How to detect async change to ng-content

Adding an @Input() content; and using the component like

<markdown [content]="info"></markdown>

would make this easier.

Alternatively a MutationObserver should work well for this specific use case.

Even if the Günter's answer is great, I wasn't able to resist to create a little plunkr describing how to use Marked into a component: https://plnkr.co/edit/0oSeaIyMWoq5fAKKlJLA?p=preview.

Here are the details:

• Marked configuration the HTML file

  <script>
    System.config({
      transpiler: 'typescript', 
      typescriptOptions: { emitDecoratorMetadata: true }, 
      packages: {
        'src': {defaultExtension: 'ts'}
      },
      map: {
        marked: 'https://cdnjs.cloudflare.com/ajax/libs/marked/0.3.5/marked.js'
      }
    });
    System.import('src/boot')
      .then(null, console.error.bind(console));
  </script>
  

• The component that uses Marked

  import { Component, Input } from 'angular2/core';
  import marked from 'marked';
  
  @Component({
    selector: 'markdown', 
    template: `
      <div [innerHTML]="convertedData"></div>
    `
  })
  export class MarkdownComponent {
    @Input('data')
    data:string;
  
    ngOnChanges() { 
      this.convertedData = marked(this.data);
    }
  }
  

• The component that uses the previous Markdown component

  import { Component } from 'angular2/core';
  import { MarkdownComponent } from './markdown';
  
  @Component({
    selector: 'my-app', 
    template: `
      <div>
        <markdown [data]="markdown"></markdown>
      </div>
    `,
    directives: [ MarkdownComponent ]
  })
  export class AppComponent {
    constructor() {
      this.markdown = 'Hello';
  
      setTimeout(() => {
        this.markdown = `
  # Title
  
  Some __test__
  `;
      }, 1000);
    }
  }