simplifies parent/child preview code; fixes #1489

app/logical/post_sets/post_relationship.rb

@@ -0,0 +1,24 @@
+module PostSets
+  class PostRelationship < PostSets::Post
+    attr_reader :parent, :children
+
+    def initialize(parent_id, options = {})
+      @parent = ::Post.where("id = ?", parent_id)
+      @children = ::Post.where("parent_id = ?", parent_id).order("id ASC")
+      if options[:include_deleted]
+        super("parent:#{parent_id} status:any")
+      else
+        @children = @children.where("is_deleted = ?", false)
+        super("parent:#{parent_id}")
+      end
+    end
+
+    def posts
+      @parent + @children
+    end
+
+    def presenter
+      ::PostSetPresenters::Post.new(self)
+    end
+  end
+end