jystewart / image-associations

ActiveRecord extensions to make it easier to manage attachments

ImageAssociations
=================

One thing I frequently find myself doing is associating multiple images with a given model. My news story might have a banner image, and a series of other attachments, which I could specify with:

class Story < ActiveRecord::Base
  belongs_to :banner_image
  has_many :story_attachments
end

class BannerImage < ActiveRecord::Base
  has_attachment # I'm using attachment_fu
end

class StoryAttachment < ActiveRecord::Base
  has_attachment # I'm using attachment_fu
end

(or I could use has_one in place of belongs_to there, your tastes/requirements may vary)

What quickly becomes a pain is assigning the images to the models, and having rejected fat controllers I often end up writing accessors on my models to manage that for me:

class Story < ActiveRecord::Base
  belongs_to :banner_image
  has_many :story_attachments
  
  def banner_image(data)
    if valid_file?(data)
      self.banner_image = BannerImage.create(:uploaded_data => data)
    end
  end
  
  def valid_file?
    # etc.
  end
end

That quickly gets dull, so I've wrapped it up in a plugin I'm calling image_associations. With that I can write:

class Story < ActiveRecord::Base
  belongs_to_image :banner_image
  has_many_images :story_attachments
end

and get the accessors for free.


Example
=======

class Story < ActiveRecord::Base
  belongs_to_image :banner_image
  has_many_images :story_attachments
end

s = Story.new
s.story_attachments = [file_one, file_two]
s.banner_image = file_tree
s.save

Copyright (c) 2008 James Stewart, released under the MIT license
http://jystewart.net/process/