Module: Enum::Helpers::EnumAttribute

Includes:
EnumGenerator
Included in:
EnumColumn, Module
Defined in:
lib/enum/helpers/enum_attribute.rb

Instance Method Summary collapse

Methods included from EnumGenerator

#yinum

Instance Method Details

#attr_yinum(attr, name_or_enum, options = {}, hash = nil) ⇒ Object Also known as: attr_enum

Bind an attribute to an enum by:

Generating attribute reader and writer to convert to EnumValue.
If :qualifier => true, generates questioning methods for every name in the enum.

If given a enum name (a symbol) and hash, also creates the enum.



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# File 'lib/enum/helpers/enum_attribute.rb', line 10

def attr_yinum(attr, name_or_enum, options = {}, hash = nil)
  # the first hash is either options or the hash if the options are missing
  hash, options = options, {} unless name_or_enum.is_a?(Enum) or hash
  # generating or getting the enum
  if name_or_enum.is_a?(Enum)
    e = name_or_enum
  else
    # generating the enum if the hash is not empty
    yinum name_or_enum, hash if hash.any?
    e = const_get(name_or_enum)
  end
  # attribute reader
  reader, reader_without_enum = attr, :"#{attr}_without_enum"
  begin
    alias_method reader_without_enum, reader
  rescue NameError # reader does not exist
    no_reader = true
  end
  define_method(reader) do
    v = no_reader ? super() : send(reader_without_enum)
    (ev = e.get(v)).nil? ? Enum::EnumValue.new(e, v) : ev
  end
  # attribute writer
  writer, writer_without_enum = :"#{attr}=", :"#{attr}_without_enum="
  begin
    alias_method writer_without_enum, writer
  rescue NameError # writer does not exist
    no_writer = true
  end
  define_method(writer) do |v|
    v = case
          when v.enum_value? then v.value
          # might be received from forms
          when v.nil?, v == "" then v
          else e[v].value
        end
    no_writer ? super(v) : send(writer_without_enum, v)
  end

  if options[:qualifier]
    # generating scopes and questioning methods
    e.by_name.each do |n, ev|
      define_method("#{n}?") { send(attr) == ev }
    end
  end

  e
end