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
我发现这个解决方案更干净，首先在你的模块中导入HttpClientJsonpModule，然后做这样的事情
this.apiLoaded = this.httpClient.jsonp(environment.AnyApiUrl, 'callback')
.pipe(
map(() => true),
catchError(() => of(false)),
);
在模板中:
<app-component *ngIf="apiLoaded | async"></app-component>
这个解决方案在Angular谷歌Maps的官方文档中。
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));
}
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();
}
});
}
}
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); }
我发现这个解决方案更干净，首先在你的模块中导入HttpClientJsonpModule，然后做这样的事情
this.apiLoaded = this.httpClient.jsonp(environment.AnyApiUrl, 'callback')
.pipe(
map(() => true),
catchError(() => of(false)),
);
在模板中:
<app-component *ngIf="apiLoaded | async"></app-component>
这个解决方案在Angular谷歌Maps的官方文档中。
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();
});
