Class: Paperclip::Thumbnail

Inherits:
Processor
  • Object
show all
Defined in:
lib/paperclip-smusher.rb

Instance Method Summary collapse

Instance Method Details

#make ⇒ Object

Performs the conversion of the file into a thumbnail. Returns the Tempfile that contains the new image.



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# File 'lib/paperclip-smusher.rb', line 6

def make
  src = @file
  conv = Tempfile.new([@basename, @format ? ".#{@format}" : ''])
  conv.binmode
  dst = Tempfile.new([@basename, @format ? ".#{@format}" : ''])
  dst.binmode

  begin
    parameters = []
    parameters << source_file_options
    parameters << ":source"
    parameters << transformation_command
    parameters << convert_options
    parameters << ":dest"

    parameters = parameters.flatten.compact.join(" ").strip.squeeze(" ")

    success = Paperclip.run("convert", parameters, :source => "#{File.expand_path(src.path)}#{'[0]' unless animated?}", :dest => File.expand_path(conv.path))
    if conv.size > 0
      format = begin
        Paperclip.run("identify", "-format %m :file", :file => "#{File.expand_path(conv.path)}[0]")
      rescue PaperclipCommandLineError
        ""
      end

      case format.strip
      when 'JPEG'
        # Part of libjpeg-progs deb package
        success = Paperclip.run('jpegtran', "-copy none -optimize -perfect :source > :dest", :source => File.expand_path(conv.path), :dest => File.expand_path(dst.path))
      when 'PNG'
        success = Paperclip.run('pngcrush', "-rem alla -reduce -brute :source :dest", :source => File.expand_path(conv.path), :dest => File.expand_path(dst.path))
      else
        dst = conv
      end
    end
  rescue Cocaine::ExitStatusError => e
    raise PaperclipError, "There was an error processing the thumbnail for #{@basename}" if @whiny
  rescue Cocaine::CommandNotFoundError => e
    raise Paperclip::CommandNotFoundError.new("Could not run the `convert` command. Please install ImageMagick.")
  rescue Exception => e
    Rails.logger.error "There was an error processing the thumbnail for #{@basename}. Check imagemagick, jpegtran and pngcrush installed."
    Rails.logger.error e.message
  end

  dst.size > 0 ? dst : conv
end