Rails 3 - trying to create polymorphic has_one association in console

Question

Here's my code:

Models:

class Article < ActiveRecord::Base
  attr_accessible :title, :author, :content, :imageable_attributes

  has_one :image, as: :imageable, dependent: :destroy
  accepts_nested_attributes_for :image, allow_destroy: true

  validates_presence_of :title, :content, :author
end

class Image < ActiveRecord::Base
  mount_uploader :image, ImageUploader
  attr_accessible :image, :caption, :imageable_id, :imageable_type, :article_ref

  validates_presence_of :image
  belongs_to :imageable, :polymorphic => true
end

Here's what I've tried in console:

article = Article.create!(title: "test", content: "test", author: "test", image_attributes: {image: "test.jpg", caption: "test caption"})

This creates an Article without errors, but if I call:

article.image

I get:

=> nil

If I type in console:

article = Article.new(title: "test", content: "test", author: "test")
article.build_image(image: "test.jpg")

I get:

=> Validation failed: Image image can't be blank

Any help greatly appreciated, I'm very confused!

Answer 1

I believe it's necessary to supply the attachment itself, rather than just the path. As an example,

i = Image.new(
  :image => File.join(Rails.root, "test.jpg")
)
i.image

# => 

but

i = Image.new(
  :image => File.open(File.join(Rails.root, "test.jpg"))
)
i.image

# => /uploads/tmp/20120427-2155-1316-5181/test.jpg

It's not necessary to use File.open when saving using Multipart POST, though.