_books_form.html.erb

# form for books#create page
<%= simple_form_for(@book, :html => { :multipart => true }) do |f| %>
  <%= f.error_notification %>

  <div class="inputs">
  	<%= f.file_field :jacket_cover %>
    <%= f.input :title %>
    <%= f.input :synopsis, :as => :ckeditor, :label => false, :input_html => {  :ckeditor => { :toolbar => 'Full', :height => 400 } } %>
    <%= f.input :body, :as => :ckeditor, :label => false, :input_html => {  :ckeditor => { :toolbar => 'Full', :height => 400 } } %>
    <%= f.input :age %>
    <%= f.input :publisher %>
  </div>
  <%= f.simple_fields_for :author do |a| %>
	   <%= a.input :name %>
  	 <%= a.input :biography, :as => :ckeditor, :label => false, :input_html => {  :ckeditor => { :toolbar => 'Full', :height => 400 } } %>
  <% end %>

    <%= f.simple_fields_for :gallery do |builder| %>
      <%= render 'galleries/form', :f => builder %>
    <% end %>

  <div class="actions">
    <%= f.button :submit %>
  </div>
<% end %>

_galleries_form.html.erb

# form for galleries nested
  <div class="inputs">
  	<%#= f.simple_fields_for :image do |a| %>
    <%#= f.input :book_id %>
  		<%#= a.input_field :file, as: :file, multiple: true, name: 'image[file]' %>
  	<%# end %>
    <%= f.simple_fields_for :images do |builder| %>
      <%= render 'images/form', :f => builder %>
    <% end %>

  </div>

_images_form.html.erb

# form for images nested in galleries form
  <div class="inputs">
    <%#= f.input :file %>
    <%#= f.input_field :file, as: :file, multiple: true, name: 'image[file]' %>
    <%= f.file_field :file, multiple: true %>
  </div>

book.rb

# this will allow me to create a book it has one gallery
class Book < ActiveRecord::Base

	has_attached_file :jacket_cover, :styles => { :medium => "300x300>", :thumb => "100x100>" }, :default_url => "/images/:style/missing.png"
	validates_attachment_content_type :jacket_cover, :content_type => /\Aimage\/.*\Z/

	validates :jacket_cover, :title, :slug, :synopsis, :body, :age, :publisher, presence: true
	validates_uniqueness_of :title

	extend FriendlyId
	friendly_id :title, use: [:slugged, :finders]

	belongs_to :author
	has_one :gallery

	accepts_nested_attributes_for :author
	accepts_nested_attributes_for :gallery

	scope :available, ->{ where(available: true) }
	scope :unavailable, ->{ where(available: [nil, false]) }

end

books_controller.rb

class BooksController < ApplicationController
  before_action :set_book, only: [:show, :edit, :update, :destroy]
  before_filter :authenticate_user!, only: [:new, :edit, :update, :destroy]
  def index
    @books = Book.order('created_at DESC').all
  end

  # GET /books/1
  # GET /books/1.json
  def show
    @book = Book.friendly.find(params[:id])
    @gallery = @book.gallery
  end

  # GET /books/new
  def new
    @book = Book.new
    @book.build_author
    @gallery = @book.build_gallery 
    @gallery.images.build
  end


  def create
    #raise params.inspect
    @book = Book.new(book_params)

    #binding.pry

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

  def update
    respond_to do |format|
      if @book.update(book_params)
        format.html { redirect_to @book, notice: 'Book was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @book.errors, status: :unprocessable_entity }
      end
    end
  end

  def destroy
    @book.destroy
    respond_to do |format|
      format.html { redirect_to books_url }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_book
      @book = Book.friendly.find(params[:id])
    end

    def book_params
      params.require(:book).permit(:title, :synopsis, :body, :age, :publisher, :jacket_cover, author_attributes: [:name,:biography], gallery_attributes: [:name, :book_id, images_attributes:[] ] )
    end
end

galleries_controller.rb

class GalleriesController < ApplicationController
  before_action :set_gallery, only: [:show, :edit, :update, :destroy]

  def index
    @galleries = Gallery.all
  end

  def show
    @gallery = Gallery.find(params[:id])
    @images = @gallery.images
  end

  def new
    @gallery = Gallery.new
    #@image = @gallery.build_book 
    #@gallery.images.build
  end

  def edit
    @gallery.images.build
  end

  def create 
    @gallery = Gallery.new(gallery_params) 

