Merge pull request #1057 from mojombo/refactor-related-posts

Move the building of related posts into their own class

lib/jekyll.rb

@@ -40,6 +40,7 @@ require 'jekyll/draft'
 require 'jekyll/filters'
 require 'jekyll/static_file'
 require 'jekyll/errors'
+require 'jekyll/related_posts'
 
 # extensions
 require 'jekyll/plugin'

lib/jekyll/post.rb

@@ -244,29 +244,7 @@ module Jekyll
     #
     # Returns an Array of related Posts.
     def related_posts(posts)
-      return [] unless posts.size > 1
+      Jekyll::RelatedPosts.new(self).build
-
-      if self.site.lsi
-        build_index
-
-        related = self.class.lsi.find_related(self.content, 11)
-        related - [self]
-      else
-        (posts - [self])[0..9]
-      end
-    end
-
-    def build_index
-      self.class.lsi ||= begin
-        puts "Starting the classifier..."
-        lsi = Classifier::LSI.new(:auto_rebuild => false)
-        $stdout.print("  Populating LSI... "); $stdout.flush
-        self.site.posts.each { |x| $stdout.print("."); $stdout.flush; lsi.add_item(x) }
-        $stdout.print("\n  Rebuilding LSI index... ")
-        lsi.build_index
-        puts ""
-        lsi
-      end
     end
 
     # Add any necessary layouts to this post.

lib/jekyll/related_posts.rb

@@ -0,0 +1,58 @@
+module Jekyll
+  class RelatedPosts
+
+    class << self
+      attr_accessor :lsi
+    end
+
+    attr_reader :post, :site
+
+    def initialize(post)
+      @post = post
+      @site = post.site
+      require 'classifier' if site.lsi
+    end
+
+    def build
+      return [] unless self.site.posts.size > 1
+
+      if self.site.lsi
+        build_index
+        lsi_related_posts
+      else
+        most_recent_posts
+      end
+    end
+
+
+    def build_index
+      self.class.lsi ||= begin
+        lsi = Classifier::LSI.new(:auto_rebuild => false)
+        display("Populating LSI...")
+
+        self.site.posts.each do |x|
+          lsi.add_item(x)
+        end
+
+        display("Rebuilding index...")
+        lsi.build_index
+        display("")
+        lsi
+      end
+    end
+
+    def lsi_related_posts
+      self.class.lsi.find_related(post.content, 11) - [self.post]
+    end
+
+    def most_recent_posts
+      (self.site.posts - [self.post])[0..9]
+    end
+
+    def display(output)
+      $stdout.print("\n")
+      $stdout.print(Jekyll::Stevenson.formatted_topic(output))
+      $stdout.flush
+    end
+  end
+end

lib/jekyll/site.rb

@@ -71,8 +71,6 @@ module Jekyll
     #
     # Returns nothing.
     def setup
-      require 'classifier' if self.lsi
-
       # Check that the destination dir isn't the source dir or a directory
       # parent to the source dir.
       if self.source =~ /^#{self.dest}/

test/test_related_posts.rb

@@ -0,0 +1,41 @@
+require 'helper'
+
+class TestRelatedPosts < Test::Unit::TestCase
+  context "building related posts without lsi" do
+    setup do
+      stub(Jekyll).configuration do
+        Jekyll::Configuration::DEFAULTS.merge({'source' => source_dir,
+                                               'destination' => dest_dir})
+      end
+      @site = Site.new(Jekyll.configuration)
+    end
+
+    should "use the most recent posts for related posts" do
+      @site.reset
+      @site.read
+      assert_equal @site.posts[0..9], Jekyll::RelatedPosts.new(@site.posts.last).build
+    end
+  end
+
+  context "building related posts with lsi" do
+    setup do
+      stub(Jekyll).configuration do
+        Jekyll::Configuration::DEFAULTS.merge({'source' => source_dir,
+                                               'destination' => dest_dir,
+                                               'lsi' => true})
+      end
+      @site = Site.new(Jekyll.configuration)
+    end
+
+    should "use lsi for the related posts" do
+      @site.reset
+      @site.read
+      require 'classifier'
+      any_instance_of(::Classifier::LSI) do |c|
+        stub(c).find_related { @site.posts[-1..-9] }
+        stub(c).build_index
+      end
+      assert_equal @site.posts[-1..-9], Jekyll::RelatedPosts.new(@site.posts.last).build
+    end
+  end
+end