Thanks again Mladen Ilic for your help. For anyone that finds this, in order to build the multipart form-data, I needed to use the following to get the Octet-stream.
post_body << self.attachment_changes['pv_file'].attachable.read Hopefully we will eventually get a permanent/documented way to access the data pre-save. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-core+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-core/60f5cdae-bff3-4a49-bec1-89b6c54a1c0f%40googlegroups.com.
