From 75f4835d3e5d74fb7d4c5dc7af154e9c36f0522e Mon Sep 17 00:00:00 2001
From: Karl Brightman <karl@karlbright.org>
Date: Fri, 16 Sep 2011 11:35:40 +0800
Subject: [PATCH 1/3] Integrated next and previous methods for content in
 content types

---
 app/models/content_instance.rb         |  8 +++++++
 lib/locomotive/liquid/drops/content.rb |  8 +++++++
 spec/models/content_instance_spec.rb   | 29 ++++++++++++++++++++++++++
 3 files changed, 45 insertions(+)

diff --git a/app/models/content_instance.rb b/app/models/content_instance.rb
index 0322ff86..7f4a289e 100644
--- a/app/models/content_instance.rb
+++ b/app/models/content_instance.rb
@@ -50,6 +50,14 @@ class ContentInstance
   def visible?
     self._visible || self._visible.nil?
   end
+  
+  def next
+    content_type.contents.where(_position_in_list: _position_in_list + 1).first()
+  end
+  
+  def previous
+    content_type.contents.where(_position_in_list: _position_in_list - 1).first()
+  end
 
   def errors_to_hash
     Hash.new.replace(self.errors)
diff --git a/lib/locomotive/liquid/drops/content.rb b/lib/locomotive/liquid/drops/content.rb
index 1aefc759..118d4380 100644
--- a/lib/locomotive/liquid/drops/content.rb
+++ b/lib/locomotive/liquid/drops/content.rb
@@ -8,6 +8,14 @@ module Locomotive
         def _id
           self._source._id.to_s
         end
+        
+        def next
+          self._source.next.to_liquid
+        end
+        
+        def previous
+          self._source.previous.to_liquid
+        end
 
         def before_method(meth)
           return '' if self._source.nil?
diff --git a/spec/models/content_instance_spec.rb b/spec/models/content_instance_spec.rb
index f34e2957..ef49fcd5 100644
--- a/spec/models/content_instance_spec.rb
+++ b/spec/models/content_instance_spec.rb
@@ -41,6 +41,35 @@ describe ContentInstance do
     end
 
   end
+  
+  describe "#navigation" do
+    before(:each) do
+      %w(first second third).each_with_index do |item,index|
+        content = build_content({:title => item.to_s})
+        content._position_in_list = index
+        instance_variable_set "@#{item}", content
+      end
+    end
+    
+    it 'should find previous item when available' do
+      puts @second.previous
+      @second.previous.custom_field_1.should == "first"
+      @second.previous._position_in_list.should == 0
+    end
+    
+    it 'should find next item when available' do
+      @second.next.custom_field_1.should == "third"
+      @second.next._position_in_list.should == 2
+    end
+    
+    it 'should return nil when fetching previous item on first in list' do
+      @first.previous.should == nil
+    end
+    
+    it 'should return nil when fetching next item on last in list' do
+      @third.next.should == nil
+    end
+  end
 
   describe '#permalink' do
 

From 769b0569dbceddafa0028d84f2a6a55b2761b2b9 Mon Sep 17 00:00:00 2001
From: Karl Brightman <karl@karlbright.org>
Date: Fri, 16 Sep 2011 11:37:48 +0800
Subject: [PATCH 2/3] Added examples

---
 lib/locomotive/liquid/drops/content.rb | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/lib/locomotive/liquid/drops/content.rb b/lib/locomotive/liquid/drops/content.rb
index 118d4380..2e3fcb37 100644
--- a/lib/locomotive/liquid/drops/content.rb
+++ b/lib/locomotive/liquid/drops/content.rb
@@ -9,10 +9,28 @@ module Locomotive
           self._source._id.to_s
         end
         
+        # Returns the next content for the parent content type.
+        # If no content is found, nil is returned.
+        #
+        # Usage:
+        #
+        # {% if article.next %}
+        # <a href="/articles/{{ article.next._permalink }}">Read next article</a>
+        # {% endif %}
+        #
         def next
           self._source.next.to_liquid
         end
         
+        # Returns the previous content for the parent content type.
+        # If no content is found, nil is returned.
+        #
+        # Usage:
+        #
+        # {% if article.previous %}
+        # <a href="/articles/{{ article.previous._permalink }}">Read previous article</a>
+        # {% endif %}
+        #
         def previous
           self._source.previous.to_liquid
         end

From 93667018c1b36126bf238b6fd4fde31550203e38 Mon Sep 17 00:00:00 2001
From: Karl Brightman <karl@karlbright.org>
Date: Fri, 16 Sep 2011 11:55:30 +0800
Subject: [PATCH 3/3] Updated with hashrocket

---
 app/models/content_instance.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/models/content_instance.rb b/app/models/content_instance.rb
index 7f4a289e..527c76ba 100644
--- a/app/models/content_instance.rb
+++ b/app/models/content_instance.rb
@@ -52,11 +52,11 @@ class ContentInstance
   end
   
   def next
-    content_type.contents.where(_position_in_list: _position_in_list + 1).first()
+    content_type.contents.where(:_position_in_list => _position_in_list + 1).first()
   end
   
   def previous
-    content_type.contents.where(_position_in_list: _position_in_list - 1).first()
+    content_type.contents.where(:_position_in_list => _position_in_list - 1).first()
   end
 
   def errors_to_hash