Adding script tags in Angular component template

Question

Angular2 removes <script> tags automatically from templates to stop people using this functionality as a "poor's man" loader.

The issue here is that script tags currently have more uses than just loading code or other script files. There is the possibility that further functionality around <script> tags will be introduced in future as well.

One current use is JSON-LD which takes the format

<script type="application/ld+json">
{
    "@context":"http://schema.org",
    "@type":"HealthClub",
    ...
}
</script>

A commonly suggested work around is to dynamically add script tags to the document via the ngAfterViewInit hook, but this is obviously not proper ng2 practice and will not work server side, which JSON-LD obviously needs to be able to do.

Are there any other workarounds that we can use to include <script> tags in angular2 templates (even if the tag is inert within the browser) or is this a case of the framework being too opinionated? What other solutions might exist if this situation can't be solved in angular2?

Answer 1

Maybe a little late to the party here, but since the above answers do not work well with Angular SSR (e.g. document is not defined server-side or document.createElement is not a function), I decided to write a version that works for Angular 4+, in both server and browser context:

Component Implementation

import { Renderer2, OnInit, Inject } from '@angular/core';
import { DOCUMENT } from '@angular/common';

class MyComponent implements OnInit {

    constructor(
        private _renderer2: Renderer2, 
        @Inject(DOCUMENT) private _document: Document
    ) { }

    public ngOnInit() {

        let script = this._renderer2.createElement('script');
        script.type = `application/ld+json`;
        script.text = `
            {
                "@context": "https://schema.org"
                /* your schema.org microdata goes here */
            }
        `;

        this._renderer2.appendChild(this._document.body, script);
    }
}

Service Implementation

NOTE: Services cannot use Renderer2 directly. In fact, rendering an element is supposed to be done by a Component. However, you might find yourself in situation where you want to automate the creation of JSON-LD script tags on a page. As an example, a situation could be to invoke such function on route navigation change events. Hence I decided to add a version that works in a Service context.

import { Renderer2, Inject } from '@angular/core';
import { DOCUMENT } from '@angular/common';

/**
 * Use a Service to automate creation of JSON-LD Microdata.
 */
class MyService {

    constructor(
        @Inject(DOCUMENT) private _document: Document
    ) { }

    /**
     * Set JSON-LD Microdata on the Document Body.
     *
     * @param renderer2             The Angular Renderer
     * @param data                  The data for the JSON-LD script
     * @returns                     Void
     */
    public setJsonLd(renderer2: Renderer2, data: any): void {

        let script = renderer2.createElement('script');
        script.type = 'application/ld+json';
        script.text = `${JSON.stringify(data)}`;

        renderer2.appendChild(this._document.body, script);
    }
}