Module: Torque::PostgreSQL::Base::ClassMethods

Defined in:
lib/torque/postgresql/base.rb

Instance Method Summary collapse

Instance Method Details

#inherited(subclass) ⇒ Object

Wenever it’s inherited, add a new list of auxiliary statements It also adds an auxiliary statement to load inherited records’ relname



11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/torque/postgresql/base.rb', line 11

def inherited(subclass)
  super

  subclass.class_attribute(:auxiliary_statements_list)
  subclass.auxiliary_statements_list = Hash.new
  record_class = ActiveRecord::Relation._record_class_attribute

  # Define helper methods to return the class of the given records
  subclass.auxiliary_statement record_class do |cte|
    pg_class = ::Arel::Table.new('pg_class')
    arel_query = ::Arel::SelectManager.new(pg_class)
    arel_query.project(pg_class['oid'], pg_class['relname'].as(record_class.to_s))

    cte.query 'pg_class', arel_query.to_sql
    cte.attributes col(record_class) => record_class
    cte.join tableoid: :oid
  end

  # Define the dynamic attribute that returns the same information as
  # the one provided by the auxiliary statement
  subclass.dynamic_attribute(record_class) do
    next self.class.table_name unless self.class.physically_inheritances?

    pg_class = ::Arel::Table.new('pg_class')
    source = ::Arel::Table.new(subclass.table_name, as: 'source')
    quoted_id = ::Arel::Nodes::Quoted.new(self.class.connection.quote(id))

    query = ::Arel::SelectManager.new(pg_class)
    query.join(source).on(pg_class['oid'].eq(source['tableoid']))
    query.where(source[subclass.primary_key].eq(quoted_id))
    query.project(pg_class['relname'])

    self.class.connection.select_value(query)
  end
end