Parsing an Email Attachment w Paperclip - Possible w/o a tempfile? - ruby-on-rails

Question

My rails 3 app on heroku receives incoming emails. I want to be able to accept attachments but can't get rails to process the attachments without erroring.
The ideal would be to pass the attachment provided by ActionMailer.
message_all = Mail.new(params[:message])
message_all.attachments.each do |a|
attachments.each do |a|
.attachments.build(
:attachment => a
)
end
end
It errors with: NoMethodError (undefined methodrewind' for #)`
Where attachments is a model, with attachment is paperclip
Ideas y? Is there a different way to pass the attachment = a , to paperclip?
I tried another approach, creating a tempfile:
tempfile = File.new("#{Rails.root.to_s}/tmp/#{a.filename}", "w+")
tempfile << a.body
tempfile.puts
attachments.build(
:attachment => File.open(tempfile.path) )
The problem with the tempfile is files without extentions "blah" instead of "blah.png" are breaking paperclip which is why I want to avoid the tempfile. and creating Identity errors, imagemagick doesn't know what they are w/o the ext.
hugely appreciate any advice on this.

Answer 1

The problem with the methods that you are using is that they don't contain all of the necessary information for paperclip like the content type and the original filename. I wrote a blog post about this a while back and how you could fake the format and use an email attachment as a paperclip attachment.
The bottom line was to do this:
file = StringIO.new(attachment)
file.class.class_eval { attr_accessor :original_filename, :content_type }
file.original_filename = attachment.filename
file.content_type = attachment.mime_type