Extract ajax upload and destroy_upload actions from images and documents controllers and place them at new controllers to manage direct uploads

app/models/direct_upload.rb

@@ -1,27 +1,53 @@
 class DirectUpload
   include ActiveModel::Validations
+  include ActiveModel::Conversion
+  extend ActiveModel::Naming
 
-  attr_accessor :resource, :resource_type, :resource_id, :resource_relation,
-                :attachment, :cached_attachment
+  attr_accessor :resource, :resource_type, :resource_id,
+                :relation, :resource_relation,
+                :attachment, :cached_attachment, :user
 
   validates_presence_of :attachment, :resource_type, :resource_relation
   validate :parent_resource_attachment_validations,
            if: -> { attachment.present? && resource_type.present? && resource_relation.present? }
 
+  def save_attachment
+    @relation.attachment.save
+  end
+
+  def destroy_attachment
+    @relation.attachment.destroy
+  end
+
+  def persisted?
+    false
+  end
+
+  def initialize(attributes = {})
+    attributes.each do |name, value|
+      send("#{name}=", value)
+    end
+
+    if @resource_type.present?
+      @resource = @resource_type.constantize.find_or_initialize_by(id: @resource_id)
+    end
+
+    if @resource.class.reflections[@resource_relation].macro == :has_one
+      @relation = @resource.send("build_#{resource_relation}", attachment: @attachment, cached_attachment: @cached_attachment)
+    else
+      @relation = @resource.send(resource_relation).build(attachment: @attachment, cached_attachment: @cached_attachment)
+    end
+
+    @relation.user = user
+  end
+
+  private
+
   def parent_resource_attachment_validations
-    # Proposal or Budget::Investment
-    resource = resource_type.constantize.find_or_initialize_by(id: resource_id)
+    @relation.valid?
 
-    # Document or Image
-    relation = if resource.class.reflections[resource_relation].macro == :has_one
-                 resource.send("build_#{resource_relation}", attachment: attachment)
-               else
-                 resource.send(resource_relation).build(attachment: attachment)
-               end
-    relation.valid?
-
-    if relation.errors.has_key? :attachment
-      errors[:attachment] = relation.errors[:attachment]
+    if @relation.errors.has_key? :attachment
+      errors[:attachment] = @relation.errors[:attachment]
     end
   end