Move things around.

README.md

@@ -18,7 +18,7 @@ Or install it yourself as:
 
 ## Usage
 
-Once the gem is installed in your
+Once the gem is installed on your system, Jekyll will auto-require it. Just set the following configuration
 
 ## Contributing
 

jekyll-paginate.gemspec

@@ -1,7 +1,7 @@
 # coding: utf-8
 lib = File.expand_path('../lib', __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
-require 'jekyll/paginate/version'
+require 'jekyll-paginate/version'
 
 Gem::Specification.new do |spec|
   spec.name          = "jekyll-paginate"

lib/jekyll-paginate.rb

@@ -0,0 +1,8 @@
+require "jekyll-paginate/version"
+require "jekyll-paginate/pager"
+require "jekyll-paginate/pagination"
+
+module Jekyll
+  module Paginate
+  end
+end

lib/jekyll-paginate/pager.rb

@@ -0,0 +1,137 @@
+module Jekyll
+  module Paginate
+    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 pagination is enabled the site.
+      #
+      # site - the Jekyll::Site object
+      #
+      # Returns true if pagination is enabled, false otherwise.
+      def self.pagination_enabled?(site)
+       !site.config['paginate'].nil? &&
+         site.pages.size > 0
+      end
+
+      # Static: Determine if a page is a possible candidate to be a template page.
+      #         Page's name must be `index.html` and exist in any of the directories
+      #         between the site source and `paginate_path`.
+      #
+      # config - the site configuration hash
+      # page   - the Jekyll::Page about which we're inquiring
+      #
+      # Returns true if the
+      def self.pagination_candidate?(config, page)
+        page_dir = File.dirname(File.expand_path(remove_leading_slash(page.path), config['source']))
+        paginate_path = remove_leading_slash(config['paginate_path'])
+        paginate_path = File.expand_path(paginate_path, config['source'])
+        page.name == 'index.html' &&
+          in_hierarchy(config['source'], page_dir, File.dirname(paginate_path))
+      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
+      #
+      # Returns the pagination path as a string
+      def self.paginate_path(site, num_page)
+        return nil if num_page.nil?
+        return Generators::Pagination.first_page_url(site) 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.
+      #
+      # site     - the Jekyll::Site object
+      # 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)
+        @page = page
+        @per_page = site.config['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)
+        @next_page = @page != @total_pages ? @page + 1 : nil
+        @next_page_path = Pager.paginate_path(site, @next_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
+end

lib/jekyll-paginate/pagination.rb

@@ -0,0 +1,85 @@
+module Jekyll
+  module Generators
+    class Pagination < Generator
+      # This generator is safe from arbitrary code execution.
+      safe true
+
+      # This generator should be passive with regard to its execution
+      priority :lowest
+
+      # Generate paginated pages if necessary.
+      #
+      # site - The Site.
+      #
+      # Returns nothing.
+      def generate(site)
+        if Pager.pagination_enabled?(site)
+          if template = template_page(site)
+            paginate(site, template)
+          else
+            Jekyll.logger.warn "Pagination:", "Pagination is enabled, but I couldn't find " +
+            "an index.html page to use as the pagination template. Skipping pagination."
+          end
+        end
+      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)
+        all_posts = site.site_payload['site']['posts']
+        pages = Pager.calculate_pages(all_posts, site.config['paginate'].to_i)
+        (1..pages).each do |num_page|
+          pager = Pager.new(site, num_page, all_posts, pages)
+          if num_page > 1
+            newpage = Page.new(site, site.source, page.dir, page.name)
+            newpage.pager = pager
+            newpage.dir = Pager.paginate_path(site, num_page)
+            site.pages << newpage
+          else
+            page.pager = pager
+          end
+        end
+      end
+
+      # Static: Fetch the URL of the template page. Used to determine the
+      #         path to the first pager in the series.
+      #
+      # site - the Jekyll::Site object
+      #
+      # Returns the url of the template page
+      def self.first_page_url(site)
+        if page = Pagination.new.template_page(site)
+          page.url
+        else
+          nil
+        end
+      end
+
+      # Public: Find the Jekyll::Page which will act as the pager template
+      #
+      # site - the Jekyll::Site object
+      #
+      # Returns the Jekyll::Page which will act as the pager template
+      def template_page(site)
+        site.pages.dup.select do |page|
+          Pager.pagination_candidate?(site.config, page)
+        end.sort do |one, two|
+          two.path.size <=> one.path.size
+        end.first
+      end
+
+    end
+  end
+end