Meta override column setter to support Rich Picker submitting images as path strings rather than File objects.

carrier_wave_sanitizer.rb

# lib/rich/carrier_wave_sanitizer.rb

module Rich
  class CarrierWaveSanitizer
    def initialize(ar_object, column, path_string)
      @ar_object   = ar_object
      @column      = column
      @path_string = path_string
    end

    def sanitize_and_set
      return if @path_string.blank? || same_filename_as_persisted?

      set_file_from_path_string
    end

    private

    def same_filename_as_persisted?
      @path_string == @ar_object.send(@column).file.try(:filename)
    end

    def set_file_from_path_string
      if CarrierWave::Uploader::Base.storage == CarrierWave::Storage::File
        file_storage_set_upload
      elsif CarrierWave::Uploader::Base.storage == CarrierWave::Storage::Fog
        fog_storage_set_upload
      end
    end

    def file_storage_set_upload
      if File.exists?(absolute_image_path)
        @ar_object.send("#{@column}_without_sanitization=", File.open(absolute_image_path))
      end
    end

    def fog_storage_set_upload
      @ar_object.send("remote_#{@column}_url=", @path_string)
    end

    def absolute_image_path
      @absolute_image_path ||= File.join(resource_base_path, @path_string)
    end

    def resource_base_path
      Rails.env.test? ? "" : Rails.root.join("public")
    end
  end
end

carrier_wave_sanitizer_spec.rb

# spec/lib/rich/carrier_wave_sanitizer_spec.rb

require 'spec_helper'

describe Rich::CarrierWaveSanitizer do
  def image_path(filename)
    Rails.root.join("spec", "fixtures", "images", filename).to_s
  end

  let(:image_filename)  { "serve_hero.png" }
  let(:image_file)      { File.new(image_path(image_filename)) }

  let!(:subject)        { create(:hero_image_component, :image => image_file) }

  describe "#sanitize_and_set" do
    it "does not modify the AR object if value is blank" do
      lambda {
        subject.image = ""
      }.should_not change(subject, :image)
    end

    it "does not modify the AR object value is set to same filename as persisted" do
      lambda {
        subject.image = image_filename
      }.should_not change(subject, :image)
    end

    context "with a new non-blank value" do
      it "changes changed status on AR object if value is valid" do
        lambda {
          subject.image = image_path("housing_property.jpg")
        }.should change(subject, :changed).from([]).to(["image"])
      end

      context "when storage is File" do
        before { CarrierWave::Uploader::Base.storage = CarrierWave::Storage::File }
        after  { CarrierWave::Uploader::Base.storage = CarrierWave::Storage::File }

        it "stores the new file when storage type is File" do
          subject.image.file.filename.should == "serve_hero.png"

          subject.image = image_path("housing_property.jpg")

          subject.image.file.filename.should == "housing_property.jpg"
        end
      end

      context "when storage is Fog" do
        before { CarrierWave::Uploader::Base.storage = CarrierWave::Storage::Fog }
        after  { CarrierWave::Uploader::Base.storage = CarrierWave::Storage::File }

        it "sets the remote column url when storage type is Fog" do
          subject.image.file.filename.should == "serve_hero.png"

          subject.should_receive("remote_image_url=").with(image_path("housing_property.jpg"))

          subject.image = image_path("housing_property.jpg")
        end
      end
    end
  end
end

rich_picker_field.rb

# config/initializers/rich_picker_field.rb

# modifies the column setter to convert a path as string
# into a File object like multi-part forms submit.
# This is needed to work with CarrierWave uploaders
#
# Example:
# mount_uploader :image
# rich_picker_field :image

unless ActiveRecord::Base.respond_to?(:rich_picker_field)
  module RichPickerField
    def rich_picker_field(column)
      define_method "#{column}_with_sanitization=" do |path_string|
        rich_sanitizer = Rich::CarrierWaveSanitizer.new(self, column, path_string)

        rich_sanitizer.sanitize_and_set
      end

      self.send(:alias_method_chain, :"#{column}=", :sanitization)
    end
  end

  ActiveRecord::Base.extend(RichPickerField)
end