Using the imageable pattern for storing rails images eliminates dependencies on gems and makes adding more models more manageable.

There are some details about this pattern in the docs: http://guides.rubyonrails.org/association_basics.html#polymorphic-associations

Using refile, here's a rough set up:

Generate the Image model:

class CreateImages < ActiveRecord::Migration
  def change
    create_table :images do |t|
      t.string :file_id
      t.boolean :featured
      t.references :imageable, polymorphic: true, index: true
      t.timestamps null: false
    end
  end
end

Update the Image model:

class Image < ActiveRecord::Base
  attachment :file
  belongs_to :imageable, polymorphic: true
end

Add association

class Model < ActiveRecord::Base
  has_many :images, as: :imageable, dependent: :destroy
  accepts_attachments_for :images, attachment: :file
end

Using the fields in the add/edit form (using slim):

There are more details about the refile gem in the docs

.form-group
    = f.attachment_field :images_files, multiple: true, presigned: true, direct: true

Allow the files in the controller strong params:

params.require(:community).permit(:name, :description, :address, :city, :province, :postal_code, :status, images_files: [])

# The important item
images_files: []