Use acts_as_nested_set instead of acts_as_tree for project hierarchy.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/branches/work@2149 e93f8b46-1217-0410-a6f0-8f06a7374b81

nested_projects/db/migrate/102_add_projects_lft_and_rgt.rb

@@ -0,0 +1,11 @@
+class AddProjectsLftAndRgt < ActiveRecord::Migration
+  def self.up
+    add_column :projects, :lft, :integer
+    add_column :projects, :rgt, :integer
+  end
+
+  def self.down
+    remove_column :projects, :lft
+    remove_column :projects, :rgt
+  end
+end

nested_projects/db/migrate/103_build_projects_tree.rb

@@ -0,0 +1,8 @@
+class BuildProjectsTree < ActiveRecord::Migration
+  def self.up
+    Project.rebuild!
+  end
+
+  def self.down
+  end
+end