflect-metadata": "0.1.2",
    "rxjs": "5.0.0-beta.2",
    "systemjs": "0.19.6",
    "typings": "^0.6.4",
    "zone.js": "^0.5.11"
  },
  "devDependencies": {
    "concurrently": "^1.0.0",
    "gh-pages": "^0.11.0",
    "grunt": "~0.4.5",
    "grunt-contrib-clean": "^1.0.0",
    "grunt-contrib-copy": "^1.0.0",
    "grunt-contrib-cssmin": "^1.0.0",
    "grunt-contrib-nodeunit": "~0.4.1",
    "grunt-contrib-sass": "~0.9.0",
    "grunt-contrib-uglify": "~0.5.0",
    "grunt-shell": "^1.2.1",
    "lite-server": "^2.0.1",
    "normalize.css": "^3.0.3",
    "typescript": "^1.7.5"
  },
  "scripts": {
    "publish": "node publish.js",
    "tsc": "tsc",
    "tsc:w": "tsc -w",
    "lite": "lite-server",
    "start": "concurrent \"npm run tsc:w\" \"npm run lite\" "
  }
}

tsd.json

{
  "version": "v4",
  "repo": "borisyankov/DefinitelyTyped",
  "ref": "master",
  "path": "typings",
  "bundle": "typings/tsd.d.ts",
  "installed": {
    "leaflet/leaflet.d.ts": {
      "commit": "1da639a106527e0c4010b354a1efe52a3059a291"
    }
  }
}

Could anyone tell me what I am doing wrong?

Thanks!

回答1:

You need to include the leaflet JS file:

System.config({
  map: {
    leaflet: 'https://cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.7/leaflet.js'
  },
  packages: {'app': {defaultExtension: 'ts'}} 
});
System.import('app/main')
        .then(null, console.error.bind(console));

Then you can import it in your modules this way:

import {Component, OnInit} from 'angular2/core';
import leaflet from 'leaflet';

See this plunkr: http://plnkr.co/edit/aUo2uvlxC5ji32u01jfF?p=preview.

回答2:

I can suggest you a workaround until angular-cli get better support for 3rd party libs. It worked for me :)

First go to the project directory and type

npm install leaflet --save

then open your angular-cli-build.js and add this line

vendorNpmFiles: [
   ..................
   'leaflet/**/*.js',
    ....................
  ]

now open your src/system-config.ts, write

const map:any ={
     ..................
   'leaflet': 'vendor/leaflet/dist',
    ....................

}

and

const packages: any = {
  'leaflet': {
    format: 'cjs'
  }

};

Open your src/index.html, add this

 <script type="text/javascript" src="vendor/leaflet/dist/leaflet.js"></script>

and dont forget to add the css file also

  <link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet/v0.7.7/leaflet.css" />

Now open your component where you want to use Leaflet

declare let L: any;
@Component({
  moduleId: module.id,
  selector: 'app-map',
  templateUrl: 'map.component.html',
  styleUrls: ['map.component.css']
})
export class MapComponent implements OnInit, AfterViewInit {
 leafletMap: any;
 ngAfterViewInit() {
    this.leafletMap = L.map("map").setView([23.709921, 90.407143], 7);
 }
}

Tada!! your map loaded :D

回答3:

I had to make some changes to get Thierry Templier's answer to work using systemjs and Angular 2.4.

I added Leaflet to my system.config.js file just as he states, but in my component I I had to import it this way:

import * as L from 'leaflet';

and then the L class was recognized in my MapComponent

export class MapComponent {
    let map = L.map("map").setView([38, -77], 13);
            L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
            attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
            }).addTo(map);
    }

回答4:

Meanwhile, everything you have to do is calling

npm install @types/leaflet@latest --save

and including the source in index.html.

No other imports or declarations needed. Then, the import could look like

import {control, LatLng, layerGroup, LayerGroup, Map} from "leaflet";

Also, map initialization should happen in ngOnInit(), constructor usage is not meant for logic.

来源：https://stackoverflow.com/questions/36375749/angular-2-import-of-external-leaflet-typescript-library