extend_method
Dry and simple gem for method overriding in non-inheritance contexts.
Status
This implementation is a release candidate.
Please report issues in the issue tracker. Pull requests are welcome.
License
The extend_method library is open-source software licensed under the BSD 3-clause license. The full text of the license may be found in the LICENSE file.
Credits
This library is written and maintained by Eric Bollens.
Usage
Require the gem:
require 'extend_method'
The extend_method
class method can then be included as:
class Example
class << self
include ExtendMethod
end
end
A motivating example showing some of the major features:
module Base
def set val
@val = val
end
def get
@val
end
end
class Extended
include Base
class << self
include ExtendMethod
end
extend_method :set do |val|
parent_method "#{val}!"
end
extend_method :get do
"foo#{parent_method}"
end
extend_method :other do
if has_parent_method?
parent_method
else
# do something else
end
end
end
example = new Extended
example.set 'bar'
assert 'foobar!' == example.get
The extend_method
class method takes a symbol for the method name and a block that extends the method, exposing the previous version of the method as parent_method
:
class Example
def basic_example
# ..
end
extend_method :basic_example do
# ..
val = parent_method
# ..
end
end
To determine if a parent method exists, use the has_parent_method?
method:
class Example
extend_method :optional_parent_method_example do |*args|
# ..
parent_method(*args) if has_parent_method?
# ..
end
end
The block accepts arguments for what's passed to the method:
class Example
extend_method :argument_example do |val|
"foo#{parent_method val}"
end
end