class Hashie::Dash

API for defining properties as well as per-property defaults.
It is preferrable to a Struct because of the in-class
resources than something like a DataMapper resource.
lightweight data object that needs even fewer options and
Dashes are useful when you need to create a very simple
optional defaults) and only those keys may be set or read.
that has a set of defined keys that are accessible (with
A Dash is a ‘defined’ or ‘discrete’ Hash, that is, a Hash

def self.defaults

The default values that have been set for this Dash

def self.defaults
  @defaults
end

def self.properties

properties on this Dash.
Get a String array of the currently defined

def self.properties
  @properties.collect{|p| p.to_s}
end

def self.property(property_name, options = {})

Dash.
to be returned before a value is set on the property in a new
* :default - Specify a default value for this property,

as follows:
Defines a property on the Dash. Options are

def self.property(property_name, options = {})
  property_name = property_name.to_sym
  
  (@properties ||= []) << property_name
  (@defaults ||= {})[property_name] = options.delete(:default)
  
  class_eval <<-RUBY
    def #{property_name}
      self['#{property_name}']
    end
    
    def #{property_name}=(val)
      self['#{property_name}'] = val
    end
  RUBY
end

def self.property?(prop)

defined.
Check to see if the specified property has already been

def self.property?(prop)
  properties.include?(prop.to_s)
end

def [](property_name)

property's default value if it hasn't been set).
Retrieve a value from the Dash (will return the

def [](property_name)
  super || self.class.defaults[property_name.to_sym]
end

def []=(property, value)

on pre-existing properties.
Set a value on the Dash in a Hash-like way. Only works

def []=(property, value)
  if self.class.property?(property)
    super
  else
    raise NoMethodError, 'You may only set pre-defined properties.'
  end
end