module Xylem::InstanceMethods

Public Instance Methods

ancestors() click to toggle source
# File lib/xylem.rb, line 5
def ancestors
  _xylem_query(:id, parent_id, :id, :parent_id, :desc)
end
descendants() click to toggle source
# File lib/xylem.rb, line 13
def descendants
  _xylem_query(:parent_id, id, :parent_id, :id, :asc)
end
leaf?() click to toggle source
# File lib/xylem.rb, line 41
def leaf?
  children.size == 0
end
leaves() click to toggle source
# File lib/xylem.rb, line 45
def leaves
  descendants.leaves
end
root() click to toggle source
# File lib/xylem.rb, line 21
def root
  ancestors.first
end
root?() click to toggle source
# File lib/xylem.rb, line 37
def root?
  parent.nil?
end
self_and_ancestors() click to toggle source
# File lib/xylem.rb, line 9
def self_and_ancestors
  _xylem_query(:id, id, :id, :parent_id, :desc)
end
self_and_children() click to toggle source
# File lib/xylem.rb, line 33
def self_and_children
  [self] + children
end
self_and_descendants() click to toggle source
# File lib/xylem.rb, line 17
def self_and_descendants
  _xylem_query(:id, id, :parent_id, :id, :asc)
end
self_and_siblings() click to toggle source
# File lib/xylem.rb, line 29
def self_and_siblings
  self.class.where(parent_id: parent_id)
end
siblings() click to toggle source
# File lib/xylem.rb, line 25
def siblings
  self.class.where(parent_id: parent_id).where.not(id: id)
end

Private Instance Methods

_xylem_query(where_col, where_val, join_lft_col, join_rgt_col, order_stmt) click to toggle source
# File lib/xylem.rb, line 51
def _xylem_query(where_col, where_val, join_lft_col, join_rgt_col, order_stmt)
  rcte = Arel::Table.new(:recusive_cte)
  table = self.class.arel_table
  i_select = table.project([table[Arel.star], Arel::Nodes::As.new(1, Arel::Nodes::SqlLiteral.new('level'))]).where(table[where_col].eq(where_val))
  r_select = table.project([table[Arel.star], Arel::Nodes::SqlLiteral.new('level + 1')]).join(rcte).on(table[join_lft_col].eq(rcte[join_rgt_col]))
  as_stmt = Arel::Nodes::As.new(rcte, i_select.union(:all, r_select))
  self.class.from(Arel::Nodes::TableAlias.new(rcte.project(Arel.star).with(:recursive, as_stmt), self.class.table_name).to_sql).order(level: order_stmt)
end