adapter.js

Case.RESTAdapter = DS.RESTAdapter.extend({
  serializer: Case.RESTSerializer,

  createRecord: function(store, type, record) {
    if(type == 'Case.VehiclePhoto') {
      this.createPhotoRecord(store, type, record);
    } else {
      var root = this.rootForType(type);

      var data = {};
      data[root] = this.serialize(record, { includeId: true });

      this.ajax(this.buildURL(root), "POST", {
        data: data,
        context: this,
        success: function(json) {
          Ember.run(this, function(){
            this.didCreateRecord(store, type, record, json);
          });
        },
        error: function(xhr) {
          this.didError(store, type, record, xhr);
        }
      });
    }
  },

  createPhotoRecord: function(store, type, record) {
    var root = this.rootForType(type), json = {};

    console.log(record);
    var data = new FormData();
    console.log(record.get('vehicleId'));
    data.append('vehicle_id', record.get('vehicleId'))
    data.append('name', record.get('name'));
    data.append('image', record.get('image'));

    this.fileAjax(this.buildURL(root), "POST", {
      data: data,
      context: this,
      success: function(preJSON) {
        console.log('success');
        json[root] = preJSON;
        this.didCreateRecord(store, type, record, json);
      }
    });
  },

  fileAjax: function(url, type, hash) {
    hash.url = url;
    hash.type = type;
    hash.contentType = false;
    hash.processData = false;
    hash.context = this;

    jQuery.ajax(hash);
  }
});

development.log

Started POST "/vehicle_photos" for 127.0.0.1 at 2013-04-16 00:25:42 -0700
Processing by VehiclePhotosController#create as */*
  Parameters: {"vehicle_id"=>"1001", "name"=>"crossing-the-gap.jpg", "image"=>"data:image/jpeg;base64,/9j/4RDaRXhpZgAATU0AKgAAAAgABwESAAMAAAABAAEAAAEaAAUAAAABAAAAYgEbAAUAAAABAAAAagEoAAMAAAABAAIAAAExAAIAAAAcAAAAcgEyAAIAAAAUAAAAjodpAAQAAAABAAAApAAAANAACvyAAAAnEAAK/IAAACcQQWRvYmUgUGhvdG9zaG9wIENTNSBXaW5kb3dzADIwMTI6MDQ6MTAgMTI6NTU6MTIAAAAAA6ABAAMAAAABAAEAAKACA...lots more base64 goodness"}
   (0.2ms)  BEGIN
  SQL (0.3ms)  INSERT INTO `vehicle_photos` (`created_at`, `image`, `name`, `position`, `updated_at`, `vehicle_id`) VALUES ('2013-04-16 07:25:43', NULL, 'crossing-the-gap.jpg', NULL, '2013-04-16 07:25:43', 1001)
   (1.8ms)  COMMIT
Redirected to http://case.dev/vehicle_photos/7
Completed 302 Found in 88ms (ActiveRecord: 6.0ms)

vehicle_photo.rb

class VehiclePhoto < ActiveRecord::Base
  attr_accessible :image, :vehicle_id, :position, :name
  belongs_to :vehicle

  mount_uploader :image, VehiclePhotoUploader
end

vehicle_photo_serializer.rb

class VehiclePhotoSerializer < ActiveModel::Serializer
  attributes :id, :vehicle_id, :image, :position, :name
end

vehicle_photo_uploader.rb

# encoding: utf-8

class VehiclePhotoUploader < CarrierWave::Uploader::Base

  # Include RMagick or MiniMagick support:
  # include CarrierWave::RMagick
  include CarrierWave::MiniMagick

  # Include the Sprockets helpers for Rails 3.1+ asset pipeline compatibility:
  # include Sprockets::Helpers::RailsHelper
  # include Sprockets::Helpers::IsolatedHelper

  # Choose what kind of storage to use for this uploader:
  storage :file
  # storage :fog

  # Override the directory where uploaded files will be stored.
  # This is a sensible default for uploaders that are meant to be mounted:
  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  # Provide a default URL as a default if there hasn't been a file uploaded:
  # def default_url
  #   # For Rails 3.1+ asset pipeline compatibility:
  #   # asset_path("fallback/" + [version_name, "default.png"].compact.join('_'))
  #
  #   "/images/fallback/" + [version_name, "default.png"].compact.join('_')
  # end

  # Process files as they are uploaded:
  # process :scale => [200, 300]
  #
  # def scale(width, height)
  #   # do something
  # end

  # Create different versions of your uploaded files:
  version :thumb do
    process :scale => [296, 150]
  end

  # Add a white list of extensions which are allowed to be uploaded.
  # For images you might use something like this:
  # def extension_white_list
  #   %w(jpg jpeg gif png)
  # end

  # Override the filename of the uploaded files:
  # Avoid using model.id or version_name here, see uploader/store.rb for details.
  # def filename
  #   "something.jpg" if original_filename
  # end

end

vehicle_photos_controller.rb

class VehiclePhotosController < ApplicationController
  # GET /vehicle_photos
  # GET /vehicle_photos.json
  def index
    @vehicle_photos = VehiclePhoto.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @vehicle_photos }
    end
  end

  # GET /vehicle_photos/1
  # GET /vehicle_photos/1.json
  def show
    @vehicle_photo = VehiclePhoto.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @vehicle_photo }
    end
  end

  # GET /vehicle_photos/new
  # GET /vehicle_photos/new.json
  def new
    @vehicle_photo = VehiclePhoto.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @vehicle_photo }
    end
  end

  # GET /vehicle_photos/1/edit
  def edit
    @vehicle_photo = VehiclePhoto.find(params[:id])
  end

  # POST /vehicle_photos
  # POST /vehicle_photos.json
  def create
    @vehicle_photo = VehiclePhoto.new(params.slice(:name, :vehicle_id, :image, :position))

    respond_to do |format|
      if @vehicle_photo.save
        format.html { redirect_to @vehicle_photo, notice: 'Vehicle photo was successfully created.' }
        format.json { render json: @vehicle_photo, status: :created, location: @vehicle_photo }
      else
        format.html { render action: "new" }
        format.json { render json: @vehicle_photo.errors, status: :unprocessable_entity }
      end
    end
  end

  # PUT /vehicle_photos/1
  # PUT /vehicle_photos/1.json
  def update
    @vehicle_photo = VehiclePhoto.find(params[:id])

    respond_to do |format|
      if @vehicle_photo.update_attributes(params[:vehicle_photo])
        format.html { redirect_to @vehicle_photo, notice: 'Vehicle photo was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: "edit" }
        format.json { render json: @vehicle_photo.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /vehicle_photos/1
  # DELETE /vehicle_photos/1.json
  def destroy
    @vehicle_photo = VehiclePhoto.find(params[:id])
    @vehicle_photo.destroy

    respond_to do |format|
      format.html { redirect_to vehicle_photos_url }
      format.json { head :no_content }
    end
  end
end