Merging in calavera's pagination branch

bin/jekyll

@@ -52,6 +52,16 @@ opts = OptionParser.new do |opts|
     options['permalink'] = style unless style.nil?
   end
   
+  opts.on("--paginate [POSTS_PER_PAGE]", "Paginate a blog's posts") do |per_page|
+    begin
+      options['paginate'] = per_page.to_i
+      raise ArgumentError if options['paginate'] == 0
+    rescue
+      puts 'you must specify a number of posts by page bigger than 0'
+      exit 0
+    end
+  end
+
   opts.on("--version", "Display current version") do
     puts "Jekyll " + Jekyll.version
     exit 0

features/pagination.feature

@@ -0,0 +1,22 @@
+Feature: Site pagination
+  In order to paginate my blog
+  As a blog's user
+  I want divide the posts in several pages
+  
+  Scenario: Create pages
+    Given I have a configuration file with "paginate" set to "1"
+    And I have a _layouts directory
+    And I have an "index.html" file that contains "Basic Site"
+    And I have a _posts directory
+    And I have the following post:
+      | title    | date      | layout  | content                               |
+      | Wargames | 3/27/2009 | default | The only winning move is not to play. |
+      | Wargames2 | 4/27/2009 | default | The only winning move is not to play2. |
+    When I run jekyll
+    Then the _site/page2 directory should exist
+    And the _site/page2/index.html file should exist
+  
+  
+  
+
+  

features/site_data.feature

@@ -10,7 +10,7 @@ Feature: Site data
     And I should see "Contact: email@me.com" in "_site/contact.html"
 
   Scenario: Use site.time variable
-    Given I have an "index.html" page that contains "Generated on: {{ site.time }}"
+    Given I have an "index.html" page that contains "{{ site.time }}"
     When I run jekyll
     Then the _site directory should exist
     And I should see today's time in "_site/index.html"

features/step_definitions/jekyll_steps.rb

@@ -115,6 +115,10 @@ Then /^the (.*) directory should exist$/ do |dir|
   assert File.directory?(dir)
 end
 
+Then /^the (.*) file should exist$/ do |file|
+  assert File.file?(file)
+end
+
 Then /^I should see "(.*)" in "(.*)"$/ do |text, file|
   assert_match Regexp.new(text), File.open(file).readlines.join
 end
@@ -130,4 +134,3 @@ end
 Then /^I should see today's date in "(.*)"$/ do |file|
   assert_match Regexp.new(Date.today.to_s), File.open(file).readlines.join
 end
-

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)
+    def write(dest_prefix, dest_suffix = nil)
-      FileUtils.mkdir_p(File.join(dest, @dir))
+      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

test/test_pager.rb

@@ -0,0 +1,47 @@
+require File.dirname(__FILE__) + '/helper'
+
+class TestPager < Test::Unit::TestCase
+  
+  def setup
+    stub(Jekyll).configuration do
+      Jekyll::DEFAULTS.merge({'source' => source_dir, 'destination' => dest_dir,
+        'paginate' => 2})
+    end
+
+    @config = Jekyll.configuration
+    @site = Site.new(@config)
+    @posts = @site.read_posts('')
+  end
+  
+  def teardown
+    @config = Jekyll.configuration('paginate' => nil)
+  end
+  
+  def test_calculate_pages
+    assert_equal(2, Pager.calculate_pages(@posts, @config['paginate']))
+  end
+
+  def test_create_first_pager
+    pager = Pager.new(@config, 1, @posts)
+    assert_equal(@config['paginate'].to_i, pager.posts.size)
+    assert_equal(2, pager.total_pages)
+    assert_nil(pager.previous_page)
+    assert_equal(2, pager.next_page)
+  end
+  
+  def test_create_second_pager
+    pager = Pager.new(@config, 2, @posts)
+    assert_equal(@posts.size - @config['paginate'].to_i, pager.posts.size)
+    assert_equal(2, pager.total_pages)
+    assert_equal(1, pager.previous_page)
+    assert_nil(pager.next_page)
+  end
+  
+  def test_create_third_pager
+    assert_raise(RuntimeError) { Pager.new(@config, 3, @posts) }
+  end
+  
+  def test_pagination_enabled_with_command_option
+    assert_equal(true, Pager.pagination_enabled?(@config, 'index.html'))
+  end
+end