From 8319d78c2e926c1cfb30cbc1bb8e85e5b0fa5548 Mon Sep 17 00:00:00 2001
From: Prathan Thananart <semicomma@gmail.com>
Date: Thu, 28 Apr 2011 12:00:21 +0700
Subject: [PATCH 1/3] Added a failing test case for for-else

---
 test/lib/liquid/tags/standard_tag_test.rb | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/lib/liquid/tags/standard_tag_test.rb b/test/lib/liquid/tags/standard_tag_test.rb
index 4e14949..46c1a7f 100644
--- a/test/lib/liquid/tags/standard_tag_test.rb
+++ b/test/lib/liquid/tags/standard_tag_test.rb
@@ -102,6 +102,12 @@ HERE
                            assigns)
   end
 
+  def test_for_else
+    assert_template_result('+++', '{%for item in array%}+{%else%}-{%endfor%}', 'array'=>[1,2,3])
+    assert_template_result('-',   '{%for item in array%}+{%else%}-{%endfor%}', 'array'=>[])
+    assert_template_result('-',   '{%for item in array%}+{%else%}-{%endfor%}', 'array'=>nil)
+  end
+
   def test_limiting
     assigns = {'array' => [1,2,3,4,5,6,7,8,9,0]}
     assert_template_result('12', '{%for i in array limit:2 %}{{ i }}{%endfor%}', assigns)

From caf59940d34c98d66ca8ae22142a9adca7e7f000 Mon Sep 17 00:00:00 2001
From: Prathan Thananart <semicomma@gmail.com>
Date: Thu, 28 Apr 2011 13:07:41 +0700
Subject: [PATCH 2/3] Added code to make for-else work

---
 lib/liquid/tags/for.rb | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/lib/liquid/tags/for.rb b/lib/liquid/tags/for.rb
index b17a332..810eb0f 100644
--- a/lib/liquid/tags/for.rb
+++ b/lib/liquid/tags/for.rb
@@ -58,8 +58,14 @@ module Liquid
         raise SyntaxError.new("Syntax Error in 'for loop' - Valid syntax: for [item] in [collection]")
       end
 
+      @nodelist = @for_block = []
       super
     end
+
+    def unknown_tag(tag, markup, tokens)
+      return super unless tag == 'else'
+      @nodelist = @else_block = []
+    end
   
     def render(context)        
       context.registers[:for] ||= Hash.new(0)
@@ -67,7 +73,7 @@ module Liquid
       collection = context[@collection_name]
       collection = collection.to_a if collection.is_a?(Range)
     
-      return '' unless collection.respond_to?(:each) 
+      return render_else(context) unless collection.respond_to?(:each) 
                                                  
       from = if @attributes['offset'] == 'continue'
         context.registers[:for][@name].to_i
@@ -81,7 +87,7 @@ module Liquid
                        
       segment = slice_collection_using_each(collection, from, to)      
       
-      return '' if segment.empty?
+      return render_else(context) if segment.empty?
       
       segment.reverse! if @reversed
 
@@ -105,7 +111,7 @@ module Liquid
             'first'   => (index == 0),
             'last'    => (index == length - 1) }
 
-          result << render_all(@nodelist, context)
+          result << render_all(@for_block, context)
         end
       end
       result     
@@ -130,7 +136,14 @@ module Liquid
 
       segments
     end
+
+    private
+
+      def render_else(context)
+        return @else_block ? [render_all(@else_block, context)] : ''
+      end
+
   end
 
   Template.register_tag('for', For)
-end
\ No newline at end of file
+end

From d19213177a552a5980b9db330e0d027e42bbe575 Mon Sep 17 00:00:00 2001
From: Prathan Thananart <semicomma@gmail.com>
Date: Thu, 28 Apr 2011 13:11:13 +0700
Subject: [PATCH 3/3] Added documentation for for-else

---
 lib/liquid/tags/for.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/liquid/tags/for.rb b/lib/liquid/tags/for.rb
index 810eb0f..9461a8b 100644
--- a/lib/liquid/tags/for.rb
+++ b/lib/liquid/tags/for.rb
@@ -13,6 +13,8 @@ module Liquid
   #      <div {% if forloop.first %}class="first"{% endif %}>
   #        Item {{ forloop.index }}: {{ item.name }}
   #      </div>
+  #    {% else %}
+  #      There is nothing in the collection.
   #    {% endfor %}
   #
   # You can also define a limit and offset much like SQL.  Remember