How could I use a system.import() into component angular 2

问题

I saw in this post that you can use SystemJS to load external javascript files into my components in Angular 2.

In my index.html :

<script>
        System.config({
            packages: {
                "frontOfficeA2/src": {
                    format: 'register',
                    defaultExtension: 'js'
                },
                "angular2-jwt": {
                    "defaultExtension": "js"
                },
                "ng2-bootstrap": {
                    "defaultExtension": "js"
                },
                "system": {
                    "defaultExtension": "js"
                }
            },
            map: {
                "angular2-jwt": "lib/angular2-jwt",
                "ng2-bootstrap": "lib/ng2-bootstrap",
                "moment": 'lib/moment/moment.js',
                "system": 'lib/systemjs/dist/system.src.js'
            }
        });
        System.import('frontOfficeA2/src/app.js').then(null, console.error.bind(console));
    </script>

And my component :

import {Component} from 'angular2/core';
import { DATEPICKER_DIRECTIVES } from 'ng2-bootstrap/ng2-bootstrap';
import { System } from 'system';

@Component({
  selector: 'main',
  templateUrl: 'app/components/main/main.html',
  styleUrls: ['app/components/main/main.css'],
  providers: [],
  directives: [DATEPICKER_DIRECTIVES],
  pipes: []
})
export class Main {
    date: Date = new Date();
    constructor() {
        System.import('path/to/your/file').then(refToLoadedScript => {
            refToLoadedScript.someFunction();
        });
    }
}

Finally, when I start my app :

frontOfficeA2/src/app/components/main/main.ts(3,24): error TS2307: Cannot find module 'system'.

If somebody have an idea of what am I doing wrong .. :)

Thanks :)

回答1:

In fact, SystemJS is used under the hood when you import things. It's because you configured your TypeScript compiler to use it. See the tsconfig.json file:

{
  "compilerOptions": {
    "target": "ES5",
    "module": "system",  <---------------
    "moduleResolution": "node",
    "sourceMap": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "removeComments": false,
    "noImplicitAny": false
  },
  "exclude": [
    "node_modules"
  ]
}

If you have a look at compiled JS files (these JS files are actually executed in the browser), you will see this:

System.register(['angular2/platform/browser', 'angular2/http', './app.component'], function(exports_1) {
  var browser_1, http_1, app_component_1;
  return {
    setters:[
        function (browser_1_1) {
            browser_1 = browser_1_1;
        },
        function (http_1_1) {
            http_1 = http_1_1;
        },
        function (app_component_1_1) {
            app_component_1 = app_component_1_1;
        }],
    execute: function() {
        browser_1.bootstrap(app_component_1.AppComponent, [http_1.HTTP_PROVIDERS]).then(function (componentRef) {
            console.log(componentRef.injector);
        });
    }
  }
});

for a TypeScript file like this:

import {bootstrap} from 'angular2/platform/browser';
import {HTTP_PROVIDERS} from 'angular2/http';
import {AppComponent} from './app.component';

bootstrap(AppComponent, [ HTTP_PROVIDERS ]).then((componentRef) => {
  console.log(componentRef.injector);
});

来源：https://stackoverflow.com/questions/35898339/how-could-i-use-a-system-import-into-component-angular-2

标签

javascript

angular

ecmascript-6

systemjs