def create
      @share_link = @file.share_links.build(permitted_params.share_link)
      @share_link.user = boxroom_current_user

      if @share_link.save
        UserMailer.share_link_email(@share_link).deliver_now
        redirect_to @folder, :notice => t(:shared_successfully)
      else
        render :action => 'new'
      end
    end
def create
      @share_link = @file.share_links.build(permitted_params.share_link)
      @share_link.user = boxroom_current_user

      if @share_link.save
        UserMailer.share_link_email(@share_link).deliver_now
        redirect_to @folder, :notice => t(:shared_successfully)
      else
        render :action => 'new'
      end
    end
Note: @file and @folder are set in require_existing_file