Support a new `relative_include` tag

lib/jekyll/tags/include.rb

@@ -18,9 +18,15 @@ module Jekyll
       VALID_SYNTAX = /([\w-]+)\s*=\s*(?:"([^"\\]*(?:\\.[^"\\]*)*)"|'([^'\\]*(?:\\.[^'\\]*)*)'|([\w\.-]+))/
       VARIABLE_SYNTAX = /(?<variable>[^{]*\{\{\s*(?<name>[\w\-\.]+)\s*(\|.*)?\}\}[^\s}]*)(?<params>.*)/
 
-      INCLUDES_DIR = '_includes'
-
       def initialize(tag_name, markup, tokens)
+        @tag_name = tag_name
+        case tag_name
+        when 'include'
+          @includes_dir = '_includes'
+        when 'relative_include'
+          @includes_dir = ''
+        end
+
         super
         matched = markup.strip.match(VARIABLE_SYNTAX)
         if matched
@@ -97,8 +103,12 @@ eos
       end
 
       def render(context)
-        dir = File.join(File.realpath(context.registers[:site].source), INCLUDES_DIR)
-
+        case @tag_name
+        when 'include'
+          dir = File.join(File.realpath(context.registers[:site].source), @includes_dir)
+        when 'relative_include'
+          dir = File.join(File.realpath(context.registers[:site].source), File.dirname(context.registers[:page]["path"]))
+        end
         file = render_variable(context) || @file
         validate_file_name(file)
 
@@ -113,7 +123,7 @@ eos
             partial.render!(context)
           end
         rescue => e
-          raise IncludeTagError.new e.message, File.join(INCLUDES_DIR, @file)
+          raise IncludeTagError.new e.message, File.join(@includes_dir, @file)
         end
       end
 
@@ -126,7 +136,7 @@ eos
       end
 
       def path_relative_to_source(dir, path)
-        File.join(INCLUDES_DIR, path.sub(Regexp.new("^#{dir}"), ""))
+        File.join(@includes_dir, path.sub(Regexp.new("^#{dir}"), ""))
       end
 
       def realpath_prefixed_with?(path, dir)
@@ -138,7 +148,11 @@ eos
         File.read(file, file_read_opts(context))
       end
     end
+
+    class RelativeIncludeTag < IncludeTag
+    end
   end
 end
 
 Liquid::Template.register_tag('include', Jekyll::Tags::IncludeTag)
+Liquid::Template.register_tag('relative_include', Jekyll::Tags::RelativeIncludeTag)

test/source/_posts/2014-09-02-relative-includes.markdown

@@ -0,0 +1,25 @@
+---
+title: Post
+layout: post
+include1: rel_include.html
+include2: relative_includes/rel_include
+include3: rel_INCLUDE
+include4: params
+include5: clude
+---
+
+Liquid tests
+- 1 {% relative_include relative_includes/{{ page.include1 }} %}
+- 2 {% relative_include {{ page.include2 | append: '.html' }} %}
+- 3 {% relative_include relative_includes/{{ page.include3 | downcase | append: '.html' }} %}
+
+Whitespace tests
+- 4 {% relative_include relative_includes/{{page.include1}} %}
+- 5 {% relative_include relative_includes/{{   page.include1}} %}
+- 6 {% relative_include relative_includes/{{  page.include3   | downcase |   append:  '.html'}} %}
+
+Parameters test
+- 7 {% relative_include relative_includes/{{ page.include4 | append: '.html' }} var1='foo' var2='bar' %}
+
+Partial variable test
+- 8 {% relative_include relative_includes/rel_in{{ page.include5 }}.html %}

test/source/_posts/relative_includes/params.html

@@ -0,0 +1,7 @@
+<span id='include-param'>{{include.param}}</span>
+
+<ul id='param-list'>
+  {% for param in include %}
+    <li>{{param[0]}} = {{param[1]}}</li>
+  {% endfor %}
+</ul>

test/source/_posts/relative_includes/rel_include.html

@@ -0,0 +1 @@
+relative_included

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 42, @site.posts.size
+      assert_equal 43, @site.posts.size
     end
 
     should "insert site.posts into the index" do

test/test_site.rb

@@ -48,7 +48,7 @@ class TestSite < Test::Unit::TestCase
         Jekyll::Configuration::DEFAULTS.merge({'source' => source_dir, 'destination' => dest_dir})
       end
       @site = Site.new(Jekyll.configuration)
-      @num_invalid_posts = 2
+      @num_invalid_posts = 4
     end
 
     should "have an empty tag hash by default" do

test/test_tags.rb

@@ -509,5 +509,40 @@ CONTENT
         assert_match %r{8 included}, @content
       end
     end
+
+    context "relative include tag with variable and liquid filters" do
+      setup do
+        stub(Jekyll).configuration do
+          site_configuration({'pygments' => true})
+        end
+
+        site = Site.new(Jekyll.configuration)
+        post = Post.new(site, source_dir, '', "2014-09-02-relative-includes.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 relative_include}, @content
+        assert_match %r{2 relative_include}, @content
+        assert_match %r{3 relative_include}, @content
+      end
+
+      should "include file as variable and liquid filters with arbitrary whitespace" do
+        assert_match %r{4 relative_include}, @content
+        assert_match %r{5 relative_include}, @content
+        assert_match %r{6 relative_include}, @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
+
+      should "include file as partial variable" do
+        assert_match %r{8 relative_include}, @content
+      end
+    end
   end
 end