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
对于下面的链接，我也有同样的问题。我用一种很简单的方法解决了它。
https://www.gstatic.com/charts/loader.js
我需要访问下面代码中的谷歌变量。但当我把它放到angular类中时，它就不起作用了。
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);
}
我在ts类的顶部创建了一个具有相同名称的全局变量(谷歌)，然后该变量自动引用所需的变量。(因为它是全局作用域)那么问题就解决了。
declare var google: any;
其他回答
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); }
@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));
}
对于下面的链接，我也有同样的问题。我用一种很简单的方法解决了它。
https://www.gstatic.com/charts/loader.js
我需要访问下面代码中的谷歌变量。但当我把它放到angular类中时，它就不起作用了。
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);
}
我在ts类的顶部创建了一个具有相同名称的全局变量(谷歌)，然后该变量自动引用所需的变量。(因为它是全局作用域)那么问题就解决了。
declare var google: any;
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。
