Other than self.class.send :method, args...
, of course. I'd like to make a rather complex method available at both the class and instance level without duplicating the code.
UPDATE:
@Jonathan Branam: that was my assumption, but I wanted to make sure nobody else had found a way around. Visibility in Ruby is very different from that in Java. You're also quite right that private
doesn't work on class methods, though this will declare a private class method:
class Foo
class <<self
private
def bar
puts 'bar'
end
end
end
Foo.bar
# => NoMethodError: private method 'bar' called for Foo:Class
Using BasicObject#instance_eval , you can call private method.
It has to be explicitly included on each inherited class, or else the included method will only get called for the parent A . The class_eval block executes within the including class's context, so it's just like opening up the class in your class definition.
private variables and methods can be accessed anywhere from the instance of the class that declares it.
Here is a code snippet to go along with the question. Using "private" in a class definition does not apply to class methods. You need to use "private_class_method" as in the following example.
class Foo
def self.private_bar
# Complex logic goes here
puts "hi"
end
private_class_method :private_bar
class <<self
private
def another_private_bar
puts "bar"
end
end
public
def instance_bar
self.class.private_bar
end
def instance_bar2
self.class.another_private_bar
end
end
f=Foo.new
f=instance_bar # NoMethodError: private method `private_bar' called for Foo:Class
f=instance_bar2 # NoMethodError: private method `another_private_bar' called for Foo:Class
I don't see a way to get around this. The documentation says that you cannot specify the receive of a private method. Also you can only access a private method from the same instance. The class Foo is a different object than a given instance of Foo.
Don't take my answer as final. I'm certainly not an expert, but I wanted to provide a code snippet so that others who attempt to answer will have properly private class methods.
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