fixed ancestor/descendant relationships to be habtm

added test and doc for leaves (class scoped and instance methods)

Author: mceachen

README.rdoc

@@ -105,6 +105,7 @@ Note that the other columns will be null if nodes are created, other than auto-g
 [tag.root?] returns true if this is a root node
 [tag.child?] returns true if this is a child node. It has a parent.
 [tag.leaf?] returns true if this is a leaf node. It has no children.
+[tag.leaves] returns an array of all the nodes in self_and_descendants that are leaves.
 [tag.level] returns the level, or "generation", for this node in the tree. A root node = 0
 [tag.parent] returns the node's immediate parent
 [tag.children] returns an array of immediate children (just those in the next level).

lib/closure_tree/acts_as_tree.rb

@@ -33,23 +33,23 @@ def acts_as_tree options = {}
                :foreign_key => parent_column_name,
                :before_add => :add_child
 
-      has_many :ancestors_hierarchy,
-               :class_name => hierarchy_class_name,
-               :foreign_key => "descendant_id"
-
-      has_many :ancestors, :through => :ancestors_hierarchy,
-               :order => "generations asc"
-
-      has_many :descendants_hierarchy,
-               :class_name => hierarchy_class_name,
-               :foreign_key => "ancestor_id"
-
-      has_many :descendants, :through => :descendants_hierarchy,
-               :order => "generations asc"
+      has_and_belongs_to_many :ancestors,
+                              :class_name => base_class.to_s,
+                              :join_table => hierarchy_table_name,
+                              :foreign_key => "descendant_id",
+                              :association_foreign_key => "ancestor_id",
+                              :order => "generations asc"
+
+      has_and_belongs_to_many :descendants,
+                              :class_name => base_class.to_s,
+                              :join_table => hierarchy_table_name,
+                              :foreign_key => "ancestor_id",
+                              :association_foreign_key => "descendant_id",
+                              :order => "generations asc"
 
       scope :roots, where(parent_column_name => nil)
 
-      scope :leaves, includes(:descendants_hierarchy).where("#{hierarchy_table_name}.descendant_id is null")
+      scope :leaves, includes(:descendants).where("#{hierarchy_table_name}.descendant_id is null")
     end
   end
 
@@ -80,7 +80,8 @@ def leaf?
       end
 
       def leaves
-        self.class.scoped.includes(:descendants_hierarchy).where("#{hierarchy_table_name}.descendant_id is null and #{hierarchy_table_name}.ancestor_id = #{id}")
+        return [self] if leaf?
+        Tag.leaves.includes(:ancestors).where("ancestors_tags.id = ?", self.id)
       end
 
       # Returns true if this node has a parent, and is not a root.
@@ -215,8 +216,6 @@ def rebuild_node_and_children node
   # Mixed into both classes and instances to provide easy access to the column names
   module Columns
 
-    protected
-
     def parent_column_name
       closure_tree_options[:parent_column_name]
     end

lib/closure_tree/version.rb

@@ -1,3 +1,3 @@
 module ClosureTree
-  VERSION = "1.0.0.beta4" unless defined?(::ClosureTree::VERSION)
+  VERSION = "1.0.0.beta5" unless defined?(::ClosureTree::VERSION)
 end

test/dummy/test/unit/tag_test.rb

@@ -106,5 +106,13 @@ def test_root
     assert_equal tags(:grandparent), tags(:parent).root
     assert_equal tags(:grandparent), tags(:child).root
   end
+
+  def test_leaves
+    assert Tag.leaves.include? tags(:child)
+    assert Tag.leaves.select{|t|!t.leaf?}.empty?
+    assert_equal [tags(:child)], tags(:grandparent).leaves
+    assert_equal [tags(:child)], tags(:parent).leaves
+    assert_equal [tags(:child)], tags(:child).leaves
+  end
 end