Is it possible to render blob images in a prawn document?

问题

I´m willing to use Gruff to render some graphics inside prawn documents.

I want to avoid the delay of writing images to the disk only for them to be read by Prawn.

Gruff offers the to_blob method that renders the graph image as a blob in memory, but looking at the prawn manual image section, it only gives us a way to render images directly from files.

Am I missing something? Is there a way to render it from memory?

回答1:

You should be able pass the image data as a StringIO

require 'stringio'
require 'pdf'

Prawn::Example.generate("foo.pdf") do |pdf|
  data = StringIO.new(render_my_image_to_a_string)
  pdf.image(data)
end 

来源：https://stackoverflow.com/questions/13769539/is-it-possible-to-render-blob-images-in-a-prawn-document