Module Innate::StateAccessor
In: lib/innate/state/accessor.rb

Simplify accessing Thread.current variables.

Example:

  class Foo
    include Innate::StateAccessor
    state_accessor :session

    def calculate
      session[:num1] + session[:num2]
    end
  end

Foo#calculate can now be called from anywhere in your application and it will have direct access to the session in the current request/response cycle in a thread-safe way without the need to explicitly pass the session along.

Methods

Public Class methods

Iterate over the names and yield accordingly. names are either objects responding to to_sym or hashes.

It‘s only used within this module to make the code readable.

Used below.

Public Instance methods

Combined state_writer and state_reader. initializer is a block that may be given and its result will be the new value in case the method created by state_reader was never called before and the value wasn‘t set before.

Example:

  state_accessor(:session)
  state_accessor(:user){ session[:user] }

Reader accessor for Thread.current[key]

Example:

  class Foo
    include Innate::StateAccessor
    state_reader(:session)
    state_reader(:random){ rand(100_000) }

    def calculate
      val1 = session[:num1] + session[:num2] + random
      val2 = session[:num1] + session[:num2] + random
      val1 == val2 # => true
    end
  end

NOTE:

  If given +initializer+, there will be some performance impact since we
  cannot use class_eval and have to use define_method instead, we also
  have to check every time whether the initializer was executed already.

  In 1.8.x the overhead of define_method is 3x that of class_eval/def
  In 1.9.1 the overhead of define_method is 1.5x that of class_eval/def

  This may only be an issue for readers that are called a lot of times.

Writer accessor to Thread.current[key]=

  Example:

  class Foo
    include Innate::StateAccessor
    state_writer(:result)

    def calculate
      self.result = 42
    end
  end

  class Bar
    include Innate::StateAccessor
    state_reader(:result)

    def calculcate
      result * result
    end
  end

  Foo.new.calculate # => 42
  Bar.new.calculate # => 1764

[Validate]