askrynnikov/normalizr

Attribute normalizer on steroids for Ruby 2.x

Normalizr

The attribute_normalizer replacement.

Synopsis

Attribute normalizer doesn't normalize overloaded methods correctly. Example:

class Phone
  include AttributeNormalizer

  attr_accessor :number
  normalize_attribute :number

  def number=(value)
    @number = value
  end
end

number will never be normalized as expected. Normalizr resolves this problem and doesn't pollute target object namespace.

Magic based on ruby's prepend feature, so it requires 2.0 or higher version.

Installation

Add this line to your application's Gemfile:

gem 'normalizr'

And then execute:

$ bundle

Or install it yourself as:

$ gem install normalizr

Usage

Specify default normalizers:

Normalizr.configure do
  default :strip, :blank
end

Register custom normalizer:

Normalizr.configure do
  add :titleize do |value|
    String === value ? value.titleize : value
  end

  add :truncate do |value, options|
    if String === value
      options.reverse_merge!(length: 30, omission: '...')
      l = options[:length] - options[:omission].mb_chars.length
      chars = value.mb_chars
      (chars.length > options[:length] ? chars[0...l] + options[:omission] : value).to_s
    else
      value
    end
  end

  add :indent do |value, amount = 2|
    if String === value
      value.indent(amount)
    else
      value
    end
  end
end

Add attributes normalization:

class User < ActiveRecord::Base
  normalize :first_name, :last_name, :about # with default normalizers
  normalize :email, with: :downcase

  # you can use default and custom normalizers together
  normalize :middle_name, with: [:default, :titleize]

  # supports `normalize_attribute` and `normalize_attributes` as well
  normalize_attribute :skype

  # array normalization is supported too
  normalize :skills
end

user = User.new(first_name: '', last_name: '', middle_name: 'elizabeth ', skills: [nil, '', ' ruby'])
user.email = "[email protected]"

user.first_name
#=> nil
user.last_name
#=> nil
user.middle_name
#=> "Elizabeth"
user.email
#=> "[email protected]"
user.skills
#=> ["ruby"]

class SMS
  include Normalizr::Concern

  attr_accessor :phone, :message

  normalize :phone, with: :phone
  normalize :message

  def initialize(phone, message)
    self.phone   = phone
    self.message = message
  end
end

sms = SMS.new("[phone]", "It works \n")
sms.phone
#=> "18105550000"
sms.message
#=> "It works"

You can also use if/unless options (they accept a symbol (method name) or proc):

class Book
  include Normalizr::Concerns

  attr_accessor :author, :description, :date

  normalize :author, if: :author_should_be_normalized?
  normalize :description, unless: :description_should_not_be_normalized?

  normalize :author, if: -> { date.today? }
end

Normalize values outside of class:

Normalizr.normalize(value)
Normalizr.normalize(value, :strip, :blank)
Normalizr.normalize(value, :strip, truncate: { length: 20 })

ORMs

Normalizr automatically loads into:

• ActiveRecord
• Mongoid

RSpec matcher

describe User do
  it { should normalize(:name) }
  it { should normalize(:phone).from('[phone]').to('18105550000') }
  it { should normalize(:email).from('[email protected]').to('[email protected]') }
end

Built-in normalizers

• blank
• boolean
• capitalize
• control_chars
• downcase
• phone
• squish
• strip
• upcase
• whitespace

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

Thanks

Special thanks to Michael Deering for original idea.