Note Due to Google Code is shutting down this project has moved to https://github.com/cheind/rcapture

Introduction

RCapture is a Ruby library that allows placing hooks on methods using a convenient interface. RCapture is a versatile tool supporting different programming paradigms such as aspect-oriented programming. It is also referred to as the 'ultimate monkey patch' library.

RCapture offers the following core features

• Capturing of instance and class methods of individual objects or entire population of objects.
• Capturing pre or post method invocation.
• Multiple capturings per method.
• Modify method arguments and return values.
• Filter method calls.
• Developed with multithreaded environments in mind

Here is what Gregg and Nate of Ruby5 have to say on RCapture:

(...) it does provide a very powerful programming tool. You can basically have hooks which manipulate the data coming into a method or going out from, at will. It’s like the ultimate monkey patch.

Example

``` require 'rcapture'

class Array # RCapture::Interceptable is a module mixin that provides capturing capatibilities. include RCapture::Interceptable end

Array.capture_post :methods => [:<<, :push] do |cs| puts "#{cs.args.first} was inserted to array #{cs.sender}" end

[] << 1 << 2 [].push 3

=> 1 was inserted to array [1]

=> 2 was inserted to array [1, 2]

=> 3 was inserted to array [3]

```

More examples can be found here or here.

Installation

You can install RCapture using RubyGems by invoking ```

gem install rcapture Successfully installed rcapture-1.0.4 in case that fails, you might want to update your gem system before installing RCapture gem update --system ```

Alternatively download the gem from the download section and install locally ```

gem install rcapture-1.0.4.gem ```

Documentation

An up-to-date RCapture documentation can be found here.

Christoph has written an introductionary article to RCapture at his blog.

Make sure you read the HowTo page.

Help Wanted!

Due to the limited amount of time I can spend on this project, I'm actively searching for people joining the project. If you'd like to contribute, get in touch now!