If you have data you want on a standalone page that isn't tied to a resource, custom pages provide you with a familiar syntax and feature set:

• a menu item
• sidebars
• action items
• page actions

Creating a page is as simple as calling register_page:

# app/admin/calendar.rb
ActiveAdmin.register_page "Calendar" do
  content do
    para "Hello World"
  end
end

Anything rendered within content will be the main content on the page. Partials behave exactly the same way as they do for resources:

# app/admin/calendar.rb
ActiveAdmin.register_page "Calendar" do
  content do
    render partial: 'calendar'
  end
end

# app/views/admin/calendar/_calendar.html.arb
table do
  thead do
    tr do
      %w[Sunday Monday Tuesday Wednesday Thursday Friday Saturday].each &method(:th)
    end
  end
  tbody do
    # ...
  end
end

See the Menu documentation.

ActiveAdmin.register_page "Calendar" do
  breadcrumb do
    ['admin', 'calendar']
  end
end

We use the admin namespace by default, but you can use anything:

# Available at /today/calendar
ActiveAdmin.register_page "Calendar", namespace: :today

# Available at /calendar
ActiveAdmin.register_page "Calendar", namespace: false

To nest the page within another resource, you can use the belongs_to method:

ActiveAdmin.register Project
ActiveAdmin.register_page "Status" do
  belongs_to :project
end

See also the Belongs To documentation and examples.

See the Sidebars documentation.

Just like other resources, you can add action items. The difference here being that :only and :except don't apply because there's only one page it could apply to.

action_item :view_site do
  link_to "View Site", "/"
end

Page actions are custom controller actions (which mirror the resource DSL for the same feature).

page_action :add_event, method: :post do
  # ...
  redirect_to admin_calendar_path, notice: "Your event was added"
end

action_item :add do
  link_to "Add Event", admin_calendar_add_event_path, method: :post
end

This defines the route /admin/calendar/add_event which can handle HTTP POST requests.

Clicking on the action item will reload page and display the message "Your event was added"

Page actions can handle multiple HTTP verbs.

page_action :add_event, method: [:get, :post] do
  # ...
end

See also the Custom Actions example.

You can use custom parameter instead of id

ActiveAdmin.register User do
  controller do
    defaults :finder => :find_by_name
  end
end

This defines the resource route as /admin/users/john if user name is john