Pattern Factory return [object Object] in my HTML

When I use my pattern factory for my slider, it returns me "[object Object]" instead of having HTML.
Class code

HTML develop tools

Do you have any idea what could happen?

Thank you so much 🙂

>Solution :

Contructor cann’t return anything, but the object he creates and returns internally. To avoid this behavior use something like.

   class MediaFactory {
      getContent(data, layout) {
         // your code goes here
      }

   }

and usage will be

....innerHtml = new MediaFactory().getContent(article, 'slider')