Question

I’ve been trying to come up with a way to declare array constants in a class, and then present the members of the arrays as grouped options in a select control. The reason I am using array constants is because I do not want the options being backed by a database model.

This can be done in the basic sense rather easily using the grouped_collection_select view helper. What is not so straightforward is making this localizable, while keeping the original array entries in the background. In other words, I want to display the options in whatever locale, but I want the form to submit the original array values.

Anyway, I’ve come up with a solution, but it seems overly complex. My question is: is there a better way? Is a complex solution required, or have I overlooked a much easier solution?

I’ll explain my solution using a contrived example. Let’s start with my model class:

class CharacterDefinition < ActiveRecord::Base
  HOBBITS = %w[bilbo frodo sam merry pippin]
  DWARVES = %w[gimli gloin oin thorin]
  @@TYPES = nil

  def CharacterDefinition.TYPES
    if @@TYPES.nil?
      hobbits = TranslatableString.new('hobbits', 'character_definition')
      dwarves = TranslatableString.new('dwarves', 'character_definition')
      @@TYPES = [
        { hobbits => HOBBITS.map {|c| TranslatableString.new(c, 'character_definition')} },
        { dwarves => DWARVES.map {|c| TranslatableString.new(c, 'character_definition')} }
      ]
    end
    @@TYPES
  end  
end

The TranslatableString class does the translation:

class TranslatableString
  def initialize(string, scope = nil)
    @string = string;
    @scope = scope
  end

  def to_s
    @string
  end

  def translate
    I18n.t @string, :scope => @scope, :default => @string
  end
end

And the view erb statement look like:

<%= f.grouped_collection_select :character_type, CharacterDefinition.TYPES, 'values[0]', 'keys[0].translate', :to_s, :translate %>

With the following yml:

en:
  character_definition:
    hobbits: Hobbits of the Shire
    bilbo: Bilbo Baggins
    frodo: Frodo Baggins
    sam: Samwise Gamgee
    merry: Meriadoc Brandybuck
    pippin: Peregrin Took
    dwarves: Durin's Folk
    gimli: Gimli, son of Glóin
    gloin: Glóin, son of Gróin
    oin: Óin, son of Gróin
    thorin: Thorin Oakenshield, son of Thráin

The result is:

So, have I come up with a reasonable solution? Or have I gone way off the rails?

Thanks!

Answer 1

From the resounding silence my question received in response, I am guessing that there is not a better way. Anyway, the approach works and I am sticking to it until I discover something better.