[Rails] Looking for a way to set a variable when doing Model.new

Indeed.

And maybe better to not mess with the `def initialize`, but use the
`after_initialize` function that is provided by Rails. I did it like this.


../lib/uuid_helper.rb

require 'uuidtools'

module UUIDHelper
extend ActiveSupport::Concern

included do
after_initialize :set_uuid
def set_uuid
unless uuid # Note 1 below
self.uuid = UUIDTools::UUID.random_create.to_s
end
end
end
end

../app/model/person.rb

class Person < ActiveRecord::Base

# UUID
include UUIDHelper
...
end

Note 1:
Be careful, it is a little tricky to _only_ set the value of the uuid
when it is not yet present, otherwise reading back the value
from the database will build a new instance of Person with a
new random uuid. The code above is well tested and works.

Maybe you will also need to add ../lib to your default load path.
In config/application.rb

# Custom directories with classes and modules you want to be
autoloadable.
config.autoload_paths += %W(#{config.root}/lib)
config.autoload_paths += Dir["#{config.root}/lib/**/"]


HTH,

Peter

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Peter Vandenabeele
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