I want to dynamically create instance method of child class through class method of parent class.
class Foo
def self.add_fizz_method &body
# ??? (This is line 3)
end
end
class Bar < Foo
end
Bar.new.fizz #=> nil
class Bar
add_fizz_method do
p "i like turtles"
end
end
Bar.new.fizz #=> "i like turtles"
What to write on line #3?
use define_method like this:
class Foo
def self.add_fizz_method &block
define_method 'fizz', &block
end
end
class Bar < Foo; end
begin
Bar.new.fizz
rescue NoMethodError
puts 'method undefined'
end
Bar.add_fizz_method do
p 'i like turtles'
end
Bar.new.fizz
output:
method undefined
"i like turtles"
p self.class below p 'i like turtles'. self already is an instance of Bar.nil instead of throwing a NoMethodError before having called add_fizz_method, you can declare an empty fizz method in the Foo class.define_method 'fizz', do &block.call end previously. tyvm. got what I needed and learned a thing.define_method 'fizz' do
puts 'fizz'
end
...or accepting a block
define_method 'fizz', &block
