ExtensibleAttrAccessor

Allow attr_accessor, attr_reader, attr_writer to accept blocks.

Installation

Add this line to your application's Gemfile:

gem 'extensible_attr_accessor'

And then execute:

$ bundle

Or install it yourself as:

$ gem install extensible_attr_accessor

Usage

attr_xxx can make multiple accessor at one line, but they cannot be easily modified.

With this gem, attr_accessor, attr_reader, attr_writer can have a block, and common modification can be applied to multiple accessors.

Without a block, all metamethods call original ones, so this gem causes no impact for existing code.

Module#attr_reader

When attr_reader is used with a block, the block is called when generated methods are called with one parameter (raw value of corresonding instance variable).

The return values of generated methods are the ones from block.

  #define getters converting to string
  attr_reader(:foo, :bar){|val| val.to_s }

  #shorthand
  attr_reader :foo, :bar, &:to_s

Module#attr_writer

When attr_writer is used with a block, the block is called when generated methods are called with one parameter (the input parameter of setter method).

The return value of the block is stored by the setter.

  #define setters always capitalizing
  attr_writer(:foo, :bar){|val| val.capitalize }

  #shorthand
  attr_writer :foo, :bar, &:capitalize

Module#attr_accessor

Doing above two functionalities in one attr_accessor. The block is called with two arguments, the first one is value, next one is operation mode (:get or :set).

I wonder where this method is useful, but made this for completeness.

Development

After checking out the repo, run bin/setup to install dependencies. Then, 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 to create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

  1. Fork it ( https://github.com/jkr2255/extensible_attr_accessor/fork )
  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 a new Pull Request