Add image in pdf using Prawn

问题

I've a problem for adding images into a PDF using Prawn as pdf generator. I'm trying to add image using the following code:

def header
  text "something"
  image "#{Prawn::DATADIR}/images/logo_small.png"
end

But app replies to me with the following error:

 uninitialized constant Prawn::DATADIR

Where is the mistake?

P.S. My app is running on Rails 3.1 & Ruby 1.9.2.

回答1:

Prawn::DATADIR is new, it has been introduced recently about 2 or 3 months ago. Previously one would have used Prawn::BASEDIR/data instead. If you are using the current 0.12.0 version of the gem, you should stick with Prawn::BASEDIR/data. If you are using Rails 3.1, you can also put your image in the asset directory and use "#{Rails.root}/app/assets/images/logo_small.png"

来源：https://stackoverflow.com/questions/9565412/add-image-in-pdf-using-prawn