Question

I am having difficulty using carrierwave together mongoid. I am writing an application that requires images to be stored in a number of collections, so I have created the Image class as follows (please excuse the use of imageable):

class Image
  include Mongoid::Document

  embedded_in :imageable, polymorphic: true

  mount_uploader :file, ImageUploader
end

ImageUploader is as created by rails generate uploader Image.

Then I have a story model:

class Story
  include Mongoid::Document
  include Mongoid::Timestamps

  field :title, :type => String
  field :content, :type => String
  field :category, :type => String

  embeds_many :blog_images, as: :imageable
end

When I try to create a Story object, i get the error uninitialized constant BlogImage even if I do not supply and image through the form. I have also tried in the console to call story.blog_images << Image.new with the same error.

In my gem file I have:

gem 'carrierwave'
gem 'carrierwave-mongoid', :require => 'carrierwave/mongoid'

My versions are Mongoid – 2.4.7 and carrierwave – 0.6.2.

My main question is how to fix this error, but I am also not too sure about how to set up the form to receive these images. (Ideally I’d like to use javascript to add a new dialog, each time a file is selected.) Is there something wrong with the way I have set up my models or am using carrierwave?

Answer 1

You will need to specify the target class for blog_images because it cannot be derived from the name of the relation. Try:

embeds_many :blog_images, as: :imageable, :class_name => 'Image'