In the current app i’m working on, I wanted to store multiple values in a single column. I know, violation of the first normal form.. blah blah blah. Save it.

Anyway, I wanted to have a multiple select box that would easily allow me to Manage and update the attributes of the model. Here is my solution.

Create the database table


create_table :tshirt, :force => true do |t|
t.column :available_colors, :string
t.column :available_sizes, :string
end

Create the Model


class Tshirt < ActiveRecord::Base
serialize :available_colors, Array
serialize :available_sizes, Array
end

Create the YAML Options Hash

I use an options.yml file in the config directory to setup the options for the object. A containing hash is created using the name of the object, and then the sub-hashes match the name of the column.

./config/options.yml


tshirt:
available_colors:
1: Red
2: Blue
3: Green
available_sizes:
1: Small
2: Medium
3: Large

Load the Options File into the App

In your environment.rb file you have to load the YAML parser and then parse the options.yml file:




require ‘yaml’
OPTIONS = YAML::load(File.open(”#{RAILS_ROOT}/config/options.yml”))

The Select Box

This is the hard part.


module ActionView
module Helpers
module FormOptionsHelper
  include ERB::Util
    def serialized_multiple_select(object, method, choices = {}, options = {}, html_options = {})
      html = []
      html << “” 
      return html
    end
end
end
end

Add the select box to your form

And this is the easy part:






<%= serialized_multiple_select ‘tshirt’, ‘available_colors’ %>





<%= serialized_multiple_select ‘tshirt’, ‘available_sizes’ %>

I am pretty sure there are better way to do this, but this one worked for me.

Also, my serialized_multiple_select has options that it doesn’t even use. I should really use them. Please offer feedback if you have any. :)

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