Merging in calavera's pagination branch

lib/jekyll.rb

@@ -16,6 +16,7 @@ require 'redcloth'
 
 # internal requires
 require 'jekyll/core_ext'
+require 'jekyll/pager'
 require 'jekyll/site'
 require 'jekyll/convertible'
 require 'jekyll/layout'

lib/jekyll/page.rb

@@ -46,18 +46,21 @@ module Jekyll
     end
 
     # Write the generated page file to the destination directory.
-    #   +dest+ is the String path to the destination dir
+    #   +dest_prefix+ is the String path to the destination dir
+    #   +dest_suffix+ is a suffix path to the destination dir
     #
     # Returns nothing
-    def write(dest)
-      FileUtils.mkdir_p(File.join(dest, @dir))
+    def write(dest_prefix, dest_suffix = nil)
+      dest = File.join(dest_prefix, @dir)
+      dest = File.join(dest, dest_suffix) if dest_suffix
+      FileUtils.mkdir_p(dest)
 
       name = @name
       if self.ext != ""
         name = @name.split(".")[0..-2].join('.') + self.ext
       end
 
-      path = File.join(dest, @dir, name)
+      path = File.join(dest, name)
       File.open(path, 'w') do |f|
         f.write(self.output)
       end

lib/jekyll/pager.rb

@@ -0,0 +1,45 @@
+module Jekyll
+  class Pager
+    attr_reader :page, :per_page, :posts, :total_posts, :total_pages, :previous_page, :next_page
+    
+    def self.calculate_pages(all_posts, per_page)
+      num_pages = all_posts.size / per_page.to_i
+      num_pages.abs + 1 if all_posts.size % per_page.to_i != 0
+      num_pages
+    end
+    
+    def self.pagination_enabled?(config, file)
+      file == 'index.html' && !config['paginate'].nil?
+    end
+    
+    def initialize(config, page, all_posts, num_pages = nil)
+      @page = page
+      @per_page = 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 grater 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
+      @next_page = @page != @total_pages ? @page + 1 : nil
+    end
+    
+    def to_hash
+      {
+        '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

lib/jekyll/site.rb

@@ -172,11 +172,14 @@ module Jekyll
         directories.delete('_posts')
         read_posts(dir)
       end
+      
       [directories, files].each do |entries|
         entries.each do |f|
           if File.directory?(File.join(base, f))
             next if self.dest.sub(/\/$/, '') == File.join(base, f)
             transform_pages(File.join(dir, f))
+          elsif Pager.pagination_enabled?(self.config, f)
+            paginate_posts(f, dir)
           else
             first3 = File.open(File.join(self.source, dir, f)) { |fd| fd.read(3) }
 
@@ -233,5 +236,30 @@ module Jekyll
         end
       end
     end
+
+    # Paginates the blog's posts. Renders the index.html file into paginated directories, ie: page2, page3...
+    # and adds more wite-wide data
+    #
+    # {"paginator" => { "page" => <Number>,
+    #                   "per_page" => <Number>,
+    #                   "posts" => [<Post>],
+    #                   "total_posts" => <Number>,
+    #                   "total_pages" => <Number>,
+    #                   "previous_page" => <Number>,
+    #                   "next_page" => <Number> }}
+    def paginate_posts(file, dir)
+      all_posts = self.posts.sort { |a,b| b <=> a }
+      page = Page.new(self, self.source, dir, file)
+
+      pages = Pager.calculate_pages(all_posts, self.config['paginate'].to_i)
+
+      (1..pages).each do |num_page|
+        pager = Pager.new(self.config, num_page, all_posts, pages)
+
+        page.render(self.layouts, site_payload.merge({'paginator' => pager.to_hash}))
+        suffix = "page#{num_page}" if num_page > 1
+        page.write(self.dest, suffix)
+      end
+    end
   end
 end