Find paperclip meta for images without meta

gistfile1.rb

Image.where(attachment_meta: nil).each do |img|

    meta = {}

    Image.attachment_definitions[:attachment][:styles].merge({:original => nil}).keys.each do |style|
      url = img.attachment.url(style)
      uploaded_file = URI.parse(url)

      begin
        file = Paperclip.io_adapters.for(uploaded_file)
        geo = Paperclip::Geometry.from_file file
        meta[style] = {:width => geo.width.to_i, :height => geo.height.to_i, :size => file.size }
      rescue Paperclip::Errors::NotIdentifiedByImageMagickError => e
        meta[style] = {}
      end
    end

    unless meta == {}
      img.send("attachment_meta=", img.attachment.send(:meta_encode, meta))
      img.class.where(img.class.primary_key => img.id).update_all({ "attachment_meta" => img.attachment.send(:meta_encode, meta) })
    end
    
end