Rails Active Storage render tiny image as base64

Question

I want to take an image that has already been uploaded and render the image as a small variant, then output that as a base 64 string.

I cannot seem to get the transformed image, I keep getting the original unprocessed image when I try this:

image.attachment.variant( resize_to_fill: [10, 10], convert: :png ).processed.blob.open do |tempfile|
  puts 'data:image/png;base64,' + Base64.strict_encode64(tempfile.read)
end

This is returning the data as the full image, not the 10x10 tiny square image. It seems like calling .blob on it returns the original image and not the processed one.

Answer 1

Try this:

  variation = ActiveStorage::Variation.new(resize_to_fit: [10, 10])

  image.open do |input|
    variation.transform(input, format: "png") do |output|
      puts 'data:image/png;base64,' + Base64.strict_encode64(output.read)
    end
  end