Module: DiFtw::Builder

Defined in:
lib/diftw/builder.rb

Overview

Module for building various things, like other modules.

Class Method Summary collapse

Class Method Details

.injector_module(parent_injector, dependencies) ⇒ Module

Builds a new module that, when included in a class, defines instance methods for each dependecy.

Parameters:

  • parent_injector (DiFtw::Injector) —

    The parent injector

  • dependencies (Symbol) —

    All dependency names you want to inject

Returns:

  • (Module) —

    A module with accessor methods defined for each dependency



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# File 'lib/diftw/builder.rb', line 13

def self.injector_module(parent_injector, dependencies)
  Module.new {
    class << self
      attr_accessor :injector, :_diftw_dependencies
    end

    def self.included(base)
      di_mod = self
      base.class_eval do
        # Set the injector for the whole class
        class << self; attr_reader :injector; end
        @injector = di_mod.injector

        # Create a new injector for each instance
        define_method :injector do
          @injector ||= Injector.new(parent: di_mod.injector)
        end

        # Define a method to eager-inject all dependencies
        define_method :inject! do
          di_mod._diftw_dependencies.each do |dep|
            send dep
          end
          nil
        end
      end

      # Define instance accessor methods. Do as a string so we get/set instance variables directly.
      base.class_eval _diftw_dependencies.map { |dep|
        "def #{dep}; @_diftw_#{dep} ||= self.injector[:#{dep}]; end"
      }.join $/
    end

    def self.extended(base)
      di_mod = self
      base.singleton_class.class_eval { include di_mod }
    end
  }.tap { |mod|
    mod.injector = Injector.new(parent: parent_injector)
    mod._diftw_dependencies = dependencies
  }
end