This library provides three different ways to delegate method calls to an object. The easiest to use is SimpleDelegator. Pass an object to the constructor and all methods supported by the object will be delegated. This object can be changed later.
Going a step further, the top level DelegateClass method allows you to easily setup delegation through class inheritance. This is considerably more flexible and thus probably the most common use for this library.
Finally, if you need full control over the delegation scheme, you can inherit from the abstract class Delegator and customize as needed. (If you find yourself needing this control, have a look at Forwardable which is also in the standard library. It may suit your needs better.)
Add this line to your application's Gemfile:
gem 'delegate'
And then execute:
$ bundle
Or install it yourself as:
$ gem install delegate
SimpleDelegator's implementation serves as a nice example of the use of Delegator:
class SimpleDelegator < Delegator
def __getobj__
@delegate_sd_obj # return object we are delegating to, required
end
def __setobj__(obj)
@delegate_sd_obj = obj # change delegation object,
# a feature we're providing
end
end
After checking out the repo, run bin/setup
to install dependencies. Then, run rake test
to run the tests. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and push the .gem
file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/delegate.