Module: LookUp

Included in:
ActiveRecord::Base
Defined in:
lib/rails_look_up_table.rb

Instance Method Summary collapse

Instance Method Details

#lookup(table) ⇒ Object 



2
3
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
41
42
43
44
45
 
# File 'lib/rails_look_up_table.rb', line 2

def lookup(table)

  model = table.to_s.camelize.constantize
  foreign_key = table.to_s.downcase.concat('_id')

  # getter
  define_method table.to_s do
    model.try(:find_by_id, read_attribute(foreign_key.to_sym))
  end

  # setter that accepts :value, 'value' or Value object
  define_method "#{table.to_s}=" do |value|
    record = value.try(:is_a?, model) ? value : model.try(:find_or_create_by_name, value.to_s)
    write_attribute(foreign_key, record.id)
    unless respond_to?("#{record.name.downcase}?".to_sym)
      instance_exec(self) do |instance|
        instance.class.send(:define_method,"#{record.name.downcase}?") do
           instance.send(foreign_key.to_sym) == record.id
        end
      end
      self.class.singleton_class.instance_eval do
        define_method record.name.downcase.pluralize do
          where(:status_id => record.id )
        end
      end
    end
  end

  # getter for dirty attributes
  define_method "#{table.to_s}_was" do
    model.try(:find_by_id, attribute_was(foreign_key))
  end

  model.all.each do |record|
    # returns collection of each lookup object eg Model.todos
    define_singleton_method record.name.downcase.pluralize do
      where(foreign_key.to_sym => record.id )
    end
    # adds boolean methods to check whether an object is of lookup type eg. @instance.pending?
    define_method "#{record.name.downcase}?" do
      send(foreign_key.to_sym) == record.id
    end
  end
end