Information Technology Dark Side

One of my users recently complained (rightly so) that my limit on photo sizes of 2MB meant they had to re-size every photo before uploading them because almost no modern cameras create photo files that small. So he requested that I re-size them on the fly the way our cell phones do when we send photos via text.

I really only wanted to re-size photos larger than 2MB and leave smaller photos alone. This turned out to be pretty straightforward – the only part that took some experimentation was how to leave the smaller photos alone. It turns out that if you just return an empty string for the style, paperclip will leave the original alone. Here’s the code.

class TroopPhoto < ActiveRecord::Base
  belongs_to :troop
  belongs_to :photo_album
  
  has_attached_file :photo,
    :styles => {
     riginal => Proc.new { |instance| instance.resize }, #stupid emoticon. That is colon original! 
    :large => "800x800#",
    :medium => "240x160#",
    :small => "100x100#"
    },
    :storage => :s3,
    :s3_credentials => "#{Rails.root}/config/s3.yml"
    
  attr_protected :photo_file_name, :photo_content_type, :photo_file_size, :troop_id, :photo_album_id
  
  validates_attachment_presence :photo
  validates_attachment_size :photo, :less_than => 5.megabytes, :message => "Photo size exceeds size limitation of 5MB"
  
  def resize
    if self.photo_file_size > 2000000
      "2400x2400#"
    else
      ""
    end
  end
end

Someone is probably going to point out that 2400 x 2400 is quite a bit smaller than 2MB and I could probably resize anything larger than 1MB to 2400 x 2400 without causing problems.

My response is … yup. I’m gonna play with it a bit to see what the best cutoff size is. But this works for now.

Stumble it!