Images to gallery upload params

book_form.html.erb

# form to add images to the gallery
<%= f.simple_fields_for :gallery do |builder| %>
    <%= builder.input :name %>
    <%= render 'galleries/form', :f => builder %>
<% end %>

books_controller.rb

def book_params
  params.require(:book).permit(:title, :synopsis, :body, :age, :publisher, :jacket_cover, :story_id, :author_id, :school, schools_attributes: [:id, :school, :address, :school_name, :website, :_destroy], author_attributes: [:name,:biography], gallery_attributes: [:name, images: [ :image[:file] ] ] )
end

gallery_form.html.erb

<%= f.simple_fields_for :images, :wrapper => 'inline' do |builder| %>
  <%= link_to_add_association 'add image', f, :images, :render_options => {:wrapper => 'inline' }, :class => 'fa fa-plus' %>
<% end %>

params

{"utf8"=>"✓", 
"authenticity_token" => "hZQNoChpQ5gl+sXOZZzo1Tjo5HODfiDcmrBA8LXn4w0=", 
"book" => { 
	"jacket_cover"=>#<ActionDispatch::Http::UploadedFile:0x00000103c63370 @tempfile=#<File:/var/folders/mf/srx7jt8s2rdg0mn5hr98cvz80000gn/T/RackMultipart20140929-30270-92ugm5>, @original_filename="BmYbsf3CYAAxVJG.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"book[jacket_cover]\"; filename=\"BmYbsf3CYAAxVJG.jpg\"\r\nContent-Type: image/jpeg\r\n">, 
	"title" => "A booker book", 
	"synopsis" => "<p>z`xx`zz~X`X</p>\r\n", 
	"body" => "<p>`X~ZX~`Xx`</p>\r\n", 
	"age" => "11-14", 
	"publisher" => "Thames & Hudson", 
	"schools_attributes" => { 
		"0" => {
			"school_name"=>"a school", 
			"address"=>"49 lambs conduit street london wc1n 3ng"}
		}, 
	"author_id"=>"24", 
	"gallery_attributes" => {
		"name" => "the album", 
		"images_attributes" => { 
			"1412002788629" => { "file"=>#<ActionDispatch::Http::UploadedFile:0x0000010a921480 @tempfile=#<File:/var/folders/mf/srx7jt8s2rdg0mn5hr98cvz80000gn/T/RackMultipart20140929-30270-1lqwnsd>, @original_filename="46246205_1caa2bcb16_o.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"book[gallery_attributes][images_attributes][1412002788629][file]\"; filename=\"46246205_1caa2bcb16_o.jpg\"\r\nContent-Type: image/jpeg\r\n">}, 

			"1412002794270" => { "file"=>#<ActionDispatch::Http::UploadedFile:0x0000010a91ab30 @tempfile=#<File:/var/folders/mf/srx7jt8s2rdg0mn5hr98cvz80000gn/T/RackMultipart20140929-30270-ebp2lx>, @original_filename="BmYbsf3CYAAxVJG.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"book[gallery_attributes][images_attributes][1412002794270][file]\"; filename=\"BmYbsf3CYAAxVJG.jpg\"\r\nContent-Type: image/jpeg\r\n">}
		}
	}

},
"commit"=>"Create Book", "action"=>"create", "controller"=>"books"
}