Method: Chef::Resource.build_from_file

Defined in:

lib/chef/resource.rb

.build_from_file(cookbook_name, filename) ⇒ Object

# File 'lib/chef/resource.rb', line 460

def build_from_file(cookbook_name, filename)
  rname = filename_to_qualified_string(cookbook_name, filename)

  # Add log entry if we override an existing light-weight resource.
  class_name = convert_to_class_name(rname)
  overriding = Chef::Resource.const_defined?(class_name)
  Chef::Log.info("#{class_name} light-weight resource already initialized -- overriding!") if overriding
    
  new_resource_class = Class.new self do |cls|
    
    # default initialize method that ensures that when initialize is finally
    # wrapped (see below), super is called in the event that the resource
    # definer does not implement initialize
    def initialize(name, run_context)
      super(name, run_context)
    end
    
    @actions_to_create = []
    
    class << cls
      include Chef::Mixin::FromFile
      
      def actions_to_create
        @actions_to_create
      end
      
      define_method(:actions) do |*action_names|
        actions_to_create.push(*action_names)
      end
    end
    
    # load resource definition from file
    cls.class_from_file(filename)
    
    # create a new constructor that wraps the old one and adds the actions
    # specified in the DSL
    old_init = instance_method(:initialize)

    define_method(:initialize) do |name, *optional_args|
      args_run_context = optional_args.shift
      @resource_name = rname.to_sym
      old_init.bind(self).call(name, args_run_context)
      allowed_actions.push(self.class.actions_to_create).flatten!
    end
  end
  
  # register new class as a Chef::Resource
  class_name = convert_to_class_name(rname)
  Chef::Resource.const_set(class_name, new_resource_class)
  Chef::Log.debug("Loaded contents of #{filename} into a resource named #{rname} defined in Chef::Resource::#{class_name}")
  
  new_resource_class
end