Jekyll Examples

author.html

<div class="byline author vcard">
  <a class="photo" href="{% render_author url %}">
    <img src="{% render_author avatar %}" alt="{{ page.author }}" title="{{ page.author }}">
  </a>
  <h2>{{ page.author }}</h2>
  <div class="author-bio">
    <p>{% render_author bio %}</p>
  </div>
</div>

custom_category_pages.rb

# If category is with questions...
if self.categories[index.data['category']].select { |post| post.categories[0] == 'questions' }.length != 0

  # Specify a unique folder for /categories based on post type. In this case, /questions/categories
  target_dir = '/' + GenerateCategories.category_dir(self.config['category_question_dir'], category)
 
  # Use a unique layout file for this post type. In this case, question_category_index.html
  index = CategoryIndex.new(self, self.source, target_dir, category, 'question_category_index.html')

  # Add category page to queue for export
  if index.render?
    self.pages << index
  end       

end

custom_category_pages2.rb

def write_category_indexes
  if self.layouts.key? 'blog_category_index'
    self.categories.keys.each do |category|
      next if RESTRICTED_CATEGORIES.include? category
      self.write_category_index(category)
    end

  # Throw an exception if the layout couldn't be found.
  else
    throw "No 'category_index' layout found."
  end
end

filter_excerpt.rb

module Jekyll
  class Post
    alias_method :original_to_liquid, :to_liquid
    def to_liquid
      original_to_liquid.deep_merge({
        'excerpt' => content.match('<!--more-->') ? content.split('<!--more-->').first : nil
      })
    end
  end
  
  module Filters
    def mark_excerpt(content)
      content.gsub('<!--more-->', '<p><span id="more"></span></p>')
    end
  end
end

filter_posts_and_categories.rb

module Jekyll
  module PostAndCategoryFilter
    RESTRICTED_CATEGORIES = ['blog', 'questions']

    # Returns back all categories related to a primary category
    # e.g. "blog" or "questions"
    def filter_categories_by_primary_category(posts)
      filtered = []
      for post in posts
        for post_category in post.categories
          filtered.push(post_category) unless RESTRICTED_CATEGORIES.include? post_category
        end
      end
      filtered.sort.uniq
    end
  end
end

Liquid::Template.register_filter(Jekyll::PostAndCategoryFilter)

generate_pagination.rb

module Jekyll
  class Page
    attr_accessor :dir
  end

  module Generators
    class Pagination < Generator
      # This generator is safe from arbitrary code execution.
      safe true

      # Generate paginated pages if necessary.
      #
      # site - The Site.
      #
      # Returns nothing.
      def generate(site)
        paginate(site, '/blog/index.html', 'blog')
        paginate_categories(site, '/blog/categories', 'blog_category_index.html', site.categories['blog'])
        paginate_categories(site, '/questions/categories', 'question_category_index.html', site.categories['questions'])
      end

      # Paginates the blog's posts. Renders the index.html file into paginated
      # directories, e.g.: page2/index.html, page3/index.html, etc and adds more
      # site-wide data.
      #
      # site - The Site.
      # page - The index.html Page that requires pagination.
      #
      # {"paginator" => { "page" => <Number>,
      #                   "per_page" => <Number>,
      #                   "posts" => [<Post>],
      #                   "total_posts" => <Number>,
      #                   "total_pages" => <Number>,
      #                   "previous_page" => <Number>,
      #                   "next_page" => <Number> }}
      def paginate(site, page_path, category)
        all_posts = site.site_payload['site']['categories'][category]

        page = site.pages.select do |page|
          path = page.dir + "/" + page.name
          path == page_path
        end.first

        pages = Pager.calculate_pages(all_posts, site.config['custom_paginate'].to_i)
        (1..pages).each do |num_page|
          pager = Pager.new(site, num_page, all_posts, pages, page)
          if num_page > 1
            newpage = Page.new(site, site.source, page.dir, page.name)
            newpage.pager = pager
            newpage.dir = File.join(page.dir, "page#{num_page}")
            site.pages << newpage
          else
            page.pager = pager
          end
        end
      end

      def paginate_categories(site, category_path, category_layout, posts)
        categories = []
        restricted_categories = ['blog', 'questions']

        for post in posts
          for post_category in post.categories
            categories.push(post_category) unless restricted_categories.include? post_category
          end
        end

        categories.sort!.uniq!
        
        for category in categories
          all_posts = site.site_payload['site']['categories'][category]

          page = site.pages.select do |page|
            path = page.dir + "/" + page.name
            path == category_path + "/" + category + "/index.html"
          end.first

          pages = Pager.calculate_pages(all_posts, site.config['custom_paginate'].to_i)
          (1..pages).each do |num_page|
            pager = Pager.new(site, num_page, all_posts, pages, page)
            if num_page > 1
              newpage = CategoryIndex.new(site, site.source, page.dir, category, category_layout)
              newpage.pager = pager
              newpage.dir = File.join(page.dir, "page#{num_page}")
              site.pages << newpage
            else
              page.pager = pager
            end
          end 
        end       
      end
    end
  end

  class Pager
    attr_reader :page, :per_page, :posts, :total_posts, :total_pages,
      :previous_page, :previous_page_path, :next_page, :next_page_path

    # Calculate the number of pages.
    #
    # all_posts - The Array of all Posts.
    # per_page  - The Integer of entries per page.
    #
    # Returns the Integer number of pages.
    def self.calculate_pages(all_posts, per_page)
      (all_posts.size.to_f / per_page.to_i).ceil
    end

