Rails Admin: creating a custom action

Rails Admin is an excellent way of quickly creating a backend for your website. It’s simply perfect for that project that is focused on frontend but you still need a backend to do simple management tasks.

Although it’s very complete, sometimes you may want to customize a few things and for this you can create a custom action.

If you have, for example, a list of articles. It would be good if you could bulk publish them, instead of going and editing one by one. Fortunately this is possible and quite simple, although it’s not very clear in Rails Admin manual.

1. Create your custom action

Let’s create our custom action. Create file lib/rails_admin_publish.rb with the following content:

require 'rails_admin/config/actions'
require 'rails_admin/config/actions/base'

module RailsAdminPublish
end

module RailsAdmin
  module Config
    module Actions
      class Publish < RailsAdmin::Config::Actions::Base
        # There are several options that you can set here. 
        # Check https://github.com/sferik/rails_admin/blob/master/lib/rails_admin/config/actions/base.rb for more info.

        register_instance_option :bulkable? do
          true
        end

        register_instance_option :controller do
          Proc.new do
            # Get all selected rows
            @objects = list_entries(@model_config, :destroy)

            # Update field published to true
            @objects.each do |object|
              object.update_attribute(:published, true)
            end

            flash[:success] = "#{@model_config.label} successfully published."

            redirect_to back_or_index
          end
        end
      end
    end
  end
end

What exactly this does? Well, first it defines this action as bulkable. There are many other options that you can set here, check the comment next to that line for more information.

After that, we create a Proc with our action. In summary, it’s getting all entries and looping to update the attribute published. After that, it sets a flash message and redirect to index.

2. Let Rails Admin know that your custom action exists

Open config/initializers/rails_admin.rb and add the following code before RailsAdmin.config:

require Rails.root.join('lib', 'rails_admin_publish.rb')

Them add this inside RailsAdmin.config:

# Register the class in lib/rails_admin_publish.rb
module RailsAdmin
  module Config
    module Actions
      class Publish < RailsAdmin::Config::Actions::Base
        RailsAdmin::Config::Actions.register(self)
      end
    end
  end
end

c.actions do
  # root actions
  dashboard                     # mandatory
  # collection actions
  index                         # mandatory
  new
  export
  history_index
  bulk_delete
  # member actions
  show
  edit
  delete
  history_show
  show_in_app

  # Set the custom action here
  publish do
    # Make it visible only for article model. You can remove this if you don't need.
    visible do
      bindings[:abstract_model].model.to_s == "Article"
    end
  end
end

What it does is to first register the publish action and them tell Rails Admin where it should be visible. If you want to make it visible for all models, simply remove that visible part and it should work correctly.

That’s it, restart your server and test. The bulk action should be there.

In case you still have questions I’ve forked dummy_app, which is a sample app created to show Rails Admin, and used it to create a custom action. Check it out in Github https://github.com/fernandomm/dummy_app