旋转附有回形针的图像

Question

We have an AR model with an avatar attached using Paperclip (4.2.0). We like to allow users to rotate this image, but I'm having a lot of difficulty making it work. My code looks like:

module Paperclip
  class Rotator < Thumbnail
    def initialize(file, options = {}, attachment = nil)
      options[:auto_orient] = false
      super
    end

    def transformation_command
      if rotate_command
        "#{rotate_command} #{super.join(' ')}"
      else
        super
      end
    end

    def rotate_command
      target = @attachment.instance
      if target.rotation.present?
        " -rotate #{target.rotation}"
      end
    end
  end
end

class User < ActiveRecord::Base
  has_attached_file :avatar, {
    styles: {
      small: ['72x72#', :png]
    },
    processors: [:rotator]
  }
  attr_accessor :rotate
end

And I'm trying to rotate the image by doing:

user.rotate = 90
user.avatar.reprocess!

I can see the -rotate 90 option being passed to convert, but it doesn't do anything. Has anyone managed to get this working using paperclip?

Answer 1

Replace target.rotation with target.rotate and add a trailing whitespace to the rotate_method did the trick for me.

module Paperclip
  class Rotator < Thumbnail
    def transformation_command
      if rotate_command
         rotate_command + super.join(' ')
      else
        super
      end
    end

    def rotate_command
      target = @attachment.instance
      if target.rotate.present?
        " -rotate #{target.rotate} "
      end
    end
  end
end

class User < ActiveRecord::Base
  has_attached_file :avatar, {
    styles: {
      small: ['72x72#', :png]
    },
    processors: [:rotator]
  }
  attr_accessor :rotate
end