```ruby
module RailsAdmin
  module Config
    module Actions
      class CustomShowInApp < RailsAdmin::Config::Actions::Base
        RailsAdmin::Config::Actions.register(self)

        register_instance_option :member do
          true
        end

        register_instance_option :visible? do
          authorized? && (bindings[:controller].main_app.url_for(bindings[:object]) rescue false)
        end

        register_instance_option :controller do
          Proc.new do
            if @object.class.name == 'Page'
              redirect_to main_app.page_url(@object)
            elsif @object.class.name == 'News'
              redirect_to main_app.news_url(@object)
            elsif @object.class.name == 'Obj'
              redirect_to main_app.object_url(@object.category, @object)
            else
              redirect_to main_app.url_for(@object)
            end
          end
        end

        register_instance_option :link_icon do
          'icon-eye-open'
        end

        register_instance_option :pjax? do
          false
        end
      end
    end
  end
end
```

Fix show in app for pages
user
```ruby
module RailsAdmin
  module Config
    module Actions
      class CustomShowInApp < RailsAdmin::Config::Actions::Base
        RailsAdmin::Config::Actions.register(self)

        register_instance_option :member do
          true
        end

        register_instance_option :visible? do
          authorized? && (bindings[:controller].main_app.url_for(bindings[:object]) rescue false)
        end

        register_instance_option :controller do
          Proc.new do
            if @object.class.name == 'Page'
              if @object.fullpath.blank?
                redirect_to main_app.page_url(@object)
              else
                redirect_to @object.fullpath
              end
            elsif @object.class.name == 'News'
              redirect_to main_app.news_url(@object)
            elsif @object.class.name == 'Obj'
              redirect_to main_app.object_url(@object.category, @object)
            else
              redirect_to main_app.url_for(@object)
            end
          end
        end

        register_instance_option :link_icon do
          'icon-eye-open'
        end

        register_instance_option :pjax? do
          false
        end
      end
    end
  end
end
```
assistant