Added tags to posts. Based off Henrik's implementation in 072d9e7.

features/post_data.feature

@@ -70,6 +70,17 @@ Feature: Post data
     Then the _site directory should exist
     And I should see "Post category: movies" in "_site/movies/2009/03/27/star-wars.html"
 
+  Scenario: Use post.tags variable
+    Given I have a _posts directory
+    And I have a _layouts directory
+    And I have the following post:
+      | title     | date      | layout | tag   | content                 |
+      | Star Wars | 5/18/2009 | simple | twist | Luke, I am your father. |
+    And I have a simple layout that contains "Post tags: {{ site.posts.first.tags }}"
+    When I run jekyll
+    Then the _site directory should exist
+    And I should see "Post tags: twist" in "_site/2009/05/18/star-wars.html"
+
   Scenario: Use post.categories variable when categories are in folders
     Given I have a movies directory
     And I have a movies/scifi directory

features/step_definitions/jekyll_steps.rb

@@ -57,7 +57,7 @@ Given /^I have the following posts?(?: (.*) "(.*)")?:$/ do |direction, folder, t
     path = File.join(before || '.', '_posts', after || '.', "#{date}-#{title}.#{post['type'] || 'textile'}")
 
     matter_hash = {}
-    %w(title layout tags category categories published author).each do |key|
+    %w(title layout tag tags category categories published author).each do |key|
       matter_hash[key] = post[key] if post[key]
     end
     matter = matter_hash.map { |k, v| "#{k}: #{v}\n" }.join.chomp

lib/jekyll/convertible.rb

@@ -22,6 +22,14 @@ module Jekyll
         self.content = self.content[($1.size + 5)..-1]
 
         self.data = YAML.load($1)
+
+        if self.data.has_key?("tag")
+          self.tags = [self.data["tag"]]
+        elsif self.data.has_key?("tags")
+          self.tags = self.data['tags']
+        else
+          self.tags = []
+        end
       end
     end
 

lib/jekyll/post.rb

@@ -18,7 +18,7 @@ module Jekyll
       name =~ MATCHER
     end
 
-    attr_accessor :site, :date, :slug, :ext, :published, :data, :content, :output
+    attr_accessor :site, :date, :slug, :ext, :published, :data, :content, :output, :tags
     attr_writer :categories
 
     def categories
@@ -208,6 +208,7 @@ module Jekyll
         "categories" => self.categories,
         "next"       => self.next,
         "previous"   => self.previous,
+        "tags"       => self.tags,
         "content"    => self.content }.deep_merge(self.data)
     end
 

test/source/_posts/2009-05-18-tag.textile

@@ -0,0 +1,6 @@
+---
+title: A Tag
+tag: code
+---
+
+Whoa.

test/source/_posts/2009-05-18-tags.textile

@@ -0,0 +1,9 @@
+---
+title: Some Tags
+tags:
+- food
+- cooking
+- pizza
+---
+
+Awesome!

test/test_post.rb

@@ -211,6 +211,18 @@ class TestPost < Test::Unit::TestCase
         assert post.categories.include?('baz')
       end
 
+      should "recognize tag in yaml" do
+        post = setup_post("2009-05-18-tag.textile")
+        assert post.tags.include?('code')
+      end
+
+      should "recognize tags in yaml" do
+        post = setup_post("2009-05-18-tags.textile")
+        assert post.tags.include?('food')
+        assert post.tags.include?('cooking')
+        assert post.tags.include?('pizza')
+      end
+
       context "rendering" do
         setup do
           clear_dest