# CodeBox::CodeAttribute

Lets you define attributes as codes, instead keys (ids). For simple option storage saving a string code is often more simple an conveniant the storing an artificial id-key referencing a special code object.
CodeBox lets you access define codes as strings and access the associated code objects in various ways.



## Installation

Add this line to your application's Gemfile:

    gem 'code-box'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install code-box



## Sample Usages

### Specifying attributes as codes

There are cases you want to store 'named codes' instead artificial keys.
Codes make sense for stable references and better readability of the raw data.

There are several options to specify an attribute as a code:
  1. The code value is used for I18n translation (e.g. nationality_code: 'SUI' -> nationality: 'Switzerland' (when locale is 'en')).
  1. The code value is used to lookup a specific code object that implements `.for_code`.
  1. The code value is a foreign key on a specific ActiveRecord code object.


#### Lookup through I18n

Example

    class Person
      include CodeBox::CodeAttribute

      attr_accessor  :nationality_code

      code_attribute :nationality
    end

The include will create the following methods in Person:

  `#nationality` Will return the nationality text for the value stored in `nationality_code`. For the code 'SUI' the I18n key would look like: `activerecord.values.person.nationality_code.SUI` (Note: The key is build like the standard I18n keys for activerecord classes or attribute by default. Since I dislike the `activerecord` naming and prefer `model` I made this configurable - see below).

  `.translate_nationality_code` Translates a code or an array of codes returning the translated code
  or an array of translated codes. If passing the option `:build => :zip` the method returns an array
  of arrays with translation and code which can be used to build html options.


#### Lookup through code object

Example

    class Person
      include CodeBox::CodeAttribute

      attr_accessor :nationality_code

      code_attribute :nationality, :lookup_type => :lookup
    end

    # Note: Below class is a plain sample implementation. Code objects can be built easier with
    #       'ActsAsCode' include (see below)
    class Code::Nationality
      attr_accessor :code, :name

      def self.for_code(code)
        # return the correct Code::Nationality for the passed code
      end
    end


The include will create the following method in Person:

  `#nationality` Will return the nationality object looked up using the method '.for_code' on the code class.
  Translation then can be done within this class with the first method described above ('acts_as_code' facilitates this as well).



#### Lookup through associated AR Code Object

The code value is interpreted as a foreign key on an associated AR Code object.

    class Person < ActiveRecord::Base
      include CodeBox::CodeAttribute

      code_attribute :nationality, :lookup_type => :associated
    end

    # Note: Below class is a plain sample implementation. Code objects can be built easier with
    #       'ActsAsCode' include (see below)
    class Code::Nationality < ActiveRecord::Base
      # has attribute 'code' of type string
    end

The include and code specification will create the following methods in Person:

  `#nationality` - will return the nationality looked up through AR association on the associated code object - implemented through below AR association:

      belongs_to :nationality,
        :class_name  => 'Codes::Nationality',
        :foreign_key => :nationality_code,
        :primary_key => :code

  Above options can be overwritten in the 'code_attribute' option.



### Defining code classes (acts_as_code)

As describe above code_attributes can reference code objects if the `code_attribute` is of type `:associated` or `:lookup`.

Making an code object `acts_as_code` provides the following features:

  * `&#35;translated_code(locale=I18n.locale, *other_locale_options)
    Translates the code stored in `code`

  * `&#35;translated_code(locale=I18n.locale, *other_locale_options)`
    Translates the code stored in `code`

  * `.translate_code(code, *options)`
    Translates a single code if `code` is a code, an array of codes of `code` is an array.
    If code is an array the option :build => :zip can be used to build a select option capable array (e.g `[['Switzerland', 'SUI'],['Germany', 'GER'],['Denmark', 'DEN']]`)

  * `.for_code(code)
    Answers the code object for the given code (fetched from cache)

  * `.clear_code_cache`
    Clears the cache so its build up on need from all codes from scratch


  __Note:__ The code name can be configures using the `:code_attribute` option.
  `:code_attribute => :iso_code` leads to methods like #translate_iso_code etc.


#### Plain old ruby object codes (:poro)

Assuming we have a simple ruby class with default code attribute 'code' we can defined such a class like

    class Codes::MySpecificCode
      include CodeBox::ActsAsCode

      # Above include cretes the following:
      #
      # attr_accessor :code
      #
      # def initialize(code)
      #  @code = code
      # end
      #
      # def self.all
      #   raise "Sublass responsibility. You should implement '.all' returning all codes"
      # end

      # @return [Array] List if all code objects (instances of this)
      def self.all
        # you need to implement this
      end

    end

Configuration options are:

    :type           => :poro #(default, other :active_record)
    :code_attribute => :code #(default) or any other name as symbol



#### ActiveRecod code objects (:active_record)

Assuming we have an ActiveRecod code class with `code_attribute :code` we can defined such a class like

    class Codes::MySpecificCode < ActiveRecord::Base
      include CodeBox::ActsAsCode[:type => :active_record]

      # Above include cretes the following:
      #
      # validates_presence_of   :code
      # validates_uniqueness_of :code
      #
      # default_scope order('code')

    end

Configuration options are:

    :type                      => :active_record # other :poro(default)
    :code_attribute            => :code          # (default) or any other name as symbol
    :polymorphic               => false          # (default). If `true` the uniqueness validation is scope by the attribute `type`
    :uniqueness_case_sensitive => true           # (default). If `false` the the uniqueness validation is case insensitive
    :position_attr             => :position      # If present, the order when fetching the codes is done with this expression (default scope - means - if you want to omit the order used `unscoped` on any AR operation).



### Examples
  TO BE DONE…

## Contributing

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