Module: ClosureTree::NumericDeterministicOrdering

Extended by:
ActiveSupport::Concern
Defined in:
lib/closure_tree/numeric_deterministic_ordering.rb

Defined Under Namespace

Modules: ClassMethods

Instance Method Summary collapse

Instance Method Details

#_ct_reorder_children(minimum_sort_order_value = nil) ⇒ Object


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 24

def _ct_reorder_children(minimum_sort_order_value = nil)
  _ct.reorder_with_parent_id(_ct_id, minimum_sort_order_value)
end

#_ct_reorder_prior_siblings_if_parent_changedObject


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 12

def _ct_reorder_prior_siblings_if_parent_changed
  if attribute_changed?(_ct.parent_column_name) && !@was_new_record
    was_parent_id = attribute_was(_ct.parent_column_name)
    _ct.reorder_with_parent_id(was_parent_id)
  end
end

#_ct_reorder_siblings(minimum_sort_order_value = nil) ⇒ Object


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 19

def _ct_reorder_siblings(minimum_sort_order_value = nil)
  _ct.reorder_with_parent_id(_ct_parent_id, minimum_sort_order_value)
  reload unless destroyed?
end

#add_sibling(sibling, add_after = true) ⇒ Object


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 98

def add_sibling(sibling, add_after = true)
  fail "can't add self as sibling" if self == sibling

  # Make sure self isn't dirty, because we're going to call reload:
  save

  _ct.with_advisory_lock do
    prior_sibling_parent = sibling.parent
    reorder_from_value = if prior_sibling_parent == self.parent
      [self.order_value, sibling.order_value].compact.min
    else
      self.order_value
    end

    sibling.order_value = self.order_value
    sibling.parent = self.parent
    sibling._ct_skip_sort_order_maintenance!
    sibling.save # may be a no-op

    _ct_reorder_siblings(reorder_from_value)

    # The sort order should be correct now except for self and sibling, which may need to flip:
    sibling_is_after = self.reload.order_value < sibling.reload.order_value
    if add_after != sibling_is_after
      # We need to flip the sort orders:
      self_ov, sib_ov = self.order_value, sibling.order_value
      update_order_value(sib_ov)
      sibling.update_order_value(self_ov)
    end

    if prior_sibling_parent != self.parent
      prior_sibling_parent.try(:_ct_reorder_children)
    end
    sibling
  end
end

#append_child(child_node) ⇒ Object


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 77

def append_child(child_node)
  add_child(child_node)
end

#append_sibling(sibling_node) ⇒ Object


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 90

def append_sibling(sibling_node)
  add_sibling(sibling_node, true)
end

#prepend_child(child_node) ⇒ Object


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 81

def prepend_child(child_node)
  child_node.order_value = -1
  child_node.parent = self
  child_node._ct_skip_sort_order_maintenance!
  child_node.save
  _ct_reorder_children
  child_node.reload
end

#prepend_sibling(sibling_node) ⇒ Object


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 94

def prepend_sibling(sibling_node)
  add_sibling(sibling_node, false)
end

#self_and_descendants_preorderedObject


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# File 'lib/closure_tree/numeric_deterministic_ordering.rb', line 28

def self_and_descendants_preordered
  # TODO: raise NotImplementedError if sort_order is not numeric and not null?
  h = _ct.connection.select_one(<<-SQL)
    SELECT
      count(*) as total_descendants,
      max(generations) as max_depth
    FROM #{_ct.quoted_hierarchy_table_name}
    WHERE ancestor_id = #{_ct.quote(self.id)}
  SQL
  join_sql = <<-SQL
    JOIN #{_ct.quoted_hierarchy_table_name} anc_hier
      ON anc_hier.descendant_id = #{_ct.quoted_hierarchy_table_name}.descendant_id
    JOIN #{_ct.quoted_table_name} anc
      ON anc.#{_ct.quoted_id_column_name} = anc_hier.ancestor_id
    JOIN #{_ct.quoted_hierarchy_table_name} depths
      ON depths.ancestor_id = #{_ct.quote(self.id)} AND depths.descendant_id = anc.#{_ct.quoted_id_column_name}
  SQL
  node_score = "(1 + anc.#{_ct.quoted_order_column(false)}) * " +
    "power(#{h['total_descendants']}, #{h['max_depth'].to_i + 1} - depths.generations)"
  order_by = "sum(#{node_score})"
  self_and_descendants.joins(join_sql).group("#{_ct.quoted_table_name}.#{_ct.quoted_id_column_name}").reorder(order_by)
end