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
在我的例子中，我使用上述技术加载了js和css visjs文件-这非常有效。我从ngOnInit()中调用新函数
注意:我不能通过简单地添加一个<script>和<link>标签到html模板文件来加载它。
loadVisJsScript() { console.log('Loading visjs js/css files...'); let script = document.createElement('script'); script.src = "../../assets/vis/vis.min.js"; script.type = 'text/javascript'; script.async = true; script.charset = 'utf-8'; document.getElementsByTagName('head')[0].appendChild(script); let link = document.createElement("link"); link.type = "stylesheet"; link.href = "../../assets/vis/vis.min.css"; document.getElementsByTagName('head')[0].appendChild(link); }
其他回答
@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));
}
Angular有防止用户直接干扰html输出的逻辑。所以你必须让Angular通过在Angular中给出那个方向来注入标签。json文件。
首先，您必须获取脚本文件。有两种方法:
下载脚本文件(例如。somelibrary.js)
把它放在资产文件夹中 把脚本的相对路径，放到angular的“scripts”部分。json文件:
"scripts": [
"src/assets/somelibrary.js"
]
使用npm/yarn安装脚本:
把脚本的相对路径，放到angular的“scripts”部分。json文件:
"scripts": [
"./node_modules/somelibrary/dist/somelibrary.min.js"
]
对于那些也想动态加载样式的人。 (基于@Rahul Kumar的精彩回答)
script.store.ts
interface Scripts {
name: string;
src: string;
}
export const StyleStore: Scripts[] = [
{ name: 'fancybox-css', src: 'https://cdn.jsdelivr.net/gh/fancyapps/fancybox@3.5.7/dist/jquery.fancybox.min.css' }
];
export const ScriptStore: Scripts[] = [
{ name: 'jquery', src: 'https://cdn.jsdelivr.net/npm/jquery@3.5.1/dist/jquery.min.js' },
{ name: 'other', src: '[other script source]'}
];
script-loader.service.ts
import { Injectable } from '@angular/core';
import { ScriptStore, StyleStore } from '../../stores/script.store';
@Injectable({
providedIn: 'root'
})
export class ScriptLoaderService {
private scripts: any = {};
private styles: any = {};
constructor() {
ScriptStore.forEach((script: any) => {
this.scripts[script.name] = {
loaded: false,
src: script.src
};
});
StyleStore.forEach((script: any) => {
this.styles[script.name] = {
loaded: false,
src: script.src
};
});
}
load(...scripts: string[]) {
var promises: any[] = [];
scripts.forEach((script) => promises.push(this.loadScript(script)));
return Promise.all(promises);
}
loadStyles(...scripts: string[]) {
var promises: any[] = [];
scripts.forEach((script) => promises.push(this.loadStyle(script)));
return Promise.all(promises);
}
loadScript(name: string) {
return new Promise((resolve, reject) => {
//resolve if already loaded
if (this.scripts[name].loaded) {
resolve({ script: name, loaded: true, status: 'Already Loaded' });
}
else {
//load script
let script = document.createElement('script') as any;
script.type = 'text/javascript';
script.src = this.scripts[name].src;
if (script.readyState) { //IE
script.onreadystatechange = () => {
if (script.readyState === "loaded" || script.readyState === "complete") {
script.onreadystatechange = null;
this.scripts[name].loaded = true;
resolve({ script: name, loaded: true, status: 'Loaded' });
}
};
} else { //Others
script.onload = () => {
this.scripts[name].loaded = true;
resolve({ script: name, loaded: true, status: 'Loaded' });
};
}
script.onerror = (error: any) => resolve({ script: name, loaded: false, status: 'Loaded' });
document.getElementsByTagName('head')[0].appendChild(script);
}
});
}
loadStyle(name: string) {
return new Promise((resolve, reject) => {
//resolve if already loaded
if (this.styles[name].loaded) {
resolve({ script: name, loaded: true, status: 'Already Loaded' });
}
else {
//load style
let style = document.createElement('link') as any;
style.type = "text/css";
style.rel = "stylesheet";
style.href = this.styles[name].src;
if (style.readyState) { //IE
style.onreadystatechange = () => {
if (style.readyState === "loaded" || style.readyState === "complete") {
style.onreadystatechange = null;
this.styles[name].loaded = true;
resolve({ style: name, loaded: true, status: 'Loaded' });
}
};
} else { //Others
style.onload = () => {
this.styles[name].loaded = true;
resolve({ style: name, loaded: true, status: 'Loaded' });
};
}
style.onerror = (error: any) => resolve({ style: name, loaded: false, status: 'Loaded' });
document.getElementsByTagName('head')[0].appendChild(style);
}
});
}
}
app.component.ts
constructor(private scriptLoaderService: ScriptLoaderService) {
this.scriptLoaderService.loadStyles('fancybox-css').then(x => {
this.scriptLoaderService.load('jquery', 'fancybox').then(data => {
}).catch(error => console.log(error));
});
}
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。
