Mercurial > hg > soundsoftware-site
diff .svn/pristine/fd/fd672f720e53aab0a0184fd9c83dcdbc26d28825.svn-base @ 1298:4f746d8966dd redmine_2.3_integration
Merge from redmine-2.3 branch to create new branch redmine-2.3-integration
author | Chris Cannam |
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date | Fri, 14 Jun 2013 09:28:30 +0100 |
parents | 622f24f53b42 |
children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/.svn/pristine/fd/fd672f720e53aab0a0184fd9c83dcdbc26d28825.svn-base Fri Jun 14 09:28:30 2013 +0100 @@ -0,0 +1,601 @@ +module CollectiveIdea #:nodoc: + module Acts #:nodoc: + module NestedSet #:nodoc: + + # This acts provides Nested Set functionality. Nested Set is a smart way to implement + # an _ordered_ tree, with the added feature that you can select the children and all of their + # descendants with a single query. The drawback is that insertion or move need some complex + # sql queries. But everything is done here by this module! + # + # Nested sets are appropriate each time you want either an orderd tree (menus, + # commercial categories) or an efficient way of querying big trees (threaded posts). + # + # == API + # + # Methods names are aligned with acts_as_tree as much as possible to make replacment from one + # by another easier. + # + # item.children.create(:name => "child1") + # + + # Configuration options are: + # + # * +:parent_column+ - specifies the column name to use for keeping the position integer (default: parent_id) + # * +:left_column+ - column name for left boundry data, default "lft" + # * +:right_column+ - column name for right boundry data, default "rgt" + # * +:scope+ - restricts what is to be considered a list. Given a symbol, it'll attach "_id" + # (if it hasn't been already) and use that as the foreign key restriction. You + # can also pass an array to scope by multiple attributes. + # Example: <tt>acts_as_nested_set :scope => [:notable_id, :notable_type]</tt> + # * +:dependent+ - behavior for cascading destroy. If set to :destroy, all the + # child objects are destroyed alongside this object by calling their destroy + # method. If set to :delete_all (default), all the child objects are deleted + # without calling their destroy method. + # * +:counter_cache+ adds a counter cache for the number of children. + # defaults to false. + # Example: <tt>acts_as_nested_set :counter_cache => :children_count</tt> + # + # See CollectiveIdea::Acts::NestedSet::Model::ClassMethods for a list of class methods and + # CollectiveIdea::Acts::NestedSet::Model for a list of instance methods added + # to acts_as_nested_set models + def acts_as_nested_set(options = {}) + options = { + :parent_column => 'parent_id', + :left_column => 'lft', + :right_column => 'rgt', + :dependent => :delete_all, # or :destroy + :counter_cache => false, + :order => 'id' + }.merge(options) + + if options[:scope].is_a?(Symbol) && options[:scope].to_s !~ /_id$/ + options[:scope] = "#{options[:scope]}_id".intern + end + + class_attribute :acts_as_nested_set_options + self.acts_as_nested_set_options = options + + include CollectiveIdea::Acts::NestedSet::Model + include Columns + extend Columns + + belongs_to :parent, :class_name => self.base_class.to_s, + :foreign_key => parent_column_name, + :counter_cache => options[:counter_cache], + :inverse_of => :children + has_many :children, :class_name => self.base_class.to_s, + :foreign_key => parent_column_name, :order => left_column_name, + :inverse_of => :parent, + :before_add => options[:before_add], + :after_add => options[:after_add], + :before_remove => options[:before_remove], + :after_remove => options[:after_remove] + + attr_accessor :skip_before_destroy + + before_create :set_default_left_and_right + before_save :store_new_parent + after_save :move_to_new_parent + before_destroy :destroy_descendants + + # no assignment to structure fields + [left_column_name, right_column_name].each do |column| + module_eval <<-"end_eval", __FILE__, __LINE__ + def #{column}=(x) + raise ActiveRecord::ActiveRecordError, "Unauthorized assignment to #{column}: it's an internal field handled by acts_as_nested_set code, use move_to_* methods instead." + end + end_eval + end + + define_model_callbacks :move + end + + module Model + extend ActiveSupport::Concern + + module ClassMethods + # Returns the first root + def root + roots.first + end + + def roots + where(parent_column_name => nil).order(quoted_left_column_name) + end + + def leaves + where("#{quoted_right_column_name} - #{quoted_left_column_name} = 1").order(quoted_left_column_name) + end + + def valid? + left_and_rights_valid? && no_duplicates_for_columns? && all_roots_valid? + end + + def left_and_rights_valid? + joins("LEFT OUTER JOIN #{quoted_table_name} AS parent ON " + + "#{quoted_table_name}.#{quoted_parent_column_name} = parent.#{primary_key}"). + where( + "#{quoted_table_name}.#{quoted_left_column_name} IS NULL OR " + + "#{quoted_table_name}.#{quoted_right_column_name} IS NULL OR " + + "#{quoted_table_name}.#{quoted_left_column_name} >= " + + "#{quoted_table_name}.#{quoted_right_column_name} OR " + + "(#{quoted_table_name}.#{quoted_parent_column_name} IS NOT NULL AND " + + "(#{quoted_table_name}.#{quoted_left_column_name} <= parent.#{quoted_left_column_name} OR " + + "#{quoted_table_name}.#{quoted_right_column_name} >= parent.#{quoted_right_column_name}))" + ).count == 0 + end + + def no_duplicates_for_columns? + scope_string = Array(acts_as_nested_set_options[:scope]).map do |c| + connection.quote_column_name(c) + end.push(nil).join(", ") + [quoted_left_column_name, quoted_right_column_name].all? do |column| + # No duplicates + select("#{scope_string}#{column}, COUNT(#{column})"). + group("#{scope_string}#{column}"). + having("COUNT(#{column}) > 1"). + first.nil? + end + end + + # Wrapper for each_root_valid? that can deal with scope. + def all_roots_valid? + if acts_as_nested_set_options[:scope] + roots.group(scope_column_names).group_by{|record| scope_column_names.collect{|col| record.send(col.to_sym)}}.all? do |scope, grouped_roots| + each_root_valid?(grouped_roots) + end + else + each_root_valid?(roots) + end + end + + def each_root_valid?(roots_to_validate) + left = right = 0 + roots_to_validate.all? do |root| + (root.left > left && root.right > right).tap do + left = root.left + right = root.right + end + end + end + + # Rebuilds the left & rights if unset or invalid. + # Also very useful for converting from acts_as_tree. + def rebuild!(validate_nodes = true) + # Don't rebuild a valid tree. + return true if valid? + + scope = lambda{|node|} + if acts_as_nested_set_options[:scope] + scope = lambda{|node| + scope_column_names.inject(""){|str, column_name| + str << "AND #{connection.quote_column_name(column_name)} = #{connection.quote(node.send(column_name.to_sym))} " + } + } + end + indices = {} + + set_left_and_rights = lambda do |node| + # set left + node[left_column_name] = indices[scope.call(node)] += 1 + # find + where(["#{quoted_parent_column_name} = ? #{scope.call(node)}", node]).order(acts_as_nested_set_options[:order]).each{|n| set_left_and_rights.call(n) } + # set right + node[right_column_name] = indices[scope.call(node)] += 1 + node.save!(:validate => validate_nodes) + end + + # Find root node(s) + root_nodes = where("#{quoted_parent_column_name} IS NULL").order(acts_as_nested_set_options[:order]).each do |root_node| + # setup index for this scope + indices[scope.call(root_node)] ||= 0 + set_left_and_rights.call(root_node) + end + end + + # Iterates over tree elements and determines the current level in the tree. + # Only accepts default ordering, odering by an other column than lft + # does not work. This method is much more efficent than calling level + # because it doesn't require any additional database queries. + # + # Example: + # Category.each_with_level(Category.root.self_and_descendants) do |o, level| + # + def each_with_level(objects) + path = [nil] + objects.each do |o| + if o.parent_id != path.last + # we are on a new level, did we decent or ascent? + if path.include?