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

  def destroy
    @gallery.destroy
    respond_to do |format|
      format.html { redirect_to galleries_url }
      format.json { head :no_content }
    end
  end

  private
    def set_gallery
      @gallery = Gallery.find(params[:id])
    end

    def gallery_params
      params.require(:gallery).permit(:name, :book_id, :images[], images_attributes: [:id, :file []])
    end
end

gallery.rb

# This is where the gallery data is handled and it has many images
class Gallery < ActiveRecord::Base

	belongs_to :books
	has_many :images
	accepts_nested_attributes_for :books
	accepts_nested_attributes_for :images, :allow_destroy => true

end

image.rb

# This is where an image object is created that belongs to a gallery where the :file is the paperclip object.
class Image < ActiveRecord::Base

	belongs_to :gallery

	has_attached_file :file, :styles => { :medium => "300x300>", :thumb => "100x100>" }, :default_url => "/images/:style/missing.png"
	validates_attachment_content_type :file, :content_type => /\Aimage\/.*\Z/

	# def files=(files = [])
 #    	files.each{|f| (@images ||= []) << images.create(file: f) }
 #  	end

end

images_controller.rb

class ImagesController < ApplicationController
  before_action :set_image, only: [:show, :edit, :update, :destroy]

  	def show
  		@image = Image.find(params[:id])
  	end

  	def index
  		@images = Image.all
  	end

  	def new
  		@image = Image.new
  	end

	def create
	  	@image = Image.new( image_params )
	end

	def edit
	end


  private
    # Use callbacks to share common setup or constraints between actions.
    def set_image
      @image = Image.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def image_params
      params.require(:image).permit(:file)
    end

end

log file for params

Parameters: {
	"utf8"=>"✓", 
	"authenticity_token"=>"BJhkDx7rCRMIlXQ6T9FskXZe7+fdYxj0qm+VnCaC51w=", 
	"book"=>{ 
		"jacket_cover" =>#<ActionDispatch::Http::UploadedFile:0x000001025d3128 
		@tempfile=#<File:/var/folders/mf/srx7jt8s2rdg0mn5hr98cvz80000gn/T/RackMultipart20140918-47766-1g9kyas>, @original_filename="559a7a477253d58f891f8e852162dfac.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"book[jacket_cover]\"; filename=\"559a7a477253d58f891f8e852162dfac.jpg\"\r\nContent-Type: image/jpeg\r\n">,
		"title"=>"zd szw wrwr", 
		"synopsis"=>"<p>cfdcrgcgrere</p>\r\n", 
		"body"=>"<p>rccgregrrgerereg</p>\r\n", 
		"age"=>"19", 
		"publisher"=>"Dove books", 
		"author_attributes"=>{
			"name"=>"zsdxfrrwg", 
			"biography"=>"<p>exffwfwefewewf</p>\r\n"}, 
		"gallery_attributes"=>{
			"images_attributes"=>{
  			"0"=>{
  				"file"=>[#<ActionDispatch::Http::UploadedFile:0x000001025d20e8 @tempfile=#<File:/var/folders/mf/srx7jt8s2rdg0mn5hr98cvz80000gn/T/RackMultipart20140918-47766-tk1rdb>, @original_filename="23ebb202a3655c6d0947251cce8625b6.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"book[gallery_attributes][images_attributes][0][file][]\"; filename=\"23ebb202a3655c6d0947251cce8625b6.jpg\"\r\nContent-Type: image/jpeg\r\n">, #<ActionDispatch::Http::UploadedFile:0x000001025d1ff8 @tempfile=#<File:/var/folders/mf/srx7jt8s2rdg0mn5hr98cvz80000gn/T/RackMultipart20140918-47766-j3ji7c>, @original_filename="559a7a477253d58f891f8e852162dfac.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"book[gallery_attributes][images_attributes][0][file][]\"; filename=\"559a7a477253d58f891f8e852162dfac.jpg\"\r\nContent-Type: image/jpeg\r\n">]
  			}
			}
		}
	}, "commit"=>"Create Book"

}
  
Unpermitted parameters: images_attributes