Module: SknUtils::Configurable

Defined in:
lib/skn_utils/configurable.rb

Overview

For making an arbitrary class configurable and then specifying those configuration values using a clean and simple DSL that also lets us reference one configuration attribute from another

Inside Target component

class MyApp

include SknUtils::Configurable.with(:app_id, :title, :cookie_name) # or {root_enable: false})
# ... default=true for root|env|logger

end

Inside Initializer

MyApp.configure do

app_id "my_app"
title "My App"
cookie_name { "#{app_id}_session" }

end

During Definition

class MyApp

include SknUtils::Configurable.with(:app_id, :title, :cookie_name, {root_enable: true})
# ...
configure do
  app_id "my_app"
  title "My App"
  cookie_name { "#{app_id}_session" }
end

self.logger = Logger.new
self.env = ENV.fetch('RACK_ENV', 'development')
self.root = Dir.pwd

end

Usage:

MyApp.config.app_id # ==> “my_app” MyApp.logger # ==> <Logger.class> MyApp.env.test? # ==> true

############### Syntax ############### Main Class Attrs

  • root = application rood directory as Pathname

  • env = string value from RACK_ENV

  • logger = Assiigned Logger instance

#with(*user_attrs, enable_root: true|false) - defaults to enable of Main Class Attrs ## User-Defined Attrs MyThing.with(:name1, :name2, …)

##

Class Method Summary collapse

Class Method Details

.with(*attrs, **options) ⇒ Object 



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# File 'lib/skn_utils/configurable.rb', line 67

def self.with(*attrs, **options)
  _not_provided = Object.new
  _app_main = options.empty? || options.values.any?{|v| v == true}

  # Define the config class/module methods
  config_class = Class.new do
    # add hash notation
    define_method :[] do |attr|
      instance_variable_get("@#{attr}")
    end
    define_method :[]= do |attr, val|
      instance_variable_set("@#{attr}", val)
    end

    attrs.each do |attr|
      define_method attr do |value = _not_provided, &block|
        if value === _not_provided && block.nil?
          result = instance_variable_get("@#{attr}")
          result.is_a?(Proc) ? instance_eval(&result) : result
        else
          instance_variable_set("@#{attr}", block || value)
        end
      end
    end

    attr_writer *attrs
  end

  # Define the runtime access methods
  class_methods = Module.new do
    define_method :config do
      @__config ||= config_class.new
    end
    def configure(&block)
      config.instance_eval(&block)
    end
    if _app_main
      # Enable Rails<Like>.env and Rails.logger like feature:
      # - MyClass.env.production? or MyClass.logger or MyClass.root
      def env
        @__env ||= ::SknUtils::EnvStringHandler.new( ENV.fetch('RACK_ENV', 'development') )
      end
      def env=(str)
        @__env = ::SknUtils::EnvStringHandler.new( str || ENV.fetch('RACK_ENV', 'development') )
      end
      def root
        @__root ||= ::SknUtils::EnvStringHandler.new( Dir.pwd )
      end
      def root=(path)
        @__root = ::SknUtils::EnvStringHandler.new( path || Dir.pwd )
      end
      def logger
        @__logger ||= 'No Logger Assigned.'
      end
      def logger=(obj)
        @__logger = obj
      end
    end
  end

  # Apply the custom configuration
  Module.new do
    singleton_class.send :define_method, :included do |host_class|
      host_class.extend class_methods
    end
  end

end