Module: CompositePrimaryKeys::ActiveRecord::QueryMethods

Included in:
CompositeRelation
Defined in:
lib/composite_primary_keys/relation/query_methods.rb

Instance Method Summary collapse

Instance Method Details

#reverse_sql_order(order_query) ⇒ Object 



4
5
6
7
8
9
10
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
 
# File 'lib/composite_primary_keys/relation/query_methods.rb', line 4

def reverse_sql_order(order_query)
  if order_query.empty?
    # CPK
    # return [arel_attribute(primary_key).desc] if primary_key

    if primary_key
      # break apart CPKs
      return primary_key.map do |key|
        arel_attribute(key).desc
      end
    else
      raise IrreversibleOrderError,
            "Relation has no current order and table has no primary key to be used as default order"
    end
  end

  order_query.flat_map do |o|
    order_query.flat_map do |o|
      case o
      when Arel::Attribute
        o.desc
      when Arel::Nodes::Ordering
        o.reverse
      when String
        if does_not_support_reverse?(o)
          raise IrreversibleOrderError, "Order #{o.inspect} can not be reversed automatically"
        end
        o.split(",").map! do |s|
          s.strip!
          s.gsub!(/\sasc\Z/i, " DESC") || s.gsub!(/\sdesc\Z/i, " ASC") || (s << " DESC")
        end
      else
        o
      end
    end
  end
end