image_helper.rb

module ImageHelper
  def image(name, alt, link = '')
    tmp = File.join(Dir.getwd, 'content')
    possible_paths = [
      File.join(tmp, @page.directory, 'images', name),
      File.join(tmp, 'images', name)
    ]
    file = possible_paths.find {|path| File.exists? path }
    file

    thumbnail = generate_thumbnail file
    w, h = image_size(thumbnail ? thumbnail : file)

    output = sprintf('<div class="image" style="width: %dpx;">!', w)
    output += (thumbnail ? thumbnail : file).sub(/^(.+?content)/, '')
    output += "(#{alt})"
    output += '!'
    output += ":#{link}" unless link.empty?
    if thumbnail
      output += "<div>"
      output += "<div class=\"enlarge\">!/images/enlarge.png!:#{file.sub(/^(.+?content)/, '')}</div>"
      output += "#{alt}</div>"
    end
    output += '</div>'

    output
  end

  private
  def generate_thumbnail(file)
    w, h = image_size file

    aspect = if w > 500
               '500'
             elsif h > 500
               'x500'
             end

    if aspect
      filename = File.basename(file)
      dirname = File.dirname(file)
      thumb_file = File.join(File.dirname(file), "thumb_#{File.basename(file)}")

      unless File.exists? thumb_file
        `convert -resize "#{aspect}" "#{file}" "#{thumb_file}"`
        unless $?.exitstatus == 0
          STDERR.puts "EO EO Error creating thumbnail!!"
          return nil
        end
      end

      return thumb_file
    end

    return false
  end

  def image_size(file)
    `/usr/bin/env identify -format "%w %h" "#{file}"`.split(' ').map{|x| x.to_i}
  end
end

Webby::Helpers.register(ImageHelper)