Invoke the character string passed as an argument as a method with send

Overview

I learned how to use the send method, so make a note.

I had a form where I could attach up to two images, and I wanted to find out how big the post was, so I was trying to put in a log.

So I originally wrote the following code.

Before refactoring

validate :checking_image_size_over_limit

def checking_image_size_over_limit
  logging_image_size(image_first, 'first') if image_first.present?
  logging_image_size(image_second, 'second') if image_second.present?
end

def logging_image_size(image, number)
  if image&.size >= 5 * 1024 * 1024
    Rails.logger.info "[#{self.class.name}] Over 5MB of images (image_#{number})"
  end
end

I wanted to determine whether it was the first or the second, so I passed a string as the second argument and expanded it in the log message. However, I received a review from my senior and rewrote it, saying, "If so, you can use send with just one argument."

After refactoring

validate :checking_image_size_over_limit

def checking_image_size_over_limit
  logging_image_size('image_first') if image_first.present?
  logging_image_size('image_second') if image_second.present?
end

def logging_image_size(image)
  if send(image)&.size >= 5 * 1024 * 1024
    Rails.logger.info "[#{self.class.name}] Over 5MB of images (#{image})"
  end
end

Speaking of send, I only had the image of using it to dynamically switch methods, but I learned that it can also be used by invoking the character string passed as an argument as a method again.