Attribute Cartographer

DESCRIPTION

Attribute Cartographer allows you to map an attributes hash into similarly or differently named methods, using an optional lambda to map the values as well.

INSTALL

Add attribute-cartographer to your Gemfile

gem 'attribute-cartographer'

Then run:

$ bundle

USAGE

class Mapper
  include AttributeCartographer

  # one-way mapping
  map "UnchangedKey"                                                              # map a single key, value untouched
  map %w{ UnchangedKey1 UnchangedKey2 }                                           # same as above, but for multiple in a single statement

  map "SameKeyNewValue", ->(v) { v.downcase }                                     # maps the key, using the lambda for the value
  map %w{ SameKeyNewValue1 SameKeyNewValue2 }, ->(v) { v.upcase }                 # same as above, but for multiple in a single statement

  map "OldKey", "new_key", ->(v) { v.downcase }                                   # maps the left key to the right key, using the lambda for the value
  map "DowncasedKeyAndValue", ->(k,v) { [k.downcase, v.downcase] }                # maps the key and value using the lambda for both
  map %w{ NewKeyAndValue1 NewKeyAndValue2 }, ->(k,v) { [k.downcase, v.downcase] } # same as the example above, but for multiple in a single statement

  # two-way mapping
  map "AnotherOldKey", "another_new_key"                                          # map the left key to the right key and vice-versa, value untouched
  map "ThisKey", "to_this_key", ->(v) { v.downcase }, ->(v) { v.upcase }          # map the left key to the right key with the first lambda,
                                                                                  # and the right key to the left key with the second lambda

end

Mapper.new("UnchangedKey" => "UnchangedValue", "OldKey" => "OldValue")            # etc. 

For each mapping defined, an entry in mapped_attributes will be made using the
logic defined in the mapping. You also get another method, original_attributes,
that retains the entire hash that was passed to #initialize, whether the keys
were mapped or not.

REQUIREMENTS

  • Ruby 1.9.x

LICENSE

MIT