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

@d123546 我遇到了同样的问题,现在使用ngAfterContentInit(生命周期钩子)在组件中工作,就像这样:

import { Component, OnInit, AfterContentInit } from '@angular/core';
import { Router } from '@angular/router';
import { ScriptService } from '../../script.service';

@Component({
    selector: 'app-players-list',
    templateUrl: './players-list.component.html',
    styleUrls: ['./players-list.component.css'],
    providers: [ ScriptService ]
})
export class PlayersListComponent implements OnInit, AfterContentInit {

constructor(private router: Router, private script: ScriptService) {
}

ngOnInit() {
}

ngAfterContentInit() {
    this.script.load('filepicker', 'rangeSlider').then(data => {
    console.log('script loaded ', data);
    }).catch(error => console.log(error));
}

其他回答

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。

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
}

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。

我希望能够:

Add a script when the app is being bootstrapped Not do it from a component, because it doesn't feel like it's any component's responsibility Not do it from a directive, because of the same reason as the component Not do it from a service, because unless there's some kind of heavy logic related to an existing service, this doesn't belong IMO to a service Avoid doing it in a module. A module could be fine but it's not as flexible as just using DI and since Angular 15 standalone components are stable so why bother with a module

也就是说,为了在应用程序引导之前做到这一点,这有点棘手。因为我们在那个阶段没有可用的渲染器,并且我们不能访问包含nativeElement的elementRef。

下面是我的看法:

export const YOUR_EXT_LIB_URL_TOKEN = new InjectionToken<string>('YOUR_EXT_LIB_URL_TOKEN');

export const YOUR_SETUP: Provider = {
  provide: APP_INITIALIZER,
  multi: true,
  useFactory: (
    doc: InjectionTokenType<typeof DOCUMENT>,
    rendererFactory: RendererFactory2,
    yourExternalLibToken: string,
  ) => {
    const renderer = rendererFactory.createRenderer(null, null);

    const script = renderer.createElement('script');
    script.type = 'text/javascript';
    script.src = yourExternalLibToken;
    renderer.appendChild(doc.body, script);

    return () => true;
  },
  deps: [DOCUMENT, RendererFactory2, YOUR_EXT_LIB_URL_TOKEN],
};

然后,您所要做的就是提供YOUR_EXT_LIB_URL_TOKEN并传递YOUR_SETUP提供程序。

这样,所有东西都是通过DI注入的,非常灵活。例如,您可以在共享库中提供YOUR_SETUP令牌,并在使用共享库的不同应用程序中提供YOUR_EXT_LIB_URL_TOKEN。

这可能有用。这段代码动态地将<script>标记附加到单击按钮时的html文件头部。

const url = 'http://iknow.com/this/does/not/work/either/file.js';

export class MyAppComponent {
    loadAPI: Promise<any>;

    public buttonClicked() {
        this.loadAPI = new Promise((resolve) => {
            console.log('resolving promise...');
            this.loadScript();
        });
    }

    public loadScript() {
        console.log('preparing to load...')
        let node = document.createElement('script');
        node.src = url;
        node.type = 'text/javascript';
        node.async = true;
        node.charset = 'utf-8';
        document.getElementsByTagName('head')[0].appendChild(node);
    }
}