jekyll-seo-tag/lib/jekyll-seo-tag.rb

require 'jekyll-seo-tag/filters'

module Jekyll
  class SeoTag < Liquid::Tag
    attr_accessor :context

    MINIFY_REGEX = /(>\n|[%}]})\s+(<|{[{%])/

    def render(context)
      @context = context
      output = template.render!(payload, info)

      output
    end

    private

    def payload
      {
        'seo_tag' => { 'version' => VERSION },
        'page'    => context.registers[:page],
        'site'    => context.registers[:site].site_payload['site']
      }
    end

    def info
      {
        registers: context.registers,
        filters: [Jekyll::Filters, JekyllSeoTag::Filters]
      }
    end

    def template
      @template ||= Liquid::Template.parse template_contents
    end

    def template_contents
      @template_contents ||= begin
        File.read(template_path).gsub(MINIFY_REGEX, '\1\2').chomp
      end
    end

    def template_path
      @template_path ||= begin
        File.expand_path './template.html', File.dirname(__FILE__)
      end
    end
  end
end

Liquid::Template.register_tag('seo', Jekyll::SeoTag)