module Jekyll 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) site.pages.dup.each do |page| paginate(site, page) if Pager.pagination_enabled?(site.config, page) 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" => , # "per_page" => , # "posts" => [], # "total_posts" => , # "total_pages" => , # "previous_page" => , # "next_page" => }} def paginate(site, page) all_posts = site.site_payload['site']['posts'] pages = Pager.calculate_pages(all_posts, site.config['paginate'].to_i) page_dir = page.destination('').sub(/\/[^\/]+$/, '') page_dir_config = site.config['pagination_dir'] dir = ((page_dir_config || page_dir) + '/').sub(/^\/+/, '') (1..pages).each do |num_page| pager = Pager.new(site.config, num_page, all_posts, pages, page_dir+'/', '/'+dir) if num_page > 1 newpage = Page.new(site, site.source, page_dir, page.name) newpage.pager = pager newpage.dir = File.join(page.dir, "#{dir}page/#{num_page}") site.pages << newpage else page.pager = pager end end end end class Pager attr_reader :page, :per_page, :posts, :total_posts, :total_pages, :previous_page, :next_page # 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 for a given file. # # config - The configuration Hash. # file - The String filename of the file. # # Returns true if pagination is enabled, false otherwise. def self.pagination_enabled?(config, file) file.name == 'index.html' && !config['paginate'].nil? && file.content =~ /paginator\./ 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(config, page, all_posts, num_pages = nil, index_dir, pagination_dir) @page = page @per_page = config['paginate'].to_i @page_dir = pagination_dir + 'page/' @total_pages = num_pages || Pager.calculate_pages(all_posts, @per_page) @previous_page = nil 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_dir + (@page - 1).to_s + '/' : nil @previous_page = index_dir if @page - 1 == 1 @next_page = @page != @total_pages ? @page_dir + (@page + 1).to_s + '/' : nil 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, 'next_page' => next_page } end end end