Question

I’ve been fighting this for some time now, and your help will certainly be of much appreciation.

I’ve built a method to sign pdf documents which you can find here, and now am only one step away from signing my file.

I would like to do this asynchronously, but first i would need to understand how to do it synchronously.

So I try 2 different approaches, the after post_process :

after_post_process do |receipt|
    if receipt.receipt_file_changed?

      require 'aws-sdk'
          logger.debug("RECEIPT ID: #{self.inspect}")
          file = receipt.receipt_file.queued_for_write[:original]
          s3=AWS::S3.new(
          access_key_id: S3_CONFIG["access_key_id"],
          secret_access_key: S3_CONFIG["secret_access_key"])
          bucket_name = S3_CONFIG["bucket"]

          b = s3.buckets[bucket_name]
          filen = File.basename(file.path)
          outputF = "original/teste.pdf"

          o = b.objects[outputF]
          o.write(file: file.path)

    end
  end

where i wanted to be able to send the file to a path something like /original/1/myfilename.pdf where 1 would be my receipt_id (and is null at the time of the after post_process).

I then tried a different approach with after_save, but receipt_file.to_file(:original) is not a valid call…

after_save do |receipt|
    if receipt.receipt_file_changed?

      require 'aws-sdk'
          logger.debug("RECEIPT ID: #{receipt.inspect}")

          s3=AWS::S3.new(
          access_key_id: S3_CONFIG["access_key_id"],
          secret_access_key: S3_CONFIG["secret_access_key"])
          bucket_name = S3_CONFIG["bucket"]

          b = s3.buckets[bucket_name]
          filen = File.basename(receipt_file_file_name)
          outputF = "original/teste.pdf"

          o = b.objects[outputF]
          o.write(file: receipt.receipt_file.to_file(:original))

    end
  end

How can i get the file and upload it back again to S3 ?

Edit

After some research i read how we can load a file from Amazon, and now the problem is that my file content is empty…What am i doing wrong?

after_save do |receipt|
    if receipt.receipt_file_changed?

      require 'aws-sdk'

          logger.debug("I was here inside after_save")
          s3=AWS::S3.new(
          access_key_id: S3_CONFIG["access_key_id"],
          secret_access_key: S3_CONFIG["secret_access_key"])
          bucket_name = S3_CONFIG["bucket"]

          b = s3.buckets[bucket_name]
          filen = File.basename(receipt_file_file_name)
          logger.debug("Filename is #{filen}")
          path = "original/#{receipt.id}/#{filen}"
          o = b.objects[path]

          require 'tempfile'

          ext= File.extname(filen)

          file = Tempfile.new([File.basename(filen,ext),ext], :encoding => 'ascii-8bit')
          # streaming download from S3 to a file on disk

          begin
            o.read do |chunk|
                file.write(chunk)
            end
          end
          file.close

          logger.debug("File is #{file.inspect}")

          o.write(file: signPdf(file).path)
          file.unlink

    end
  end

Answer 1

After splitting this problem in pieces, i noticed the real problem was within the process of download and writing to local disk. So i asked this question, and reached for a workaround.
In the end got this code for the after save :

  after_save do |receipt|
    if receipt.receipt_file_changed? && !@receipt.receipt_file.url[".pdf"] 

      require 'aws-sdk'

          s3=AWS::S3.new(
          access_key_id: S3_CONFIG["access_key_id"],
          secret_access_key: S3_CONFIG["secret_access_key"])
          bucket_name = S3_CONFIG["bucket"]

          b = s3.buckets[bucket_name]
          filen = File.basename(receipt_file_file_name)

          path = "original/#{receipt.id}/#{filen}"
          o = b.objects[path]

          require 'open-uri'
          require 'tempfile'

          ext= File.extname(filen)
          tfile = Tempfile.new([File.basename(filen,ext),ext])
          begin
            open(tfile.path,"wb") do |file|
                file << open(receipt.receipt_file.url,:ssl_verify_mode => OpenSSL::SSL::VERIFY_NONE).read
                o.write(file: signPdf(file).path, :acl => :public_read)
            end
          ensure
            tfile.close!
          end

    end
  end