Wrapit

Wrapit allows you to easily define attributes in a class that should be wrapped, or wrap attributes that have already been defined. The wrapping logic comes from the wrapped gem.

Installation

Add this line to your application's Gemfile:

gem 'wrapit'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install wrapit

Usage

attr_wrappable

So lets say we want to create some setters and getters for a class that come all wrapped and ready to go.

class Foo
  include Wrapit::AttrWrappable

  attr_wrappable :test_attr
end

foo = Foo.new

foo.test_attr = "bar"
foo.test_attr => #<Present:0x0000010ad6fc80 @value="bar">
foo.test_attr.unwrap => "bar"

foo.test_attr = nil
foo.test_attr => #<Blank:0x0000010d3064f8>
foo.test_attr.unwrap => IndexError: Blank has no value
foo.test_attr.unwrap_or("bar") => "bar"

In addition to wrapping up the attribute readers, attr_wrappable creates _naked attribute writers:

foo.test_attr_naked => nil
foo.test_attr_naked = "bar"
foo.test_attr_naked => "bar"

# test_attr= is just an alias to test_attr_naked=
foo.test_attr = "foo"
foo.test_attr_naked = "foo"

method_wrappable

Now lets say you have a method you have inherited from a superclass you want to wrap.

class Foo
  def test_method
    "bar"
  end
end

class Bar < Foo
  include Wrapit::MethodWrappable

  method_wrappable :test_method
end

bar = Bar.new

bar.test_method => #<Present:0x0000010ad6fc80 @value="bar">
bar.test_method.unwrap => "bar"
bar.test_method_naked => "bar"

And that's it!

Further Reading

For more info on what you can do with a wrapped value have a look at the wrapped gem.

Limitations

At the moment method_wrappable is only usable on methods defined in a superclass and that take no arguments.

TODO

1. Add option to attr_wrappable to skip creating attribute writers.
2. Make method_wrappable work with methods that take arguments.
3. Look into method_wrappable working better in scenarios where we want to wrap a dynamic method. ie. ActiveRecord attributes.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request