    # Determine if the subdirectories of the two paths are the same relative to source
    #
    # source        - the site source
    # page_dir      - the directory of the Jekyll::Page
    # paginate_path - the absolute paginate path (from root of FS)
    #
    # Returns whether the subdirectories are the same relative to source
    def self.in_hierarchy(source, page_dir, paginate_path)
      return false if paginate_path == File.dirname(paginate_path)
      return false if paginate_path == Pathname.new(source).parent
      page_dir == paginate_path ||
        in_hierarchy(source, page_dir, File.dirname(paginate_path))
    end

    # Static: Return the pagination path of the page
    #
    # site     - the Jekyll::Site object
    # num_page - the pagination page number
    # target_page - the page where pagination is occurring
    #
    # Returns the pagination path as a string
    def self.paginate_path(site, num_page, target_page)
      return nil if num_page.nil?
      return target_page.url if num_page <= 1
      format = site.config['paginate_path']
      format = format.sub(':num', num_page.to_s)
      ensure_leading_slash(format)
    end

    # Static: Return a String version of the input which has a leading slash.
    #         If the input already has a forward slash in position zero, it will be
    #         returned unchanged.
    #
    # path - a String path
    #
    # Returns the path with a leading slash
    def self.ensure_leading_slash(path)
      path[0..0] == "/" ? path : "/#{path}"
    end

    # Static: Return a String version of the input without a leading slash.
    #
    # path - a String path
    #
    # Returns the input without the leading slash
    def self.remove_leading_slash(path)
      ensure_leading_slash(path)[1..-1]
    end

    # Initialize a new Pager.
    #
    # config    - The Hash configuration of the site.
    # page      - The Integer page number.
    # all_posts - The Array of all the site's Posts.
    # num_pages - The Integer number of pages or nil if you'd like the number
    #             of pages calculated.
    def initialize(site, page, all_posts, num_pages = nil, target_page)
      @page = page
      @per_page = site.config['custom_paginate'].to_i
      @total_pages = num_pages || Pager.calculate_pages(all_posts, @per_page)

      if @page > @total_pages
        raise RuntimeError, "page number can't be greater than total pages: #{@page} > #{@total_pages}"
      end

      init = (@page - 1) * @per_page
      offset = (init + @per_page - 1) >= all_posts.size ? all_posts.size : (init + @per_page - 1)

      @total_posts = all_posts.size
      @posts = all_posts[init..offset]
      @previous_page = @page != 1 ? @page - 1 : nil
      @previous_page_path = Pager.paginate_path(site, @previous_page, target_page)
      @next_page = @page != @total_pages ? @page + 1 : nil
      @next_page_path = Pager.paginate_path(site, @next_page, target_page)
    end

    # Convert this Pager's data to a Hash suitable for use by Liquid.
    #
    # Returns the Hash representation of this Pager.
    def to_liquid
      {
        'page' => page,
        'per_page' => per_page,
        'posts' => posts,
        'total_posts' => total_posts,
        'total_pages' => total_pages,
        'previous_page' => previous_page,
        'previous_page_path' => previous_page_path,
        'next_page' => next_page,
        'next_page_path' => next_page_path
      }
    end
  end
end

generate_sitemap_entry.rb

def entry(path, date, attrs, site)
  # Remove the trailing slash from the baseurl if it is present, for consistency.
  baseurl = site.config['url']
  baseurl = baseurl[0..-2] if baseurl=~/\/$/

  entry = "\n\t<url>\n\t\t<loc>#{baseurl}#{path}</loc>\n"
  entry += "\t\t<lastmod>#{date.strftime("%Y-%m-%d")}</lastmod>\n" unless date.nil?
  entry += attrs.map { |k,v| "\t\t<#{k}>#{v}</#{k}>" }.join("\n") + "\n\t</url>\n"
end

tag_author.rb

module Jekyll
  class AuthorTag < Liquid::Tag

    def initialize(tag_name, attribute, tokens)
      super
      @attribute = attribute
    end

    def render(context)
      authors = JSON.parse(IO.read('authors.json'))['authors']
      author_name = context.environments.first['page']['author']
      selected_author = authors.select { |author| author['name'] == author_name }
      selected_author[0][@attribute.strip!]
    end
  end
end

Liquid::Template.register_tag('render_author', Jekyll::AuthorTag)

got the same error as @circa1977 undefined method pager=' for nil:NilClass

I'm using excerpts with the method. It was already provided by jekyll so I didn't have to use the plugin. Any ideas on how I may remove images from the excerpts?

Hi there. I'm already using the plugin filter_posts_and_categories.rb and it works as intended. Thanks for sharing your plugin code.

Anyway, the generate_pagination.rb plugin seems to be very promising. However, I've tried to set it up but jekyll fails to serve and throws the following error:

generate_pagination.rb:87:in 'block (2 levels) in paginate_categories': undefined method 'pager=' for nil:NilClass (NoMethodError)

I've slightly modified the plugin so that it fits my site / blog set up.

So in config.yml I've place the following:

category_dir: "/blog/categories/"
category_portfolio_dir: "/projects/categories/" 

And here's the modified lines in the plugin's code

  def generate(site)
    paginate(site, '/blog/index.html', 'blog')
    paginate_categories(site, '/blog/categories', 'blog_category_index.html', site.categories['blog'])
    paginate_categories(site, '/portfolio/categories', 'portfolio_category_index.html', site.categories['projects'])
  end

Am I supposed to create blog_category_index.htmland portfolio_category_index.htmlor are these .html pages going to be generated by the plugin?

I'd really appreciate any thoughts regarding this issue. I would be great if Jekyll paginator could filter posts by type or category.