Initial commit, moving from svn to git

README

@@ -0,0 +1,43 @@
+acts_as_tree_with_dotted_ids
+============================
+
+This is an extension to Rails good old acts_as_tree which uses an extra "dotted_ids" column 
+which stores the path of the node as string of ID joined by dots, hence the name.
+
+This solves performances issues related to in-database tree structure by allowing for O(1)
+ancestor/child verification and O(N) subtree access.
+
+The plugin adds the following instance methods:
+
+* ancestor_of?(node)
+* descendant_of?(node)
+* all_children
+
+As well as rewritten, optimized versions of 
+
+From the original acts_as_tree README:
+
+Specify this +acts_as+ extension if you want to model a tree structure by providing a parent association and a children
+association. This requires that you have a foreign key column, which by default is called +parent_id+.
+
+  class Category < ActiveRecord::Base
+    acts_as_tree :order => "name"
+  end
+
+  Example:
+  root
+   \_ child1
+        \_ subchild1
+        \_ subchild2
+
+  root      = Category.create("name" => "root")
+  child1    = root.children.create("name" => "child1")
+  subchild1 = child1.children.create("name" => "subchild1")
+
+  root.parent   # => nil
+  child1.parent # => root
+  root.children # => [child1]
+  root.children.first.children.first # => subchild1
+
+Copyright (c) 2007 David Heinemeier Hansson, released under the MIT license
+Copyright (c) 2008 Xavier Defrang, released under the MIT license

Rakefile

@@ -0,0 +1,25 @@
+
+$:.reject! { |e| e.include? 'TextMate' } 
+
+require 'rake'
+require 'rake/testtask'
+require 'rake/rdoctask'
+
+desc 'Default: run unit tests.'
+task :default => :test
+
+desc 'Test acts_as_tree plugin.'
+Rake::TestTask.new(:test) do |t|
+  t.libs << 'lib'
+  t.pattern = 'test/**/*_test.rb'
+  t.verbose = true
+end
+
+desc 'Generate documentation for acts_as_tree plugin.'
+Rake::RDocTask.new(:rdoc) do |rdoc|
+  rdoc.rdoc_dir = 'rdoc'
+  rdoc.title    = 'acts_as_tree_with_dotted_ids'
+  rdoc.options << '--line-numbers' << '--inline-source'
+  rdoc.rdoc_files.include('README')
+  rdoc.rdoc_files.include('lib/**/*.rb')
+end

init.rb

@@ -0,0 +1,2 @@
+require 'active_record/acts/tree_with_dotted_ids'
+ActiveRecord::Base.send :include, ActiveRecord::Acts::TreeWithDottedIds

