December 25, 2009

SmugMug

Note 2023-01-02 – This is an old post. It’s likely nothing here works anymore.

Updated 2010-04-04 – The regex in the to_html methos was updated again to do an even better job of preserving whitespace.

Updated 2010-03-21 – The regex in the to_html method on the SmugMug class was updated to preserve whitespace.

Up until now to post photos from SmugMug I’ve crafted the link and image markup by hand, which is pretty tedious and prone to error. Today I ginned up an extension to Markdown (RDiscount, really) that allows automatic generation of the markup from the image title and URL. Here’s how it works:

The first step is to create a new Hobix entry class (located in BLOG_ROOT/lib/local.rb):

module Hobix
  # Entries that use Markdown for formatting and automatically handle SmugMug
  # photos.
  class SmugMugEntry < Entry
    # Use SmugMug
    def self.text_processor
      SmugMug
    end

    # The YAML type for this entry class.
    def to_yaml_type
      "!goterkyourself.com,2009/SmugMugEntry"
    end

    # Register with the YAML engine.
    YAML::add_domain_type('goterkyourself.com,2009', 'SmugMugEntry') do |type, val|
      self.maker(val)
    end
  end
end

Now, any Hobix entry created with the type goterkyourself.com,2009/SmugMugEntry will use the SmugMug photo processor. All that remains now is to define the SmugMug class, which does the heavy lifting. This class is nested inside Hobix::SmugMugEntry:

# A SmugMug text processor that wraps Markdown with SmugMug specific
# capabilities.
#
# The syntax is:
#
#   $[Image Caption](Image URL)
#
#   i.e.: $[Bob Swimming](http://account.smugmug.com/Some/Category/1234567_abc12#123456789_AaBbC)
#
# Note that, for simplicity's sake, a SmugMug image blob must be on its
# own line
#
class SmugMug < RDiscount
  def to_html
    # Create a temporary string for the replacement so @text doesn't get
    # mangled.
    text = @text

    # Replace
    if text and not text.empty?
      text.gsub!(/^([ \t]*)\$\[(.*)\]\((.*)\)([ \t]*)$/) do |match|
        begin
          caption = $2
          image_url = $3
          image_id = image_url.split("#")[1]
          image_uri = URI.parse(image_url)

          raise "Missing image ID" if image_id.nil? or image_id.empty?

          "#{$1}" +
          "<a href=\"#{image_url}\">" +
            "<img src=\"http://#{image_uri.host}/photos/#{image_id}-640x640.jpg\" "+
                 "alt=\"#{caption}\" " +
                 "title=\"#{caption}\" " +
                 "class=\"photo\"/>" +
          "</a>" +
          "#{$4}"
        rescue
          # Just return the match on poorly formatted image blobs.
          $stderr.puts "Bad SmugMug blob: #{match}"
          match
        end
      end
    end

    m = RDiscount.new(text)
    m.to_html
  end
end

Once this is in place $[Amelie in her sheep hat!](http://gty.smugmug.com/Children/Amelie/7135981_oYtj9#705169136_SeMGC) becomes:

Amelie in her sheep hat!