Series List Tag

series.rb

# Series List Tag
#
# The original plugin was created by R.J. Lorimer and is available here:
# https://github.com/realjenius/site-samples/blob/master/2012-11-04-jekyll-series-list-2/series_tag.rb
#
# The modifications include:
#   - Using a data file (series.yml) to add more detail to the series
#   - Modified the output of the tag to look the way I wanted it to

module Jekyll
  
  class SeriesTag < Liquid::Tag
    def initialize(tag_name, params, tokens)
      super
    end

    def render(context)
      site = context.registers[:site]
      page_data = context.environments.first["page"]
      series = site.data['series']
      series_name = page_data['series']
      series_image = ""
            
      if !series_name
        puts "Unable to find series name for page: #{page.title}"
        return "<!-- Error with series tag -->"
      end
      
      series.each do |s|
        if s['name'] == series_name[0]
          series_image = "<img src='#{s['image']}' title='#{series_name[0]}' alt='#{series_name[0]}'>\n" if s['image']
          if s['copyright']
            series_image = "<figure>\n#{series_image}\n<figcaption>#{s['copyright']}</figcaption>\n</figure>"
          end
        end
      end

      all_entries = []
      site.posts.each do |p|
        if p.data['series'] == series_name
          all_entries << p
        end
      end

      all_entries.sort_by { |p| p.date.to_f }

      text = "<div class='series_list'>\n"
      text += "#{series_image}"
      list = "<ol>\n"
      all_entries.each_with_index do |post, idx|
        list += "<li>"
        if post.data['title'] == page_data['title']
          list += "#{post.data['title']}"
        text += "<h4>#{post.data['series'][0]}</h4>"
        else
          list += "<a href='#{post.url}'>#{post.data['title']}</a>"
        end
        list += "</li>\n"
      end
      text += list += "</ol>\n</div>\n"
      
    end
  end
end

Liquid::Template.register_tag('series_list', Jekyll::SeriesTag)