Whenever the delivered preview providers don't meet the requirements for a special preview, it is possible to implement your own preview provider. Implementations may use the base implementation AbstractContentPreviewProvider, which already implements some more common aspects, like checking the preview settings for restrictions to a site or certain content types. (see the Javadocs for details).

  public class CustomPreviewProvider extends AbstractContentPreviewProvider
  {
    public CustomPreviewProvider(SitesService sitesService) {
      super(sitesService);
    }
    ...
  }

A very basic example of an implementation has to implement these additional methods: