Question

I know that I shouldn’t be building a new associated image for my gallery in the Gallery view partial. However, I can’t figure out to do this in ActiveAdmin’s generated controller, which can apparently be customized using the “Controller” method in the resource file. How can I do this using the Controller method instead of the view partial?

Here is my Gallery resource file:

ActiveAdmin.register Gallery do

  controller.authorize_resource

  scope_to :current_admin_user

  before_filter :block_access

  controller do
    def block_access
      if params && params['q'] && params['q']['admin_user_id_eq']
        params['q']['admin_user_id_eq'] = nil
      end
    end
  end

 form :partial => "form"

end

Here is my Gallery view partial:

  <% new_image = @gallery.images.build %>  
  <%= semantic_form_for [:admin, @gallery] do |g| %>
    <%= g.inputs "Details" do %>
      <%= g.input :title %>
      <%= g.input :images, :as => :check_boxes, :label_method => Proc.new { |image| image_tag(image.thumb_path, :alt => "") + content_tag("h3", image.title)  } %>
    <% end %>
    <%= g.inputs :for => [:images, new_image], :name => "New Image" do |image| %>
      <% if image.object.new_record? %>
        <%= image.input :title %>
        <%= image.input :asset, :as => :file %>
      <% end %>
    <% end %>
    <%= g.buttons %>
  <% end %>

UPDATE #1: Adding the following methods inside the “controller do” block (based on the suggestion of Thomas Watson) worked for creating/editing Galleries.

def new
  @gallery = Gallery.new
  @new_image = @gallery.images.build
  new!
end

def edit
  @gallery = Gallery.find(params[:id])
  @new_image = @gallery.images.build
  edit!
end

def update
  @gallery = Gallery.find(params[:id])
  @new_image = @gallery.images.build
  update!
end

Answer 1

Active Admin depends on Inherited Resources for its action magic. You can open up any controller action and add stuff to it. You can even create your own instance variable and Active Admin will automatically use that instead of creating its own.

In your case you would do something like this if you where to build it on the new action:

ActiveAdmin.register Gallery do
  controller do
    def new
      @gallery = Gallery.new
      @new_image = @gallery.images.build

      # call `new!` to ensure that the rest of the action continues as normal
      new!
    end
  end
end