Javascript 如何在Angular中动态加载外部脚本?
我有一个模块,它将外部库与其他逻辑组合在一起,而无需将Javascript 如何在Angular中动态加载外部脚本?,javascript,angular,typescript,ecmascript-6,Javascript,Angular,Typescript,Ecmascript 6,我有一个模块,它将外部库与其他逻辑组合在一起,而无需将标记直接添加到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"><
标记直接添加到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 {...}
导入'http://external.com/path/file.js'
//导入“../js/file.js”
@组成部分({
选择器:“我的应用程序”,
模板:`
模板`
})
导出类MyAppComponent{…}
我注意到ES6规范的import
是静态的,在TypeScript传输期间解析,而不是在运行时解析
无论如何,要使其可配置,以便文件.js将从CDN或本地文件夹加载?
如何告诉Angular 2动态加载脚本?如果您使用的是system.js,则可以在运行时使用
system.import()
:
export class MyAppComponent {
constructor(){
System.import('path/to/your/module').then(refToLoadedModule => {
refToLoadedModule.someFunction();
}
);
}
如果您使用的是webpack,您可以充分利用其强大的代码拆分支持,包括:
这可能有用。此代码在单击按钮时动态地将
标记附加到html文件的头部
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);
}
}
consturl='1〕http://iknow.com/this/does/not/work/either/file.js';
导出类MyAppComponent{
loadAPI:承诺;
公共按钮点击(){
this.loadAPI=新承诺((解析)=>{
log('resolving promise…');
这个.loadScript();
});
}
公共加载脚本(){
console.log('准备加载…')
让节点=document.createElement('script');
node.src=url;
node.type='text/javascript';
node.async=true;
node.charset='utf-8';
document.getElementsByTagName('head')[0].appendChild(节点);
}
}
您可以使用以下技术
在Angular项目中按需动态加载JS脚本和库
script.store.ts将包含本地或远程服务器上脚本的路径和用于动态加载脚本的名称
interface Scripts {
name: string;
src: string;
}
export const ScriptStore: Scripts[] = [
{name: 'filepicker', src: 'https://api.filestackapi.com/filestack.js'},
{name: 'rangeSlider', src: '../../../assets/js/ion.rangeSlider.min.js'}
];
script.service.ts是一个可注入的服务,它将按原样处理脚本加载、复制script.service.ts
import {Injectable} from "@angular/core";
import {ScriptStore} from "./script.store";
declare var document: any;
@Injectable()
export class ScriptService {
private scripts: any = {};
constructor() {
ScriptStore.forEach((script: any) => {
this.scripts[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);
}
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');
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);
}
});
}
}
将这个ScriptService
注入到任何需要的地方,然后像这样加载js库
this.script.load('filepicker', 'rangeSlider').then(data => {
console.log('script loaded ', data);
}).catch(error => console.log(error));
我已经修改了@rahul kumars answer,因此它使用了可观测值:
从“@angular/core”导入{Injectable};
从“rxjs/Observable”导入{Observable};
从“rxjs/Observer”导入{Observer};
@可注射()
导出类ScriptLoaderService{
私有脚本:ScriptModel[]=[];
公共负载(脚本:ScriptModel):可观察{
返回新的可观察对象((观察者:观察者)=>{
var existingScript=this.scripts.find(s=>s.name==script.name);
//如果已加载,请完成
if(existingScript&&existingScript.loaded){
下一步(现有脚本);
observer.complete();
}
否则{
//添加脚本
this.scripts=[…this.scripts,script];
//加载脚本
让scriptElement=document.createElement(“脚本”);
scriptElement.type=“text/javascript”;
scriptElement.src=script.src;
scriptElement.onload=()=>{
script.loaded=true;
下一步(脚本);
observer.complete();
};
scriptElement.onerror=(错误:any)=>{
错误(“无法加载脚本”+script.src);
};
document.getElementsByTagName('body')[0].appendChild(scriptElement);
}
});
}
}
导出接口脚本模型{
名称:string,
src:string,
已加载:布尔值
}
@d123546
我也遇到了同样的问题,现在在组件中使用ngAfterContentInit(生命周期挂钩)使其正常工作,如下所示:
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));
}
@rahul 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,我可以在我的TypeScript文件中的任何地方调用foo在我的例子中,我使用上述技术加载了js
和css
visjs
文件,效果非常好。我从ngOnInit()
注意:我可以通过简单地向html模板文件添加
和
标记来加载它
loadVisJsScript(){
log('loadingvisjs/css文件…');
让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(脚本);
让link=document.createElement(“link”);
link.type=“样式表”;
link.href=“../../assets/vis/vis.min.css”;
document.getElementsByTagName('head')[0].appendChild(链接);
}
您可以在组件.ts
文件中动态加载多个脚本:
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);
}
}
注意:要动态加载更多脚本,请将它们添加到dynamicScripts
数组。我已经使用新的渲染器api完成了此代码片段
constructor(private renderer: Renderer2){}
addJsToElement(src: string): HTMLScriptElement {
const script = document.createElement('script');
script.type = 'text/javascript';
script.src = src;
this.renderer.appendChild(document.body, script);
return script;
}
然后像这样称呼它
this.addJsToElement('https://widgets.skyscanner.net/widget-server/js/loader.js').onload = () => {
console.log('SkyScanner Tag loaded');
}
样品可以
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});
}
});
}
}
然后
或
我有一个动态加载脚本的好方法!
