我有这个模块,它将外部库与额外的逻辑组件化,而不直接将<script>标记添加到index.html中:

import 'http://external.com/path/file.js'
//import '../js/file.js'

@Component({
    selector: 'my-app',
    template: `
        <script src="http://iknow.com/this/does/not/work/either/file.js"></script>
        <div>Template</div>`
})
export class MyAppComponent {...}

我注意到ES6规范的导入是静态的,并且是在TypeScript编译期间解析的,而不是在运行时。

总之,让它变得可配置,这样file。js就会从CDN或本地文件夹加载? 如何告诉Angular 2动态加载脚本?


当前回答

您可以像这样在组件中动态加载多个脚本。ts文件:

 loadScripts() {
    const dynamicScripts = [
     'https://platform.twitter.com/widgets.js',
     '../../../assets/js/dummyjs.min.js'
    ];
    for (let i = 0; i < dynamicScripts.length; i++) {
      const node = document.createElement('script');
      node.src = dynamicScripts[i];
      node.type = 'text/javascript';
      node.async = false;
      node.charset = 'utf-8';
      document.getElementsByTagName('head')[0].appendChild(node);
    }
  }

并在构造函数中调用这个方法,

constructor() {
    this.loadScripts();
}

注意:如果需要动态加载更多脚本,请将它们添加到dynamicScripts数组中。

其他回答

@ rahull -kumar的解决方案对我来说很好,但我想在我的typescript中调用我的javascript函数

foo.myFunctions() // works in browser console, but foo can't be used in typescript file

我通过在我的typescript中声明它来修复它:

import { Component } from '@angular/core';
import { ScriptService } from './script.service';
declare var foo;

现在,我可以在typcript文件的任何地方调用foo

您可以使用谷歌标签管理器来管理外部脚本,而无需进入代码。对于非技术用户和技术用户来说,这是一个完美的解决方案。

我已经修改了@rahul kumars的答案,所以它使用可观察的代替:

import { Injectable } from "@angular/core";
import { Observable } from "rxjs/Observable";
import { Observer } from "rxjs/Observer";

@Injectable()
export class ScriptLoaderService {
    private scripts: ScriptModel[] = [];

    public load(script: ScriptModel): Observable<ScriptModel> {
        return new Observable<ScriptModel>((observer: Observer<ScriptModel>) => {
            var existingScript = this.scripts.find(s => s.name == script.name);

            // Complete if already loaded
            if (existingScript && existingScript.loaded) {
                observer.next(existingScript);
                observer.complete();
            }
            else {
                // Add the script
                this.scripts = [...this.scripts, script];

                // Load the script
                let scriptElement = document.createElement("script");
                scriptElement.type = "text/javascript";
                scriptElement.src = script.src;

                scriptElement.onload = () => {
                    script.loaded = true;
                    observer.next(script);
                    observer.complete();
                };

                scriptElement.onerror = (error: any) => {
                    observer.error("Couldn't load script " + script.src);
                };

                document.getElementsByTagName('body')[0].appendChild(scriptElement);
            }
        });
    }
}

export interface ScriptModel {
    name: string,
    src: string,
    loaded: boolean
}

对于下面的链接,我也有同样的问题。我用一种很简单的方法解决了它。

https://www.gstatic.com/charts/loader.js

我需要访问下面代码中的谷歌变量。但当我把它放到angular类中时,它就不起作用了。

google.charts.load("current", {packages:['corechart']});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
    var data = google.visualization.arrayToDataTable([
        ["Element", "Density", { role: "style" } ],
        ["Copper", 8.94, "dodgerblue"],
        ["Silver", 10.49, "dodgerblue"],
        ["Gold", 19.30, "dodgerblue"],
        ["Platinum", 21.45, "color: dodgerblue"]
    ]);
var view = new google.visualization.DataView(data);
view.setColumns([0, 1,
    { calc: "stringify",
        sourceColumn: 1,
        type: "string",
        role: "annotation" },
    2]);

var options = {
    title: "Density of Precious Metals, in g/cm^3",
    width: 600,
    height: 400,
    bar: {groupWidth: "50%"},
    legend: { position: "none" },
};
var chart = new google.visualization.ColumnChart(document.getElementById("columnchart_values"));
chart.draw(view, options);

}

我在ts类的顶部创建了一个具有相同名称的全局变量(谷歌),然后该变量自动引用所需的变量。(因为它是全局作用域)那么问题就解决了。

declare var google: any;

您可以像这样在组件中动态加载多个脚本。ts文件:

 loadScripts() {
    const dynamicScripts = [
     'https://platform.twitter.com/widgets.js',
     '../../../assets/js/dummyjs.min.js'
    ];
    for (let i = 0; i < dynamicScripts.length; i++) {
      const node = document.createElement('script');
      node.src = dynamicScripts[i];
      node.type = 'text/javascript';
      node.async = false;
      node.charset = 'utf-8';
      document.getElementsByTagName('head')[0].appendChild(node);
    }
  }

并在构造函数中调用这个方法,

constructor() {
    this.loadScripts();
}

注意:如果需要动态加载更多脚本,请将它们添加到dynamicScripts数组中。