(o.parent_id) + # remove wrong wrong tailing paths elements + path.pop while path.last != o.parent_id + else + path << o.parent_id + end + end + yield(o, path.length - 1) + end + end + end + + # Any instance method that returns a collection makes use of Rails 2.1's named_scope (which is bundled for Rails 2.0), so it can be treated as a finder. + # + # category.self_and_descendants.count + # category.ancestors.find(:all, :conditions => "name like '%foo%'") + + # Value of the parent column + def parent_id + self[parent_column_name] + end + + # Value of the left column + def left + self[left_column_name] + end + + # Value of the right column + def right + self[right_column_name] + end + + # Returns true if this is a root node. + def root? + parent_id.nil? + end + + def leaf? + new_record? || (right - left == 1) + end + + # Returns true is this is a child node + def child? + !parent_id.nil? + end + + # Returns root + def root + self_and_ancestors.where(parent_column_name => nil).first + end + + # Returns the array of all parents and self + def self_and_ancestors + nested_set_scope.where([ + "#{self.class.quoted_table_name}.#{quoted_left_column_name} <= ? AND #{self.class.quoted_table_name}.#{quoted_right_column_name} >= ?", left, right + ]) + end + + # Returns an array of all parents + def ancestors + without_self self_and_ancestors + end + + # Returns the array of all children of the parent, including self + def self_and_siblings + nested_set_scope.where(parent_column_name => parent_id) + end + + # Returns the array of all children of the parent, except self + def siblings + without_self self_and_siblings + end + + # Returns a set of all of its nested children which do not have children + def leaves + descendants.where("#{self.class.quoted_table_name}.#{quoted_right_column_name} - #{self.class.quoted_table_name}.#{quoted_left_column_name} = 1") + end + + # Returns the level of this object in the tree + # root level is 0 + def level + parent_id.nil? ? 0 : ancestors.count + end + + # Returns a set of itself and all of its nested children + def self_and_descendants + nested_set_scope.where([ + "#{self.class.quoted_table_name}.#{quoted_left_column_name} >= ? AND #{self.class.quoted_table_name}.#{quoted_right_column_name} <= ?", left, right + ]) + end + + # Returns a set of all of its children and nested children + def descendants + without_self self_and_descendants + end + + def is_descendant_of?(other) + other.left < self.left && self.left < other.right && same_scope?(other) + end + + def is_or_is_descendant_of?(other) + other.left <= self.left && self.left < other.right && same_scope?(other) + end + + def is_ancestor_of?(other) + self.left < other.left && other.left < self.right && same_scope?(other) + end + + def is_or_is_ancestor_of?(other) + self.left <= other.left && other.left < self.right && same_scope?(other) + end + + # Check if other model is in the same scope + def same_scope?(other) + Array(acts_as_nested_set_options[:scope]).all? do |attr| + self.send(attr) == other.send(attr) + end + end + + # Find the first sibling to the left + def left_sibling + siblings.where(["#{self.class.quoted_table_name}.#{quoted_left_column_name} < ?", left]). + order("#{self.class.quoted_table_name}.#{quoted_left_column_name} DESC").last + end + + # Find the first sibling to the right + def right_sibling + siblings.where(["#{self.class.quoted_table_name}.