Module: HasHelpers::Attributes::GuardedAttributes

Included in:
UIAttributes, UIAttributes::HTMLAttributes
Defined in:
lib/has_helpers/attributes.rb

Overview

GuardedAttributes provides--and combines!--shortcuts for many common patterns of accessor methods.

Take for example this service accessor. There is a normal writer method which lets the user optionally set service. The reader method should always return either nil or a Service object, which is ensured by calling to_service, the "guard" method.

attr_writer :service
def service
@service && @service.to_service
end

guarded_attr_accessor does all that in one line. guarded_attr_accessor is smart and will convert the object passed in as the guard to a Proc, so you may simply pass in a symbol. There is also an auto_guard option which will generate the Proc based on the attribute name. The following lines are all equivalent:

guarded_attr_accessor :service, guard: -> value { value.to_service }
guarded_attr_accessor :service, guard: :to_service
guarded_attr_accessor :service, auto_guard: true

auto_guard is most convenient when defining multiple attributes.

guarded_attr_accessor :service, :icon, :action, auto_guard: true

The previous example is equivalent to:

guarded_attr_accessor :service, guard: :to_service
guarded_attr_accessor :icon, guard: :to_icon
guarded_attr_accessor :action, guard: :to_action

Defined Under Namespace

Modules: ClassMethods, InstanceMethods

Class Method Summary collapse

Class Method Details

.included(klass) ⇒ Object 



41
42
43
44
45
46
47
48
49
 
# File 'lib/has_helpers/attributes.rb', line 41

def self.included(klass)
  klass.extend(ClassMethods)
  klass.include(InstanceMethods)
  klass.class_eval do
    ClassMethods.instance_methods.each do |method_name|
      private_class_method method_name
    end
  end
end