cheap_advice¶ ↑

Add/remove advice around, before or after methods in Ruby.

class MyClass
  def foo
    42
  end
end

class MyOtherClass
  def bar
    43
  end
end

a = MyClass.new
b = MyOtherClass.new

trace_advice = CheapAdvice.new(:around) do | ar, body |
  ar.advice[:log].puts "#{Time.now.iso8601(6)} #{ar.rcvr.class} #{ar.method} #{ar.rcvr.object_id}"
  body.call
  ar.advice[:log].puts "#{Time.now.iso8601(6)} #{ar.rcvr.class} #{ar.method} #{ar.rcvr.object_id} => #{ar.result.inspect}"    
end
trace_advice[:log] = File.open("trace.log", "a+")
trace_advice.advise!(MyClass, :foo)
trace_advice.advise!(MyOtherClass, :bar)

a.foo
b.bar

trace_advice.disable!

a.foo
b.bar

trace.log will contain something like:

2011-01-17T16:33:27.882122-06:00 MyClass foo 69872883178280
2011-01-17T16:33:27.882262-06:00 MyClass foo 69872883178280 => 42
2011-01-17T16:33:27.882319-06:00 MyOtherClass bar 69872883178200
2011-01-17T16:33:27.882367-06:00 MyOtherClass bar 69872883178200 => 43

• CheapAdvice::Configuration provides a generic mechanism to configure multiple advices on different methods.

• CheapAdvice::Trace provides an example advice factory for generic method tracing/logging. See examples/ex02.rb.

• Rails-type autoloading can confuse CheapAdvice.

• kurtstephens.com/pub/cheap_advice.slides/index.html

• Check out the latest master to make sure the feature hasn’t been implemented or the bug hasn’t been fixed yet

• Check out the issue tracker to make sure someone already hasn’t requested it and/or contributed it

• Fork the project

• Start a feature/bugfix branch

• Commit and push until you are happy with your contribution

• Make sure to add tests for it. This is important so I don’t break it in a future version unintentionally.

• Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright © 2008-2011 Kurt Stephens. See LICENSE.txt for further details.