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
示例可以是
script-loader.service。ts文件
import {Injectable} from '@angular/core';
import * as $ from 'jquery';
declare let document: any;
interface Script {
src: string;
loaded: boolean;
}
@Injectable()
export class ScriptLoaderService {
public _scripts: Script[] = [];
/**
* @deprecated
* @param tag
* @param {string} scripts
* @returns {Promise<any[]>}
*/
load(tag, ...scripts: string[]) {
scripts.forEach((src: string) => {
if (!this._scripts[src]) {
this._scripts[src] = {src: src, loaded: false};
}
});
let promises: any[] = [];
scripts.forEach((src) => promises.push(this.loadScript(tag, src)));
return Promise.all(promises);
}
/**
* Lazy load list of scripts
* @param tag
* @param scripts
* @param loadOnce
* @returns {Promise<any[]>}
*/
loadScripts(tag, scripts, loadOnce?: boolean) {
loadOnce = loadOnce || false;
scripts.forEach((script: string) => {
if (!this._scripts[script]) {
this._scripts[script] = {src: script, loaded: false};
}
});
let promises: any[] = [];
scripts.forEach(
(script) => promises.push(this.loadScript(tag, script, loadOnce)));
return Promise.all(promises);
}
/**
* Lazy load a single script
* @param tag
* @param {string} src
* @param loadOnce
* @returns {Promise<any>}
*/
loadScript(tag, src: string, loadOnce?: boolean) {
loadOnce = loadOnce || false;
if (!this._scripts[src]) {
this._scripts[src] = {src: src, loaded: false};
}
return new Promise((resolve, reject) => {
// resolve if already loaded
if (this._scripts[src].loaded && loadOnce) {
resolve({src: src, loaded: true});
}
else {
// load script tag
let scriptTag = $('<script/>').
attr('type', 'text/javascript').
attr('src', this._scripts[src].src);
$(tag).append(scriptTag);
this._scripts[src] = {src: src, loaded: true};
resolve({src: src, loaded: true});
}
});
}
}
和使用
第一次注射
constructor(
private _script: ScriptLoaderService) {
}
然后
ngAfterViewInit() {
this._script.loadScripts('app-wizard-wizard-3',
['assets/demo/default/custom/crud/wizard/wizard.js']);
}
or
this._script.loadScripts('body', [
'assets/vendors/base/vendors.bundle.js',
'assets/demo/default/base/scripts.bundle.js'], true).then(() => {
Helpers.setLoading(false);
this.handleFormSwitch();
this.handleSignInFormSubmit();
this.handleSignUpFormSubmit();
this.handleForgetPasswordFormSubmit();
});
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。
@ 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
示例可以是
script-loader.service。ts文件
import {Injectable} from '@angular/core';
import * as $ from 'jquery';
declare let document: any;
interface Script {
src: string;
loaded: boolean;
}
@Injectable()
export class ScriptLoaderService {
public _scripts: Script[] = [];
/**
* @deprecated
* @param tag
* @param {string} scripts
* @returns {Promise<any[]>}
*/
load(tag, ...scripts: string[]) {
scripts.forEach((src: string) => {
if (!this._scripts[src]) {
this._scripts[src] = {src: src, loaded: false};
}
});
let promises: any[] = [];
scripts.forEach((src) => promises.push(this.loadScript(tag, src)));
return Promise.all(promises);
}
/**
* Lazy load list of scripts
* @param tag
* @param scripts
* @param loadOnce
* @returns {Promise<any[]>}
*/
loadScripts(tag, scripts, loadOnce?: boolean) {
loadOnce = loadOnce || false;
scripts.forEach((script: string) => {
if (!this._scripts[script]) {
this._scripts[script] = {src: script, loaded: false};
}
});
let promises: any[] = [];
scripts.forEach(
(script) => promises.push(this.loadScript(tag, script, loadOnce)));
return Promise.all(promises);
}
/**
* Lazy load a single script
* @param tag
* @param {string} src
* @param loadOnce
* @returns {Promise<any>}
*/
loadScript(tag, src: string, loadOnce?: boolean) {
loadOnce = loadOnce || false;
if (!this._scripts[src]) {
this._scripts[src] = {src: src, loaded: false};
}
return new Promise((resolve, reject) => {
// resolve if already loaded
if (this._scripts[src].loaded && loadOnce) {
resolve({src: src, loaded: true});
}
else {
// load script tag
let scriptTag = $('<script/>').
attr('type', 'text/javascript').
attr('src', this._scripts[src].src);
$(tag).append(scriptTag);
this._scripts[src] = {src: src, loaded: true};
resolve({src: src, loaded: true});
}
});
}
}
和使用
第一次注射
constructor(
private _script: ScriptLoaderService) {
}
然后
ngAfterViewInit() {
this._script.loadScripts('app-wizard-wizard-3',
['assets/demo/default/custom/crud/wizard/wizard.js']);
}
or
this._script.loadScripts('body', [
'assets/vendors/base/vendors.bundle.js',
'assets/demo/default/base/scripts.bundle.js'], true).then(() => {
Helpers.setLoading(false);
this.handleFormSwitch();
this.handleSignInFormSubmit();
this.handleSignUpFormSubmit();
this.handleForgetPasswordFormSubmit();
});
嗨，你可以使用Renderer2和elementRef只需几行代码:
constructor(private readonly elementRef: ElementRef,
private renderer: Renderer2) {
}
ngOnInit() {
const script = this.renderer.createElement('script');
script.src = 'http://iknow.com/this/does/not/work/either/file.js';
script.onload = () => {
console.log('script loaded');
initFile();
};
this.renderer.appendChild(this.elementRef.nativeElement, script);
}
onload函数可以用来在脚本加载后调用脚本函数，如果你必须在ngOnInit()中进行调用，这是非常有用的。
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。
