Class: Inkcite::Minifier

Inherits:
Object
  • Object
show all
Defined in:
lib/inkcite/minifier.rb

Constant Summary collapse

IMAGE_CACHE =

Directory of optimized images

"images-optim"
MAXIMUM_LINE_LENGTH =

Maximum line length for CSS and HTML - lines exceeding this length cause problems in certain email clients.

800

Class Method Summary collapse

Class Method Details

.css(code, ctx) ⇒ Object 



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# File 'lib/inkcite/minifier.rb', line 11

def self.css code, ctx

  # Do nothing to the code unless minification is enabled.
  if minify?(ctx)

    # After YUI's CSS compressor started introducing problems into CSS3
    # animations, I've switched to a homegrown, extremely simple compression
    # algorithm for CSS.  Instead of messing with parameters, we're simply
    # eliminating whitespace.

    # Replace all line breaks with spaces
    code.gsub!(/[\n\r\f]/, ' ')

    # Remove whitespace at the beginning or ending of the code
    code.gsub!(/^\s+/, '')
    code.gsub!(/\s+$/, '')

    # Compress multiple whitespace characters into a single space.
    code.gsub!(/\s{2,}/, ' ')

    # Remove whitespace preceding or following open and close curly brackets.
    code.gsub!(/\s*([{};:])\s*/, "\\1")

    # Remove semicolons preceding close brackets.
    code.gsub!(';}', '}')

    # Certain versions of outlook have a problem with excessively long lines
    # so if this minified code now exceeds the maximum line limit, re-introduce
    # wrapping in spots where it won't break anything to do so - e.g. following
    # a semicolon or close bracket.
    if ctx.email? && code.length > MAXIMUM_LINE_LENGTH

      # Position at which a line break will be inserted at.
      break_at = 0

      # Work through the code injecting line breaks until either no further
      # breakable characters are found or we've reached the end of the code.
      while break_at < code.length
        break_at = code.rindex(/[;}]/, break_at + MAXIMUM_LINE_LENGTH) + 1
        code.insert(break_at, "\n") if break_at && break_at < code.length
      end

    end

  end

  code
end

.html(lines, ctx) ⇒ Object 



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# File 'lib/inkcite/minifier.rb', line 60

def self.html lines, ctx

  if minify?(ctx)

    # Will hold the assembled, minified HTML as it is prepared.
    html = ''

    # Will hold the line being assembled until it reaches the maximum
    # allowed line length.
    packed_line = ''

    lines.each do |line|
      next if line.blank?

      line.strip!

      ## Compress all in-line styles.
      #Parser.each line, INLINE_STYLE_REGEX do |style|
      #  style.gsub!(/: +/, ':')
      #  style.gsub!(/; +/, ';')
      #  style.gsub!(/;+/, ';')
      #  style.gsub!(/;+$/, '')
      #  "style=\"#{style}\""
      #end

      # If the length of the packed line with the addition of this line of content would
      # exceed the maximum allowed line length, then push the collected lines onto the
      # html and start a new line.
      if !packed_line.blank? && packed_line.length + line.length > MAXIMUM_LINE_LENGTH
        html << packed_line
        html << NEW_LINE
        packed_line = ''
      end

      packed_line << ' ' unless packed_line.blank?
      packed_line << line

    end

    # Make sure to get any last lines assembled on the packed line.
    html << packed_line unless packed_line.blank?

    html
  else
    lines.join(NEW_LINE)

  end

end

.images(email, force = false) ⇒ Object 



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# File 'lib/inkcite/minifier.rb', line 110

def self.images email, force=false

  images_path = email.image_dir
  cache_path = email.project_file(IMAGE_CACHE)

  # Check to see if there is an image optim configuration file.
  config_path = email.project_file(IMAGE_OPTIM_CONFIG_YML)
  config_last_modified = Util.last_modified(config_path)

  # If the image cache exists, we need to check to see if any images have been
  # removed since the last build.
  if File.exist?(cache_path)

    # Get a list of the files in the cache that do not also exist in the
    # project's images/ directory.
    removed_images = Dir.entries(cache_path) - Dir.entries(images_path)
    unless removed_images.blank?

      # Convert the images to fully-qualified paths and then remove
      # those files from the cache
      removed_images = removed_images.collect { |img| File.join(cache_path, img) }
      FileUtils.rm(removed_images)

    end

  end

  # Check to see if there are new or updated images that need to be re-optimized.
  # Compare existing images against both the most recently cached version and
  # the timestamp of the config file.
  updated_images = Dir.glob(File.join(images_path, '*.*')).select do |img|
    cached_img = File.join(cache_path, File.basename(img))
    cache_last_modified = Util.last_modified(cached_img)
    force || config_last_modified > cache_last_modified || Util.last_modified(img) > cache_last_modified
  end

  # Return unless there is something to compress
  return if updated_images.blank?

  FileUtils.mkpath(cache_path)

  # Check to see if there is an image_optim.yml file in this directory that
  # overrides the default settings.
  image_optim_opts = if config_last_modified > 0
    {
        :config_paths => [IMAGE_OPTIM_CONFIG_YML]
    }
  else
    {
        :allow_lossy => true,
        :gifsicle => { :level => 3 },
        :jpegoptim => { :max_quality => 50 },
        :jpegrecompress => { :quality => 1 },
        :pngout => false,
        :svgo => false
    }
  end

  image_optim = ImageOptim.new(image_optim_opts)

  # Copy all of the images that need updating into the temporary directory.
  # Specifically joining the images_path to the image to avoid Email's
  # image_path which may change it's directory if optimization is enabled.
  updated_images.each do |img|
    cached_img = File.join(cache_path, File.basename(img))
    FileUtils.cp(img, cached_img)
    image_optim.optimize_image!(cached_img)
  end

end

.js(code, ctx) ⇒ Object 



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# File 'lib/inkcite/minifier.rb', line 181

def self.js code, ctx
  minify?(ctx) ? js_compressor(ctx).compress(code) : code
end

.remove_comments(html, ctx) ⇒ Object 



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# File 'lib/inkcite/minifier.rb', line 185

def self.remove_comments html, ctx
  remove_comments?(ctx) ? html.gsub(HTML_COMMENT_REGEX, '') : html
end