How do I toggle bootstrap 4 modal using Angular2 Component/ Typescript

Question

I am not able to toggle a bootstrap modal using Typescript. I am using the default bootstrap 4 Modal. Here is the code.

<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>

And Here is a button that Bootstrap 4 provides to toggle the Modal

<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal">
  Launch demo modal
</button>

I am not using this button in my application. I want to show Modal through a function in one of my Angular 2 component. I have accessed the html element with the following code.

  ngOnInit() {
    this.modalElement = document.getElementById('myModal');
  }

Now I need to activate the modal to show it using a method call. I was not about to find a solution to do that. I tried methods like .show() and other solutions but none worked.