variables in include tag with filters

features/include_tag.feature

@@ -55,3 +55,14 @@ Feature: Include tags
     When I run jekyll
     Then the _site directory should exist
     And I should see "one two" in "_site/index.html"
+
+  Scenario: Include a file with variables and filters
+    Given I have an _includes directory
+    And I have an "_includes/one.html" file that contains "one included"
+    And I have a configuration file with:
+    | key          | value |
+    | include_file | one   |
+    And I have an "index.html" page that contains "{% include {{ site.include_file | append: '.html' }} %}"
+    When I run jekyll
+    Then the _site directory should exist
+    And I should see "one included" in "_site/index.html"

lib/jekyll/tags/include.rb

@@ -14,12 +14,19 @@ module Jekyll
       SYNTAX_EXAMPLE = "{% include file.ext param='value' param2='value' %}"
 
       VALID_SYNTAX = /([\w-]+)\s*=\s*(?:"([^"\\]*(?:\\.[^"\\]*)*)"|'([^'\\]*(?:\\.[^'\\]*)*)'|([\w\.-]+))/
+      VARIABLE_SYNTAX = /(?<variable>\{\{\s*(?<name>[\w\-\.]+)\s*(\|.*)?\}\})(?<params>.*)/
 
       INCLUDES_DIR = '_includes'
 
       def initialize(tag_name, markup, tokens)
         super
-        @file, @params = markup.strip.split(' ', 2);
+        matched = markup.strip.match(VARIABLE_SYNTAX)
+        if matched
+          @file = matched['variable'].strip
+          @params = matched['params'].strip
+        else
+          @file, @params = markup.strip.split(' ', 2);
+        end
         validate_params if @params
       end
 
@@ -48,7 +55,7 @@ module Jekyll
             raise ArgumentError.new <<-eos
 Invalid syntax for include tag. File contains invalid characters or sequences:
 
-	#{@file}
+	#{file}
 
 Valid syntax:
 
@@ -79,10 +86,11 @@ eos
         context.registers[:site].file_read_opts
       end
 
-      def retrieve_variable(context)
-        if /\{\{([\w\-\.]+)\}\}/ =~ @file
-          raise ArgumentError.new("No variable #{$1} was found in include tag") if context[$1].nil?
-          context[$1]
+      # Render the variable if required
+      def render_variable(context)
+        if @file.match(VARIABLE_SYNTAX)
+          partial = Liquid::Template.parse(@file)
+          partial.render!(context)
         end
       end
 
@@ -90,7 +98,7 @@ eos
         dir = File.join(context.registers[:site].source, INCLUDES_DIR)
         validate_dir(dir, context.registers[:site].safe)
 
-        file = retrieve_variable(context) || @file
+        file = render_variable(context) || @file
         validate_file_name(file)
 
         path = File.join(dir, file)
@@ -116,9 +124,9 @@ eos
 
       def validate_file(file, safe)
         if !File.exists?(file)
-          raise IOError.new "Included file '#{@file}' not found in '#{INCLUDES_DIR}' directory"
+          raise IOError.new "Included file '#{file}' not found in '#{INCLUDES_DIR}' directory"
         elsif File.symlink?(file) && safe
-          raise IOError.new "The included file '#{INCLUDES_DIR}/#{@file}' should not be a symlink"
+          raise IOError.new "The included file '#{INCLUDES_DIR}/#{file}' should not be a symlink"
         end
       end
 

test/source/_includes/include.html

@@ -0,0 +1 @@
+included

test/source/_posts/2013-12-17-include-variable-filters.markdown

@@ -0,0 +1,22 @@
+---
+title: Post
+layout: post
+include1: include.html
+include2: include
+include3: INCLUDE
+include4: params
+---
+
+Liquid tests
+- 1 {% include {{ page.include1 }} %}
+- 2 {% include {{ page.include2 | append: '.html' }} %}
+- 3 {% include {{ page.include3 | downcase | append: '.html' }} %}
+- 4 {% include {{ page.include2 | append: '.html' }} %} 
+
+Whitespace tests
+- 5 {% include {{page.include1}} %}
+- 6 {% include {{   page.include1}} %}
+- 7 {% include {{  page.include3   | downcase |   append:  '.html'}} %}
+
+Parameters test
+- 8 {% include {{ page.include4 | append: '.html' }} var1='foo' var2='bar' %}

test/test_generated_site.rb

@@ -14,7 +14,7 @@ class TestGeneratedSite < Test::Unit::TestCase
     end
 
     should "ensure post count is as expected" do
-      assert_equal 36, @site.posts.size
+      assert_equal 37, @site.posts.size
     end
 
     should "insert site.posts into the index" do

test/test_tags.rb

@@ -471,5 +471,36 @@ CONTENT
       end
     end
 
+    context "include tag with variable and liquid filters" do
+      setup do
+        stub(Jekyll).configuration do
+          Jekyll::Configuration::DEFAULTS.deep_merge({'pygments' => true}).deep_merge({'source' => source_dir, 'destination' => dest_dir})
+        end
+
+        site = Site.new(Jekyll.configuration)
+        post = Post.new(site, source_dir, '', "2013-12-17-include-variable-filters.markdown")
+        layouts = { "default" => Layout.new(site, source_dir('_layouts'), "simple.html")}
+        post.render(layouts, {"site" => {"posts" => []}})
+        @content = post.content
+      end
+
+      should "include file as variable with liquid filters" do
+        assert_match %r{1 included}, @content
+        assert_match %r{2 included}, @content
+        assert_match %r{3 included}, @content
+        assert_match %r{4 included}, @content
+      end
+
+      should "include file as variable and liquid filters with arbitrary whitespace" do
+        assert_match %r{5 included}, @content
+        assert_match %r{6 included}, @content
+        assert_match %r{7 included}, @content
+      end
+
+      should "include file as variable and filters with additional parameters" do
+        assert_match '<li>var1 = foo</li>', @content
+        assert_match '<li>var2 = bar</li>', @content
+      end
+    end
   end
 end