现在我在我的项目中使用ng6、echarts4(>700Kb)、ngx-echarts3。当我通过ngx echarts的文档使用它们时,我需要在angular.json中导入echarts:
“脚本”:[“/node_modules/echarts/dist/echarts.min.js”]
因此,在登录模块的页面中,加载scripts.js时,这是一个大文件!我不想要它
所以,我认为angular将每个模块作为一个文件加载,我可以插入一个路由器解析器来预加载js,然后开始模块加载
//预加载脚本解析器.s
this.addJsToElement('https://widgets.skyscanner.net/widget-server/js/loader.js').onload = () => {
console.log('SkyScanner Tag loaded');
}
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});
}
});
}
}
constructor(
private _script: ScriptLoaderService) {
}
ngAfterViewInit() {
this._script.loadScripts('app-wizard-wizard-3',
['assets/demo/default/custom/crud/wizard/wizard.js']);
}
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();
});
/**动态加载js的服务 */
@Injectable({
providedIn: 'root'
})
export class PreloadScriptResolver implements Resolve<IPreloadScriptResult[]> {
// Here import all dynamically js file
private scripts: any = {
echarts: { loaded: false, src: "assets/lib/echarts.min.js" }
};
constructor() { }
load(...scripts: string[]) {
const promises = scripts.map(script => this.loadScript(script));
return Promise.all(promises);
}
loadScript(name: string): Promise<IPreloadScriptResult> {
return new Promise((resolve, reject) => {
if (this.scripts[name].loaded) {
resolve({ script: name, loaded: true, status: 'Already Loaded' });
} else {
const script = document.createElement('script');
script.type = 'text/javascript';
script.src = this.scripts[name].src;
script.onload = () => {
this.scripts[name].loaded = true;
resolve({ script: name, loaded: true, status: 'Loaded' });
};
script.onerror = (error: any) => reject({ script: name, loaded: false, status: 'Loaded Error:' + error.toString() });
document.head.appendChild(script);
}
});
}
resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Promise<IPreloadScriptResult[]> {
return this.load(...route.routeConfig.data.preloadScripts);
}
}
const routes: Routes = [
{
path: "",
component: DashboardComponent,
canActivate: [AuthGuardService],
canActivateChild: [AuthGuardService],
resolve: {
preloadScripts: PreloadScriptResolver
},
data: {
preloadScripts: ["echarts"] // important!
},
children: [.....]
}
npm i scriptjs
npm install --save @types/scriptjs
import { get } from 'scriptjs';
export class AppComponent implements OnInit {
ngOnInit() {
get("https://maps.googleapis.com/maps/api/js?key=", () => {
//Google Maps library has been loaded...
});
}
}
import { Injectable } from '@angular/core';
import * as $ from 'jquery';
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 };
}
});
const 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) {
debugger;
loadOnce = loadOnce || false;
scripts.forEach((script: string) => {
if (!this._scripts[script]) {
this._scripts[script] = { src: script, loaded: false };
}
});
const 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) {
debugger;
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
const 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 });
}
});
}
reloadOnSessionChange() {
window.addEventListener('storage', function(data) {
if (data['key'] === 'token' && data['oldValue'] == null && data['newValue']) {
document.location.reload();
}
});
}
}
import {Inject, Injectable, PLATFORM_ID} from '@angular/core';
import {isPlatformBrowser} from "@angular/common";
@Injectable({
providedIn: 'root'
})
export class ScriptLoaderService {
constructor(
@Inject(PLATFORM_ID) private platformId: Object,
) {
}
load(scriptUrl: string) {
if (isPlatformBrowser(this.platformId)) {
let node: any = document.createElement('script');
node.src = scriptUrl;
node.type = 'text/javascript';
node.async = true;
node.charset = 'utf-8';
document.getElementsByTagName('head')[0].appendChild(node);
}
}
}
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);
}
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]'}
];
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);
}
});
}
}
constructor(private scriptLoaderService: ScriptLoaderService) {
this.scriptLoaderService.loadStyles('fancybox-css').then(x => {
this.scriptLoaderService.load('jquery', 'fancybox').then(data => {
}).catch(error => console.log(error));
});
}
https://www.gstatic.com/charts/loader.js
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);
declare var google: any;