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);

    }

}