#{quoted_left_column_name} > ?", left]).first + end + + # Shorthand method for finding the left sibling and moving to the left of it. + def move_left + move_to_left_of left_sibling + end + + # Shorthand method for finding the right sibling and moving to the right of it. + def move_right + move_to_right_of right_sibling + end + + # Move the node to the left of another node (you can pass id only) + def move_to_left_of(node) + move_to node, :left + end + + # Move the node to the left of another node (you can pass id only) + def move_to_right_of(node) + move_to node, :right + end + + # Move the node to the child of another node (you can pass id only) + def move_to_child_of(node) + move_to node, :child + end + + # Move the node to root nodes + def move_to_root + move_to nil, :root + end + + def move_possible?(target) + self != target && # Can't target self + same_scope?(target) && # can't be in different scopes + # !(left..right).include?(target.left..target.right) # this needs tested more + # detect impossible move + !((left <= target.left && right >= target.left) or (left <= target.right && right >= target.right)) + end + + def to_text + self_and_descendants.map do |node| + "#{'*'*(node.level+1)} #{node.id} #{node.to_s} (#{node.parent_id}, #{node.left}, #{node.right})" + end.join("\n") + end + + protected + + def without_self(scope) + scope.where(["#{self.class.quoted_table_name}.#{self.class.primary_key} != ?", self]) + end + + # All nested set queries should use this nested_set_scope, which performs finds on + # the base ActiveRecord class, using the :scope declared in the acts_as_nested_set + # declaration. + def nested_set_scope(options = {}) + options = {:order => "#{self.class.quoted_table_name}.#{quoted_left_column_name}"}.merge(options) + scopes = Array(acts_as_nested_set_options[:scope]) + options[:conditions] = scopes.inject({}) do |conditions,attr| + conditions.merge attr => self[attr] + end unless scopes.empty? + self.class.base_class.scoped options + end + + def store_new_parent + @move_to_new_parent_id = send("#{parent_column_name}_changed?") ? parent_id : false + true # force callback to return true + end + + def move_to_new_parent + if @move_to_new_parent_id.nil? + move_to_root + elsif @move_to_new_parent_id + move_to_child_of(@move_to_new_parent_id) + end + end + + # on creation, set automatically lft and rgt to the end of the tree + def set_default_left_and_right + highest_right_row = nested_set_scope(:order => "#{quoted_right_column_name} desc").limit(1).lock(true).first + maxright = highest_right_row ? (highest_right_row[right_column_name] || 0) : 0 + # adds the new node to the right of all existing nodes + self[left_column_name] = maxright + 1 + self[right_column_name] = maxright + 2 + end + + def in_tenacious_transaction(&block) + retry_count = 0 + begin + transaction(&block) + rescue ActiveRecord::StatementInvalid => error + raise unless connection.open_transactions.zero? + raise unless error.message =~ /Deadlock found when trying to get lock|Lock wait timeout exceeded/ + raise unless retry_count < 10 + retry_count += 1 + logger.info "Deadlock detected on retry #{retry_count}, restarting transaction" + sleep(rand(retry_count)*0.1) # Aloha protocol + retry + end + end + + # Prunes a branch off of the tree, shifting all of the elements on the right + # back to the left so the counts still work. + def destroy_descendants + return if right.nil? || left.nil? || skip_before_destroy + + in_tenacious_transaction do + reload_nested_set + # select the rows in the model that extend past the deletion point and apply a lock + self.class.base_class. + select("id"). + where("#{quoted_left_column_name} >= ?", left). + lock(true). + all + + if acts_as_nested_set_options[:dependent] == :destroy + descendants.each do |model| + model.skip_before_destroy = true + model.destroy + end + else + nested_set_scope.delete_all( + ["#{quoted_left_column_name} > ? AND #{quoted_right_column_name} < ?", + left, right] + ) + end + + # update lefts and rights for remaining nodes + diff = right - left + 1 + nested_set_scope.update_all( + ["#{quoted_left_column_name} = (#{quoted_left_column_name} - ?)", diff], + ["#{quoted_left_column_name} > ?", right] + ) + nested_set_scope.update_all( + ["#{quoted_right_column_name} = (#{quoted_right_column_name} - ?)", diff], + ["#{quoted_right_column_name} > ?", right] + ) + +reload + # Don't allow multiple calls to destroy to corrupt the set + self.skip_before_destroy = true + end + end + + # reload left, right, and parent + def reload_nested_set + reload( + :select => "#{quoted_left_column_name}, #{quoted_right_column_name}, #{quoted_parent_column_name}", + :lock => true + ) + end + + def move_to(target, position) + raise ActiveRecord::ActiveRecordError, "You cannot move a new node" if self.new_record? + run_callbacks :move do + in_tenacious_transaction do + if target.is_a? self.class.base_class + target.reload_nested_set + elsif position != :root + # load object if node is not an object + target = nested_set_scope.find(target) + end + self.reload_nested_set + + unless position == :root || move_possible?(target) + raise ActiveRecord::ActiveRecordError, "Impossible move, target node cannot be inside moved tree." + end + + bound = case position + when :child; target[right_column_name] + when :left; target[left_column_name] + when :right; target[right_column_name] + 1 + when :root; 1 + else raise ActiveRecord::ActiveRecordError, "Position should be :child, :left, :right or :root ('#{position}' received)." + end + + if bound > self[right_column_name] + bound = bound - 1 + other_bound = self[right_column_name] + 1 + else + other_bound = self[left_column_name] - 1 + end + + # there would be no change + return if bound == self[right_column_name] || bound == self[left_column_name] + + # we have defined the boundaries of two non-overlapping intervals, + # so sorting puts both the intervals and their boundaries in order + a, b, c, d = [self[left_column_name], self[right_column_name], bound, other_bound].sort + + # select the rows in the model between a and d, and apply a lock + self.class.base_class.select('id').lock(true).where( + ["#{quoted_left_column_name} >= :a and #{quoted_right_column_name} <= :d", {:a => a, :d => d}] + ) + + new_parent = case position + when :child; target.id + when :root; nil + else target[parent_column_name] + end + + self.nested_set_scope.update_all([ + "#{quoted_left_column_name} = CASE " + + "WHEN #{quoted_left_column_name} BETWEEN :a AND :b " + + "THEN #{quoted_left_column_name} + :d - :b " + + "WHEN #{quoted_left_column_name} BETWEEN :c AND :d " + + "THEN #{quoted_left_column_name} + :a - :c " + + "ELSE #{quoted_left_column_name} END, " + + "#{quoted_right_column_name} = CASE " + + "WHEN #{quoted_right_column_name} BETWEEN :a AND :b " + + "THEN #{quoted_right_column_name} + :d - :b " + + "WHEN #{quoted_right_column_name} BETWEEN :c AND :d " + + "THEN #{quoted_right_column_name} + :a - :c " + + "ELSE #{quoted_right_column_name} END, " + + "#{quoted_parent_column_name} = CASE " + + "WHEN #{self.class.base_class.primary_key} = :id THEN :new_parent " + + "ELSE #{quoted_parent_column_name} END", + {:a => a, :b => b, :c => c, :d => d, :id => self.id, :new_parent => new_parent} + ]) + end + target.reload_nested_set if target + self.reload_nested_set + end + end + + end + + # Mixed into both classes and instances to provide easy access to the column names + module Columns + def left_column_name + acts_as_nested_set_options[:left_column] + end + + def right_column_name + acts_as_nested_set_options[:right_column] + end + + def parent_column_name + acts_as_nested_set_options[:parent_column] + end + + def scope_column_names + Array(acts_as_nested_set_options[:scope]) + end + + def quoted_left_column_name + connection.quote_column_name(left_column_name) + end + + def quoted_right_column_name + connection.quote_column_name(right_column_name) + end + + def quoted_parent_column_name + connection.quote_column_name(parent_column_name) + end + + def quoted_scope_column_names + scope_column_names.collect {|column_name| connection.quote_column_name(column_name) } + end + end + + end + end +end