Ruby block cannot seem to access local scope variables

I'm writing a function that reads in an answer key, creates a question, and then associates the right answer with that questions. Here's my function:

def self.save_images_in_dir(dir)
  answer_key_file = Dir.glob(dir+"/*.{rtf,txt}").first
  answer_key = Array.new
  if answer_key_file
    puts "found key"
    File.open(answer_key_file, "r") do |infile|
        while (line = infile.gets)
            if line.match(/^\d+[.]\s+/)
              num = line.match(/\d+/)
              answer = line.gsub(/\d+[.]\s+/,"")  # Take out the 1. 
              answer.chomp!
              answer_key.push(answer.to_s)#answer_key[num.to_s]=answer.to_s
              puts "number #{num} is #{answer.to_s}"
            end
        end
    end
  end


  images = Dir.glob("#{dir}*.{png,jpeg,jpg,gif}").sort_by {|file| File.ctime(file) }

  counter = 0 

  answer_key.each do |q|
    puts "before entering: #{q}"
  end
  images.each do |img|
    q = self.new
    q.tags = get_tags(img)
    q.correct_answer = answer_key[coun开发者_运维问答ter]
    puts "---------Answer is:#{answer_key[counter]}--------\n"
    q.photo = File.open(img)


    if q.correct_answer.nil?
      puts "answer is nil"
    end

    counter = counter + 1 
  end
end

and here's a snippet of the output right before it enters the images.each block.

before entering: D

before entering: A

before entering: A

before entering: C

before entering: A

found key

---------Answer is:--------

answer is nil

Does anyone know why answer_key would "reset", and, furthermore, why answer_key.count would return 0 when evaluated within the images block? I understand that blocks should inherit the local scope from where they are called...any reason why answer_key would not be passed?

The mistake must be somewhere else, this code should work.

Write a few unit tests and refactor this method, it's trying to do too many things.

Also, when you loop over the images, you can get rid of counter and use each_with_index instead.