sql conditions to class level

ancestry.gemspec

@@ -31,6 +31,7 @@ EOF
     'lib/ancestry/exceptions.rb',
     'lib/ancestry/class_methods.rb',
     'lib/ancestry/instance_methods.rb',
+    'lib/ancestry/materialized_path.rb',
     'MIT-LICENSE',
     'README.rdoc'
   ]

lib/ancestry.rb

@@ -2,7 +2,8 @@
 require_relative 'ancestry/instance_methods'
 require_relative 'ancestry/exceptions'
 require_relative 'ancestry/has_ancestry'
+require_relative 'ancestry/materialized_path'
 
 module Ancestry
   ANCESTRY_PATTERN = /\A[0-9]+(\/[0-9]+)*\Z/
-end
+end

lib/ancestry/has_ancestry.rb

@@ -14,6 +14,9 @@ def has_ancestry options = {}
     # Include dynamic class methods
     extend Ancestry::ClassMethods
 
+    # Include class methods that implement materialized path methods
+    extend Ancestry::MaterializedPath
+
     # Create ancestry column accessor and set to option or default
     cattr_accessor :ancestry_column
     self.ancestry_column = options[:ancestry_column] || :ancestry
@@ -38,11 +41,12 @@ def has_ancestry options = {}
 
     # Named scopes
     scope :roots, lambda { where(ancestry_column => nil) }
-    scope :ancestors_of, lambda { |object| where(to_node(object).ancestor_conditions) }
-    scope :children_of, lambda { |object| where(to_node(object).child_conditions) }
-    scope :descendants_of, lambda { |object| where(to_node(object).descendant_conditions) }
-    scope :subtree_of, lambda { |object| where(to_node(object).subtree_conditions) }
-    scope :siblings_of, lambda { |object| where(to_node(object).sibling_conditions) }
+    scope :ancestors_of, lambda { |object| where(ancestor_conditions(object)) }
+    scope :path_of, lambda { |object| where(path_conditions(object)) }
+    scope :children_of, lambda { |object| where(child_conditions(object)) }
+    scope :descendants_of, lambda { |object| where(descendant_conditions(object)) }
+    scope :subtree_of, lambda { |object| where(subtree_conditions(object)) }
+    scope :siblings_of, lambda { |object| where(sibling_conditions(object)) }
     scope :ordered_by_ancestry, lambda {
       if %w(mysql mysql2 sqlite postgresql).include?(connection.adapter_name.downcase) && ActiveRecord::VERSION::MAJOR >= 5
         reorder("coalesce(#{connection.quote_table_name(table_name)}.#{connection.quote_column_name(ancestry_column)}, '')")

lib/ancestry/instance_methods.rb

@@ -108,8 +108,7 @@ def ancestor_ids
     end
 
     def ancestor_conditions
-      t = get_arel_table
-      t[get_primary_key_column].in(ancestor_ids)
+      self.ancestry_base_class.ancestor_conditions(self)
     end
 
     def ancestors depth_options = {}
@@ -129,8 +128,7 @@ def path_ids
     end
 
     def path_conditions
-      t = get_arel_table
-      t[get_primary_key_column].in(path_ids)
+      self.ancestry_base_class.path_conditions(self)
     end
 
     def path depth_options = {}
@@ -197,8 +195,7 @@ def root_of?(node)
     # Children
 
     def child_conditions
-      t = get_arel_table
-      t[get_ancestry_column].eq(child_ancestry)
+      self.ancestry_base_class.child_conditions(self)
     end
 
     def children
@@ -226,8 +223,7 @@ def child_of?(node)
     # Siblings
 
     def sibling_conditions
-      t = get_arel_table
-      t[get_ancestry_column].eq(read_attribute(self.ancestry_base_class.ancestry_column))
+      self.ancestry_base_class.sibling_conditions(self)
     end
 
     def siblings
@@ -255,13 +251,7 @@ def sibling_of?(node)
     # Descendants
 
     def descendant_conditions
-      t = get_arel_table
-      # rails has case sensitive matching.
-      if ActiveRecord::VERSION::MAJOR >= 5
-        t[get_ancestry_column].matches("#{child_ancestry}/%", nil, true).or(t[get_ancestry_column].eq(child_ancestry))
-      else
-        t[get_ancestry_column].matches("#{child_ancestry}/%").or(t[get_ancestry_column].eq(child_ancestry))
-      end
+      self.ancestry_base_class.descendant_conditions(self)
     end
 
     def descendants depth_options = {}
@@ -279,8 +269,7 @@ def descendant_of?(node)
     # Subtree
 
     def subtree_conditions
-      t = get_arel_table
-      descendant_conditions.or(t[get_primary_key_column].eq(self.id))
+      self.ancestry_base_class.subtree_conditions(self)
     end
 
     def subtree depth_options = {}
@@ -332,17 +321,5 @@ def sane_ancestry?
     def unscoped_find id
       self.ancestry_base_class.unscoped { self.ancestry_base_class.find(id) }
     end
-
-    def get_arel_table
-      self.ancestry_base_class.arel_table
-    end
-
-    def get_primary_key_column
-      self.ancestry_base_class.primary_key.to_sym
-    end
-
-    def get_ancestry_column
-      self.ancestry_base_class.ancestry_column.to_sym
-    end
   end
 end

lib/ancestry/materialized_path.rb

@@ -0,0 +1,44 @@
+module Ancestry
+  module MaterializedPath
+    def ancestor_conditions(object)
+      t = arel_table
+      node = to_node(object)
+      t[primary_key].in(node.ancestor_ids)
+    end
+
+    def path_conditions(object)
+      t = arel_table
+      node = to_node(object)
+      t[primary_key].in(node.path_ids)
+    end
+
+    def child_conditions(object)
+      t = arel_table
+      node = to_node(object)
+      t[ancestry_column].eq(node.child_ancestry)
+    end
+
+    def descendant_conditions(object)
+      t = arel_table
+      node = to_node(object)
+      # rails has case sensitive matching.
+      if ActiveRecord::VERSION::MAJOR >= 5
+        t[ancestry_column].matches("#{node.child_ancestry}/%", nil, true).or(t[ancestry_column].eq(node.child_ancestry))
+      else
+        t[ancestry_column].matches("#{node.child_ancestry}/%").or(t[ancestry_column].eq(node.child_ancestry))
+      end
+    end
+
+    def subtree_conditions(object)
+      t = arel_table
+      node = to_node(object)
+      descendant_conditions(object).or(t[primary_key].eq(node.id))
+    end
+
+    def sibling_conditions(object)
+      t = arel_table
+      node = to_node(object)
+      t[ancestry_column].eq(node[ancestry_column])
+    end
+  end
+end