活动管理字段上的布尔值返回空而不是true或false（Rails 3.2 / Active Admin）

Question

I am building a daily deal app to train learning RoR.

On my Deal form, I have a boolean field called "featured". If I check the checkbox, the deal is featured (as opposed to a draft).

But when I create on active admin my Deal, if I check the checkbox, I do get 'true' (that part is ok), but if I don't check it, I am getting 'empty' instead of 'false' .

Shouldn't I get false?

Here are my files:

schema migration:

create_table "deals", :force => true do |t|
  t.string   "title"
  t.string   "description"
  t.boolean  "featured"
  t.integer  "admin_user_id"
  t.datetime "created_at",       :null => false
  t.datetime "updated_at",       :null => false
end

And the form on Active Admin (it uses formtastic for forms by default I think)

ActiveAdmin.register Deal do

  controller do 
    with_role :admin_user
  end

    form do |f|            

    f.inputs "Content" do
      f.input :description,       :label => "Deal description"
      f.input :title,             :label => "Deal title"

    end

    f.inputs "Status" do
     f.input :featured,          :label => "Status of publication (draft or featured)"
    end

    f.inputs "Publisher" do
      f.input :admin_user_id, :as => :select, :collection => AdminUser.all, :label => "Campaign Account Manager"
    end

    f.actions
  end

end

Anybody has an idea why in the column "featured" I can read "empty" instead of "false" when I don't check the checkbox of the "featured" field when creating Deals?

Answer 1

I am assuming that by 'empty', you don't mean the literal but you mean the field has no value or is empty. You haven't set a default for the field or entered any data into it, so it is empty or, in the Ruby vernacular, nil. To set a default, you can do something like this:

create_table "deals", :force => true do |t|
  t.string   "title"
  t.string   "description"
  t.boolean  "featured"          :default => false
  t.integer  "admin_user_id"
  t.datetime "created_at",       :null => false
  t.datetime "updated_at",       :null => false 

There are other methods for setting defaults as well, for more complex values. For example, if you wanted to set the default for a datetime field to the current time, you would use a before_create exit:

  before_create :set_foo_to_now
  def set_foo_to_now
    self.foo = Time.now
  end

Or, you can simply make sure you enter a value when you create the new record yourself.

As a reference, see this text on ActiveRecord migrations .