ConfigLeaf
ConfigLeaf allows an object to be configured using a terse syntax like Object#instance_eval, while not exposing the internals (protected/private methods and ivars) of the object!
If the user doesn't like to use this ConfigLeaf wrapping, then they can just use normal #tap syntax by requesting a block parameter.
Installation
Add this line to your application's Gemfile:
gem 'config_leaf'And then execute:
$ bundleOr install it yourself as:
$ gem install config_leafUsage
ConfigLeaf can be used directly by the end-user after an object has been created, but it more likely used by those wanting to allow block setting of config after their object has been instantiated:
require 'config_leaf'
class Cheese
attr_accessor :value, :list
def initialize(&block)
# Set defaults.
@value = 0
@list = []
# Allow the user access via ConfigLeaf syntax.
ConfigLeaf.wrap self, &block if block_given?
end
def reverse!
@list.reverse!
end
protected
def explode!
DeathStar.instance.boom!
end
end
# User uses the ConfigLeaf block syntax.
object1 = Cheese.new do
list [1, 2, 3] # Calls object.list = [1, 2, 3]
list << 4 # Calls object.list << 4
value 5 # Calls object.value = 5
value list.size # Calls object.value = object.list.size
reverse! # Calls object.reverse!
## @value = 99 # Would set @value on the wrapper, not in the wrapped object, so raises an exception.
## explode! # Not allowed because it is protected (raises an exception).
end
# User chooses to not use ConfigLeaf block syntax by requesting a block parameter.
object2 = Cheese.new do |c|
c.list = [1, 2, 3]
c.list << 4
c.value = 5
c.value = c.list.size
c.reverse!
end
p object1 #=> #<Cheese:0x4340658 @value=4, @list=[4, 3, 2, 1]>
p object2 #=> #<Cheese:0x45d2b58 @value=4, @list=[4, 3, 2, 1]>Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature) - Commit your changes (
git commit -am 'Added some feature') - Push to the branch (
git push origin my-new-feature) - Create new Pull Request