Not a symbol.

[CraneWing]

I am using CPK so that I can edit a join table in Active Admin. I have a table category_recipes, with two columns, recipe_id and category_id. This is the model I am using for the table's index page in Active Admin.

require 'composite_primary_keys'

ActiveAdmin.register CategoryRecipe do

   form do |f|
      f.semantic_errors
      inputs 'Catgory Recipes' do
         input :category_id
         input :recipe_id
      end
      f.submit
   end

   remove_filter :category
   remove_filter :recipe

   permit_params :category_id, :recipe_id
end

My exact error is ["category_id", "recipe_id"] is not a symbol.

The error is being thrown in Active Admin's display_helper, in this block:

    module DisplayHelper

      DISPLAY_NAME_FALLBACK = ->{

        name, klass = "", self.class
        name << klass.model_name.human         if klass.respond_to? :model_name
        name << " ##{send(klass.primary_key)}" if klass.respond_to? :primary_key
        name.present? ? name : to_s

      }

Using Rails 4.2, ActiveRecord 4.2, composite_primary_keys 8.1.0.

[cfis]

You have to setup the model to have a composite key. That is generally done like this:

class MyClass
self.primary_keys = [:id1, :id2]
end

[CraneWing]

I have that exactly in my code, as the documentation says, but I still get the error.

[IMhide]

I had the exact same error.

When you look at the stack can see that it comes from the generated title

["user_id", "project_id"] is not a symbol


activeadmin (1.0.0.pre2) lib/active_admin/view_helpers/display_helper.rb:8:in `block in <module:DisplayHelper>'
activeadmin (1.0.0.pre2) lib/active_admin/view_helpers/method_or_proc_helper.rb:86:in `instance_exec'
activeadmin (1.0.0.pre2) lib/active_admin/view_helpers/method_or_proc_helper.rb:86:in `render_in_context'
activeadmin (1.0.0.pre2) lib/active_admin/view_helpers/display_helper.rb:18:in `display_name'
arbre (1.0.3) lib/arbre/element.rb:180:in `method_missing'
activeadmin (1.0.0.pre2) lib/active_admin/views/pages/show.rb:36:in `default_title'
--> activeadmin (1.0.0.pre2) lib/active_admin/views/pages/show.rb:14:in `title' <--
[...]

You can simply fix it by overriding the page title of the ActiveAdmin Ressource view this way :

controller do
  def show
    @page_title = "Awesome Title"
  end
end

Now ActiveAdmin works well with composite-primary-key