Module: Defaulter::HasDefault

Defined in:
lib/defaulter/has_default.rb

Instance Method Summary collapse

Instance Method Details

#has_default(model, *args) ⇒ Object 



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
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
 
# File 'lib/defaulter/has_default.rb', line 3

def has_default(model, *args)
  resource      = model.to_sym
  options       = args.extract_options!
  resources     = resource.to_s.pluralize.to_sym
  column_name   = options.delete(:column) || :prime
  column_setter = "#{column_name}=".to_sym

  # Unused
  # method        = "default_#{resource}_column".to_sym
  # class_variable_set("@@#{method}".to_sym, column_name.freeze)
  # define_singleton_method(method) { class_variable_get("@@#{method}".to_sym) }

  def load_method
    @@load_method ||= (Gem::Version.new('4.0.0') >=
      Gem::Version.new(Rails.version)) ? :all : :load
  end

  has_many resources, options do

    define_method(:default) { where(column_name => true).limit(1)[0] }

    define_method(:default=) do |record|
      records = self.send(load_method)

      if records.include?(record)
        ActiveRecord::Base.transaction do
          # Marking existing record as default
          records.map { |r| r.update_attribute(column_name, false) if
            r.send(column_name) }
          record.update_attribute(column_name, true)
        end
      else
        raise ActiveRecord::RecordNotFound, "Record not in collection"
      end
    end

    define_method(:<<) do |records|
      records_on_db = self.send(load_method)
      none_on_db    = records_on_db.empty?
      default_on_db = records_on_db.select { |r| r.send(column_name) }

      case records.class.name
      when 'Array'
        # Find out if any default records have been given
        default_records = records.select do |r|
          r.send(column_name)
        end

        # Mark the first record as default iff:
        # 1. None exist on DB
        # 2. Given array of records is NOT empty
        # 3. Given records have no default record marked
        records[0].send(column_setter, true) if
          none_on_db &&
          !records.empty? &&
          default_records.empty?

        # Candidate default record if none given or none on db
        default_record = records.delete(default_records[-1])

        ActiveRecord::Base.transaction do
          if default_record.blank?
            self.concat(records) unless records.blank?
          else
            records.each { |r| r.send(column_setter, false) }

            default_on_db.each do |r|
              r.update_attribute(column_name, false)
            end

            self.concat(records + [default_record])
          end
        end
      else
        unless records.blank?
          records.send(column_setter, true) if default_on_db.blank?

          ActiveRecord::Base.transaction do
            if records.send(column_name)
              default_on_db.map do |r|
                r.update_attribute(column_name, false)
              end
            end

            self.concat(records)
          end
        end
      end
    end
  end
end

#load_method ⇒ Object

Unused method = “default_#resource_column”.to_sym class_variable_set(“@@#method”.to_sym, column_name.freeze) define_singleton_method(method) { class_variable_get(“@@#method”.to_sym) }



15
16
17
18
 
# File 'lib/defaulter/has_default.rb', line 15

def load_method
  @@load_method ||= (Gem::Version.new('4.0.0') >=
    Gem::Version.new(Rails.version)) ? :all : :load
end