method mixin?

[Cnm Cnm]

Just wonder is there any way to inject a bunch of code into an instance
method, just like how a module can be used as a mixin to a class?

 

[Robert Klemme]

Just wonder is there any way to inject a bunch of code into an instance
method, just like how a module can be used as a mixin to a class?

One thing you can do is alias the original and use it.

class Foo
def bar; puts 123; end
end

f = Foo.new
f.bar

class Foo
alias _bar bar

def bar
puts "before"
x = _bar
puts "after"
x
end
end

f.bar

I once did some meta programming to nicely declare before and after code
but that code was never production ready. IIRC others did similar things.

Kind regards

robert