# encoding: utf-8
#
# Jekyll category page generator.
# http://recursive-design.com/projects/jekyll-plugins/
#
# Version: 0.2.4 (201210160037)
#
# Copyright (c) 2010 Dave Perrett, http://recursive-design.com/
# Licensed under the MIT license (http://www.opensource.org/licenses/mit-license.php)
#
# A generator that creates category pages for jekyll sites.
#
# To use it, simply drop this script into the _plugins directory of your Jekyll site. You should
# also create a file called 'category_index.html' in the _layouts directory of your jekyll site
# with the following contents (note: you should remove the leading '# ' characters):
#
# ================================== COPY BELOW THIS LINE ==================================
# ---
# layout: default
# ---
#
# <h1 class="category">{{ page.title }}</h1>
# <ul class="posts">
# {% for post in site.categories[page.category] %}
# <div>{{ post.date | date_to_html_string }}</div>
# <h2><a href="{{ post.url }}">{{ post.title }}</a></h2>
# <div class="categories">Filed under {{ post.categories | category_links }}</div>
# {% endfor %}
# </ul>
# ================================== COPY ABOVE THIS LINE ==================================
#
# You can alter the _layout_ setting if you wish to use an alternate layout, and obviously you
# can change the HTML above as you see fit.
#
# When you compile your jekyll site, this plugin will loop through the list of categories in your
# site, and use the layout above to generate a page for each one with a list of links to the
# individual posts.
#
# You can also (optionally) generate an atom.xml feed for each category. To do this, copy
# the category_feed.xml file to the _includes/custom directory of your own project
# (https://github.com/recurser/jekyll-plugins/blob/master/_includes/custom/category_feed.xml).
# You'll also need to copy the octopress_filters.rb file into the _plugins directory of your
# project as the category_feed.xml requires a couple of extra filters
# (https://github.com/recurser/jekyll-plugins/blob/master/_plugins/octopress_filters.rb).
#
# Included filters :
# - category_links: Outputs the list of categories as comma-separated <a> links.
# - date_to_html_string: Outputs the post.date as formatted html, with hooks for CSS styling.
#
# Available _config.yml settings :
# - category_dir: The subfolder to build category pages in (default is 'categories').
# - category_title_prefix: The string used before the category name in the page title (default is
# 'Category: ').
module Jekyll
# The CategoryIndex class creates a single category page for the specified category.
class CategoryPage < Page
# Initializes a new CategoryIndex.
#
# +template_path+ is the path to the layout template to use.
# +site+ is the Jekyll Site instance.
# +base+ is the String path to the <source>.
# +category_dir+ is the String path between <source> and the category folder.
# +category+ is the category currently being processed.
def initialize(template_path, name, site, base, category_dir, category)
@site = site
@base = base
@dir = category_dir
@name = name
self.process(name)
if File.exist?(template_path)
@perform_render = true
template_dir = File.dirname(template_path)
template = File.basename(template_path)
# Read the YAML data from the layout page.
self.read_yaml(template_dir, template)
self.data['category'] = category
# Set the title for this page.
title_prefix = site.config['category_title_prefix'] || 'Category: '
self.data['title'] = "#{title_prefix}#{category}"
# Set the meta-description for this page.
meta_description_prefix = site.config['category_meta_description_prefix'] || 'Category: '
self.data['description'] = "#{meta_description_prefix}#{category}"
else
@perform_render = false
end
end
def render?
@perform_render
end
end
# The CategoryIndex class creates a single category page for the specified category.
class CategoryIndex < CategoryPage
# Initializes a new CategoryIndex.
#
# +site+ is the Jekyll Site instance.
# +base+ is the String path to the <source>.
# +category_dir+ is the String path between <source> and the category folder.
# +category+ is the category currently being processed.
def initialize(site, base, category_dir, category)
template_path = File.join(base, '_layouts', 'category_index.html')
super(template_path, 'index.html', site, base, category_dir, category)
end
end
# The CategoryFeed class creates an Atom feed for the specified category.
class CategoryFeed < CategoryPage
# Initializes a new CategoryFeed.
#
# +site+ is the Jekyll Site instance.
# +base+ is the String path to the <source>.
# +category_dir+ is the String path between <source> and the category folder.
# +category+ is the category currently being processed.
def initialize(site, base, category_dir, category)
template_path = File.join(base, '_includes', 'custom', 'category_feed.xml')
super(template_path, 'atom.xml', site, base, category_dir, category)
# Set the correct feed URL.
self.data['feed_url'] = "#{category_dir}/#{name}" if render?
end
end
# The Site class is a built-in Jekyll class with access to global site config information.
class Site
# Creates an instance of CategoryIndex for each category page, renders it, and
# writes the output to a file.
#
# +category+ is the category currently being processed.
def write_category_index(category)
target_dir = GenerateCategories.category_dir(self.config['category_dir'], category)
index = CategoryIndex.new(self, self.source, target_dir, category)
if index.render?
index.render(self.layouts, site_payload)
index.write(self.dest)
# Record the fact that this pages has been added, otherwise Site::cleanup will remove it.
self.pages << index
end
# Create an Atom-feed for each index.
feed = CategoryFeed.new(self, self.source, target_dir, category)
if feed.render?
feed.render(self.layouts, site_payload)
feed.write(self.dest)
# Record the fact that this pages has been added, otherwise Site::cleanup will remove it.
self.pages << feed
end
end
# Loops through the list of category pages and processes each one.
def write_category_indexes
if self.layouts.key? 'category_index'
self.categories.keys.each do |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
end
# Jekyll hook - the generate method is called by jekyll, and generates all of the category pages.
class GenerateCategories < Generator
safe true
priority :low
CATEGORY_DIR = 'categories'
def generate(site)
site.write_category_indexes
end
# Processes the given dir and removes leading and trailing slashes. Falls
# back on the default if no dir is provided.
def self.category_dir(base_dir, category)
base_dir = (base_dir || CATEGORY_DIR).gsub(/^\/*(.*)\/*$/, '\1')
category = category.gsub(/_|\P{Word}/, '-').gsub(/-{2,}/, '-').downcase
File.join(base_dir, category)
end
end
# Adds some extra filters used during the category creation process.
module CategoryFilter
# Outputs a list of categories as comma-separated <a> links. This is used
# to output the category list for each post on a category page.
#
# +categories+ is the list of categories to format.
#
# Returns string
def category_links(categories)
base_dir = @context.registers[:site].config['category_dir']
categories = categories.sort!.map do |category|
category_dir = GenerateCategories.category_dir(base_dir, category)
# Make sure the category directory begins with a slash.
category_dir = "/#{category_dir}" unless category_dir =~ /^\//
"<a class='category' href='#{category_dir}/'>#{category}</a>"
end
case categories.length
when 0
""
when 1
categories[0].to_s
else
categories.join(', ')
end
end
# Outputs a single category as an <a> link.
#
# +category+ is a category string to format as an <a> link
#
# Returns string
#
def category_link(category)
base_dir = @context.registers[:site].config['category_dir']
category_dir = GenerateCategories.category_dir(base_dir, category)
"<a class='category' href='/#{category_dir}/'>#{category}</a>"
end
# Outputs the post.date as formatted html, with hooks for CSS styling.
#
# +date+ is the date object to format as HTML.
#
# Returns string
def date_to_html_string(date)
result = '<span class="month">' + date.strftime('%b').upcase + '</span> '
result += date.strftime('<span class="day">%d</span> ')
result += date.strftime('<span class="year">%Y</span> ')
result
end
end
end
Liquid::Template.register_filter(Jekyll::CategoryFilter)