How to load external scripts dynamically in Angular

0 votes

I have this module which componentize the external library together with additional logic without adding the <script> tag directly into the index.html:

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 {...}

I notice the import by ES6 spec is static and resolved during TypeScript transpiling rather than at runtime.

To make it configurable so the file.js will be loading either from CDN or local folder? How to tell Angular 2 to load a script dynamically?

Sep 8, 2020 in Web Development by kartik
• 37,520 points
5,397 views

1 answer to this question.

0 votes

Hello @kartik,

You can use following technique to dynamically load JS scripts and libraries on demand in your Angular project.

script.store.ts will contain the path of the script either locally or on a remote server and a name that will be used to load the script dynamically

 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 is an injectable service that will handle the loading of script, copy script.service.ts as it is

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);
        }
    });
}

}

Inject this ScriptService wherever you need it and load js libs like this

this.script.load('filepicker', 'rangeSlider').then(data => {
    console.log('script loaded ', data);
}).catch(error => console.log(error));

Hope it helps!!

Want to know more about Angular? Get your Angular Certification Course today and become certified.
Thank you!!

answered Sep 8, 2020 by Niroj
• 82,840 points

Related Questions In Web Development

0 votes
1 answer
0 votes
1 answer

Why does the WebView html in my Mac app refuse to load JQuery or any external script?

I changed https://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js to http://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js and now it works. If anyone ...READ MORE

answered Aug 5, 2022 in Web Development by rajatha
• 7,680 points
858 views
0 votes
0 answers

How to implement a debounce time in keyup event in Angular 6

How to implement a debounce time in ...READ MORE

Oct 25 in Web Development by Nidhi
• 2,400 points
47 views
0 votes
0 answers

How to use ngIf in Angular?

How to use ngIf in Angular? I'm trying ...READ MORE

Oct 26 in Web Development by Nidhi
• 2,400 points
68 views
0 votes
1 answer

What are the vulnerability related to PHP Form?

Hii, The $_SERVER["PHP_SELF"] variable can be used by ...READ MORE

answered Feb 13, 2020 in PHP by Niroj
• 82,840 points
3,172 views
+1 vote
1 answer

How can we send message multiple time to a specific person or group in whatsapp using loop?

Hii @kartik,  This is simple task to send single ...READ MORE

answered Feb 28, 2020 in Java-Script by Niroj
• 82,840 points
18,580 views
0 votes
1 answer

What is meant by passing the variable by value and reference in PHP?

Hello, When the variable is passed as value ...READ MORE

answered Mar 27, 2020 in PHP by Niroj
• 82,840 points
3,254 views
0 votes
1 answer

Connection with MySQL server using PHP. How can we do that?

Hey @kartik, You have to provide MySQL hostname, ...READ MORE

answered Mar 27, 2020 in PHP by Niroj
• 82,840 points
1,288 views
+1 vote
1 answer

How to access the Angularjs scope of a particular html element from our console?

Hello, You should follow the below steps:-- 1.Compile and ...READ MORE

answered Jan 21, 2020 in Web Development by Niroj
• 82,840 points

edited Jan 21, 2020 by Niroj 2,937 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP