Module: OrderQuery::NullsDirection

Defined in:
lib/order_query/nulls_direction.rb

Overview

Handles nulls :first and :last direction.

Constant Summary collapse

DIRECTIONS = 
%i[first last].freeze

Class Method Summary collapse

Class Method Details

.all ⇒ Object 



10
11
12
 
# File 'lib/order_query/nulls_direction.rb', line 10

def all
  DIRECTIONS
end

.connection_adapter(scope) ⇒ Object 



44
45
46
47
48
49
50
51
 
# File 'lib/order_query/nulls_direction.rb', line 44

def connection_adapter(scope)
  if scope.respond_to?(:connection_db_config)
    # Rails >= 6.1.0
    scope.connection_db_config.adapter
  else
    scope.connection_config[:adapter]
  end
end

.default(scope, dir) ⇒ :first, :last

Returns the default nulls order, based on the given scope’s connection adapter name.

Parameters:

  • scope (ActiveRecord::Relation)
  • dir (:asc, :desc)

Returns:

  • (:first, :last) —

    the default nulls order, based on the given scope’s connection adapter name.



34
35
36
37
38
39
40
41
42
 
# File 'lib/order_query/nulls_direction.rb', line 34

def default(scope, dir)
  case connection_adapter(scope)
  when /mysql|maria|sqlite|sqlserver/i
    (dir == :asc ? :first : :last)
  else
    # Oracle, Postgres
    (dir == :asc ? :last : :first)
  end
end

.parse!(direction) ⇒ :first, :last

Parameters:

  • direction (:first, :last)

Returns:

  • (:first, :last)

Raises:

  • (ArgumentError) 


23
24
25
26
27
28
 
# File 'lib/order_query/nulls_direction.rb', line 23

def parse!(direction)
  all.include?(direction) && direction or
    fail ArgumentError,
         "`nulls` must be in #{all.map(&:inspect).join(', ')}, "\
         "is #{direction.inspect}"
end

.reverse(direction) ⇒ :first, :last

Parameters:

  • direction (:first, :last)

Returns:

  • (:first, :last) 


16
17
18
 
# File 'lib/order_query/nulls_direction.rb', line 16

def reverse(direction)
  all[(all.index(direction) + 1) % 2].to_sym
end