active admin handle many assets

gistfile1.txt

f.inputs "Product images" do
  f.has_many :assets do |p|
    p.input :asset, :as => :file, :label => "Image",:hint => p.object.asset.nil? ? p.template.content_tag(:span, "No Image Yet") : p.template.image_tag(p.object.asset.url(:thumb))
    p.input :_destroy, :as=>:boolean, :required => false, :label => 'Remove image'
  end 
end

f.inputs "Product details" do
  f.input :category, :label => "Category", :hint => "Select one category"
  f.input :height
  f.input :width
  f.input :depth
  f.input :color, :label => "Color", :hint => "Select one color"
  f.input :sku, :label => "SKU"
  f.input :price
end
f.buttons