Module: Hexx::Services::DependenciesDSL

Included in:
Base
Defined in:
lib/hexx-services/dependencies_dsl.rb

Overview

The module provides features to declare dependencies of service objects from other service objects.

Examples:

class MyService
  extend DSL::DependenciesDSL
  depends_on :get_item, GetItem
end

service = MyService.new
service.get_item             # => GetItem
service.get_item = FindItem  # => FindItem
service.get_item = nil       # => GetItem

Instance Method Summary collapse

Instance Method Details

#depends_on(name, default = nil) ⇒ Symbol

Declare the dependency with a default value

Parameters:

  • name (Symbol, String) —

    The name of the dependency

  • default (Class) (defaults to: nil) —

    The default implementation for the dependency

Returns:

  • (Symbol) —

    the name of the dependency

Raises:

  • (TypeError) —

    if default is set to class that is not a service



32
33
34
35
36
37
38
39
40
41
42
43
 
# File 'lib/hexx-services/dependencies_dsl.rb', line 32

def depends_on(name, default = nil)
  if default.nil?
    attr_accessor(name)
  elsif default.kind_of_service_class?
    define_method(name) { instance_variable_get(:"@#{ name }") || default }
    attr_writer name
  else
    fail TypeError.new "The #{ default.inspect } is not a service"
  end

  self
end