lib/active_record/acts/tree_with_dotted_ids.rb

@@ -0,0 +1,212 @@
+module ActiveRecord
+  module Acts
+    module TreeWithDottedIds
+      def self.included(base)
+        base.extend(ClassMethods)
+      end
+
+      # Specify this +acts_as+ extension if you want to model a tree structure by providing a parent association and a children
+      # association. This requires that you have a foreign key column, which by default is called +parent_id+ and a string or text column called +dotted_ids+ which will be used to store the path to each node in the tree.
+      #
+      #   class Category < ActiveRecord::Base
+      #     acts_as_tree_with_dotted_ids :order => "name"
+      #   end
+      #
+      #   Example:
+      #   root
+      #    \_ child1
+      #         \_ subchild1
+      #         \_ subchild2
+      #
+      #   root      = Category.create("name" => "root")
+      #   child1    = root.children.create("name" => "child1")
+      #   subchild1 = child1.children.create("name" => "subchild1")
+      #
+      #   root.parent   # => nil
+      #   child1.parent # => root
+      #   root.children # => [child1]
+      #   root.children.first.children.first # => subchild1
+      #
+      # In addition to the parent and children associations, the following instance methods are added to the class
+      # after calling <tt>acts_as_tree</tt>:
+      # * <tt>siblings</tt> - Returns all the children of the parent, excluding the current node (<tt>[subchild2]</tt> when called on <tt>subchild1</tt>)
+      # * <tt>self_and_siblings</tt> - Returns all the children of the parent, including the current node (<tt>[subchild1, subchild2]</tt> when called on <tt>subchild1</tt>)
+      # * <tt>ancestors</tt> - Returns all the ancestors of the current node (<tt>[child1, root]</tt> when called on <tt>subchild2</tt>)
+      # * <tt>root</tt> - Returns the root of the current node (<tt>root</tt> when called on <tt>subchild2</tt>)
+      # * <tt>depth</tt> - Returns the depth of the current node starting from 0 as the depth of root nodes.
+      module ClassMethods
+        # Configuration options are:
+        #
+        # * <tt>foreign_key</tt> - specifies the column name to use for tracking of the tree (default: +parent_id+)
+        # * <tt>order</tt> - makes it possible to sort the children according to this SQL snippet.
+        # * <tt>counter_cache</tt> - keeps a count in a +children_count+ column if set to +true+ (default: +false+).
+        def acts_as_tree_with_dotted_ids(options = {}, &b)
+          configuration = { :foreign_key => "parent_id", :order => nil, :counter_cache => nil }
+          configuration.update(options) if options.is_a?(Hash)
+
+          belongs_to :parent, :class_name => name, :foreign_key => configuration[:foreign_key], :counter_cache => configuration[:counter_cache]
+
+
+          has_many :children, :class_name => name, :foreign_key => configuration[:foreign_key], 
+            :order => configuration[:order], :dependent => :destroy, &b
+
+          after_save                 :assign_dotted_ids
+          after_validation_on_update :update_dotted_ids
+
+          class_eval <<-EOV
+            include ActiveRecord::Acts::TreeWithDottedIds::InstanceMethods
+
+            def self.roots
+              res = find(:all, :conditions => "#{configuration[:foreign_key]} IS NULL", :order => #{configuration[:order].nil? ? "nil" : %Q{"#{configuration[:order]}"}})
+
+            end
+
+            def self.root
+              find(:first, :conditions => "#{configuration[:foreign_key]} IS NULL", :order => #{configuration[:order].nil? ? "nil" : %Q{"#{configuration[:order]}"}})
+            end
+            
+            def parent_foreign_key_changed?
+              #{configuration[:foreign_key]}_changed?
+            end
+            
+          EOV
+        end
+
+        # Performs a depth first traversal of the tree, yield each node to the given block 
+        def traverse(nodes = nil, &block)
+          nodes ||= self.roots
+          nodes.each do |node|
+            yield node
+            traverse(node.children, &block)
+          end
+        end
+
+        # Traverse the whole tree from roots to leaves and rebuild the dotted_ids path
+        # Call it from you migration to upgrade an existing acts_as_tree model.
+        def rebuild_dotted_ids!
+          transaction do
+            traverse { |node| node.dotted_ids = nil; node.save! }
+          end
+        end
+
+      end
+
+      module InstanceMethods
+
+        # Returns list of ancestors, starting from parent until root.
+        #
+        #   subchild1.ancestors # => [child1, root]
+        def ancestors
+          if self.dotted_ids
+            ids = self.dotted_ids.split('.')[0...-1]
+            self.class.find(:all, :conditions => {:id => ids}, :order => 'dotted_ids DESC')
+          else
+            node, nodes = self, []
+            nodes << node = node.parent while node.parent
+            nodes
+          end
+        end
+
+        # 
+        def self_and_ancestors
+          [self] + ancestors
+        end
+
+        # Returns the root node of the tree.
+        def root
+          if self.dotted_ids
+            self.class.find(self.dotted_ids.split('.').first)
+          else
+            node = self
+            node = node.parent while node.parent
+            node
+          end
+        end
+
+        # Returns all siblings of the current node.
+        #
+        #   subchild1.siblings # => [subchild2]
+        def siblings
+          self_and_siblings - [self]
+        end
+
+        # Returns all siblings and a reference to the current node.
+        #
+        #   subchild1.self_and_siblings # => [subchild1, subchild2]
+        def self_and_siblings
+          #parent ? parent.children : self.class.roots
+          self.class.find(:all, :conditions => {:parent_id => self.parent_id})
+        end
+
+        #
+        # root.ancestor_of?(subchild1) # => true
+        # subchild1.ancestor_of?(child1) # => false
+        def ancestor_of?(node)
+          node.dotted_ids.length > self.dotted_ids.length && node.dotted_ids.starts_with?(self.dotted_ids)
+        end
+
+        #
+        # subchild1.descendant_of?(child1) # => true
+        # root.descendant_of?(subchild1) # => false
+        def descendant_of?(node)
+          self.dotted_ids.length > node.dotted_ids.length && self.dotted_ids.starts_with?(node.dotted_ids)
+        end
+
+        # Returns all children of the current node
+        # root.all_children # => [child1, subchild1, subchild2]
+        def all_children
+          find_all_children_with_dotted_ids
+        end
+
+        # Returns all children of the current node
+        # root.self_and_all_children # => [root, child1, subchild1, subchild2]
+        def self_and_all_children
+          [self] + all_children
+        end
+
+        # Returns the depth of the node, root nodes have a depth of 0
+        def depth
+          self.dotted_ids.scan(/\./).size
+        end
+
+      protected
+
+        # Tranforms a dotted_id string into a pattern usable with a SQL LIKE statement
+        def dotted_id_like_pattern(prefix = nil)
+          (prefix || self.dotted_ids) + '.%'
+        end
+
+        # Find all children with the given dotted_id prefix
+        # *options* will be passed to to find(:all)
+        # FIXME: use merge_conditions when it will be part of the public API
+        def find_all_children_with_dotted_ids(prefix = nil, options = {})
+          self.class.find(:all, options.update(:conditions => ['dotted_ids LIKE ?', dotted_id_like_pattern(prefix)]))
+        end
+
+        # Generates the dotted_ids for this node
+        def build_dotted_ids
+          self.parent ? "#{self.parent.dotted_ids}.#{self.id}" : self.id.to_s
+        end
+
+        # After create, adds the dotted id's
+        def assign_dotted_ids
+          self.update_attribute(:dotted_ids, build_dotted_ids) if self.dotted_ids.blank?
+        end
+
+        # After validation on update, rebuild dotted ids if necessary
+        def update_dotted_ids
+          return unless parent_foreign_key_changed?
+          old_dotted_ids = self.dotted_ids
+          old_dotted_ids_regex = Regexp.new("^#{Regexp.escape(old_dotted_ids)}(.*)")
+          self.dotted_ids = build_dotted_ids
+          replace_pattern = "#{self.dotted_ids}\\1"          
+          find_all_children_with_dotted_ids(old_dotted_ids).each do |node|
+            new_dotted_ids = node.dotted_ids.gsub(old_dotted_ids_regex, replace_pattern)
+            node.update_attribute(:dotted_ids, new_dotted_ids)
+          end
+        end
+
+      end
+    end
+  end
+end