fix post presenter / arrow ordering

app/controllers/posts_controller.rb

@@ -33,7 +33,7 @@ class PostsController < ApplicationController
       respond_to do |format|
         format.xml{ render :xml => @post.to_diaspora_xml }
         format.mobile{render 'posts/show.mobile.haml'}
-        format.json{ render :json => PostPresenter.new(@post).to_json }
+        format.json{ render :json => PostPresenter.new(@post, current_user).to_json }
         format.any{render 'posts/show.html.haml', :layout => 'layouts/post'}
       end
 

app/models/post.rb

@@ -69,11 +69,11 @@ class Post < ActiveRecord::Base
   }
 
   def self.next(post)
-    where("posts.id > ?", post.id)
+    where("posts.created_at > ?", post.created_at)
   end
 
   def self.previous(post)
-    where("posts.id < ?", post.id)
+    where("posts.created_at < ?", post.created_at)
   end
 
   def post_type

app/presenters/post_presenter.rb

@@ -41,11 +41,10 @@ class PostPresenter
   protected
 
   def post_base
-    scope = if current_user
-      Post.owned_or_visible_by_user(current_user)
+    if current_user
+      current_user.posts_from(self.post.author)
     else
-      Post.all_public
+      self.post.author.posts.all_public
     end
-    scope.where(:author_id => post.author_id)
   end
 end

app/views/posts/show.html.haml

@@ -39,8 +39,8 @@
       %i.icon-comment.icon-white
 
 
-= link_to image_tag('arrow-left.png'), '#', :class => 'nav-arrow left', :id => 'back'
-= link_to image_tag('arrow-right.png'), '#', :class => 'nav-arrow right', :id => 'forward'
+= link_to image_tag('arrow-left.png'), '#', :class => 'nav-arrow left', :id => 'forward'
+= link_to image_tag('arrow-right.png'), '#', :class => 'nav-arrow right', :id => 'back'
 
 #comment.modal.fade
   .modal-header