nested_set
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20 hours ago •
skyeagle
skyeagle
Error: Unauthorized assignment to lft: it's an internal field handled by acts_as_nested_set code, use move_to_* methods instead
I am getting this error: "Unauthorized assignment to lft: it's an internal field handled by acts_as_nested_set code, use move_to_* methods instead." whilst running this code: rake redmine:merge_redmine RAILS_ENV=production (the aim to to merge 2 databases with different data and both databases have the same schema. ) via Bitnami Redmine Stacks version 2.2.1-0 in windows 7 platform and on windows server 2008 r2. I am very new to Ruby on Rails and do not know what the error means and how to fix it. Any pointers / guidance would be very much appreciated!
Thank you for you time!
First of all. The redmine uses custom vendored awesome nested set plugin and it is not related to this one. This error mean that you are trying to manipulate with field of db that is used only for internal needs of the plugin.
Thank you skyeagle for your comment. What do I need to do or how to fix it? Any pointers is very much appreciated. :) Have a good day.
Take a look on your code, search for accessors like lft=, rgt=. Replace them with the self['lft'] = and self['rgt']= accordingly.
UPD: self['rgt']= will be properly
I have followed your instructions and the above error is solved, however its given me a different error :( and it did stop 2 of my Redmine services. If you dont mind, please have a quick at this code I have (original code:)
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").find(:first, :limit => 1,:lock => true )
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.find(:all,
:select => "id",
:conditions => ["#{quoted_left_column_name} >= ?", left],
:lock => true
)
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
I have edited: 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").find(:first, :limit => 1,:lock => true )
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.find(:all,
:select => "id",
:conditions => ["#{quoted_left_column_name} >= ?", left],
:lock => true
)
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
i have edited line 44, 45, 419 and 420 with your instructions, have I got this right?
the above screen dump is the new error complaining about [] is missing. Could you please give me more pointers? Thank you very much for your time, very much appreciated.
You are doing something wrong. When I said your code I meant your rake task that are doing merge but not the plugin functionality. It would be very dangerous to do modifications without understanding what are you doing. I will recommend you to contact with somebody who has real experience in programming.
Thank you skyeagle for the comment. I have tried contacting everyone on internet to help me and no luck. Was given some links and it helped me to get to this last stage which is the only problem I have. Do you know anyone who can help me? Or can you offer me more guidance?
Thank you so much for replying.
I'm really sorry but your problem is more complicated and needs in direct participation of professional.