HasPrivateAttributes 🔒

This Ruby gem provides a simple and elegant way to define private attributes in your classes. It allows you to create static, lazy-evaluated, and argument-based private attributes with automatic caching and freezing of the returned values, all in a thread-safe manner. It works for both instance methods and class methods.

Features 🌟

Static Attributes: Define private attributes with a fixed, immutable value.
Lazy Attributes: Define private attributes that are lazily evaluated and cached.
Argument-based Attributes: Define private attributes that depend on arguments and cache the results.
Inheritance: Private attributes can be inherited from parent classes.
Freezing: All returned values are automatically deep-frozen to prevent modification.
Thread Safety: All operations are thread-safe, allowing for use in multi-threaded environments.
Class Method Support: Private attributes can be used in both instance and class methods.

Installation 📥

Add this line to your application's Gemfile:

gem 'has_private_attributes'

And then execute:

bundle install

Usage 🚀

Here's a simple example of how to use the HasPrivateAttributes gem with both instance and class methods:

class MyClass
  include HasPrivateAttributes

  # definition of private attributes

  private_attribute :static_servers, [
    { ip: '1.1.1.1', location: 'US' },
    { ip: '8.8.8.8', location: 'US' }
  ]

  private_attribute :lazy_servers do
    [
      { ip: '2.2.2.2', location: 'EU' },
      { ip: '3.3.3.3', location: 'EU' }
    ]
  end

  private_attribute :servers_by_region do |region|
    case region
    when 'us'
      [
        { ip: '1.1.1.1', location: 'US' },
        { ip: '8.8.8.8', location: 'US' }
      ]
    when 'eu'
      [
        { ip: '2.2.2.2', location: 'EU' }
      ]
    end
  end

  # usage of private attributes in instance methods

  def get_static_servers
    static_servers
  end

  def get_lazy_servers
    lazy_servers
  end

  def get_servers_by_region(region)
    servers_by_region(region)
  end

  # usage of private attributes in class methods

  def self.get_static_servers
    static_servers
  end

  def self.get_lazy_servers
    lazy_servers
  end

  def self.get_servers_by_region(region)
    servers_by_region(region)
  end
end

instance = MyClass.new

puts instance.get_static_servers
# Output:
# [
#   { ip: '1.1.1.1', location: 'US' },
#   { ip: '8.8.8.8', location: 'US' }
# ]

puts MyClass.get_lazy_servers
# Output:
# [
#   { ip: '2.2.2.2', location: 'EU' },
#   { ip: '3.3.3.3', location: 'EU' }
# ]

puts MyClass.get_servers_by_region('us')
# Output:
# [
#   { ip: '1.1.1.1', location: 'US' },
#   { ip: '8.8.8.8', location: 'US' }
# ]

Examples 💡

Here are some more examples of using the HasPrivateAttributes gem:

Static Attributes 🗄️

instance.get_static_servers # => [{ ip: '1.1.1.1', location: 'US' }, { ip: '8.8.8.8', location: 'US' }]
instance.get_static_servers.frozen? # => true
MyClass.get_static_servers # => [{ ip: '1.1.1.1', location: 'US' }, { ip: '8.8.8.8', location: 'US' }]

Lazy Attributes 🐢

instance.get_lazy_servers # => [{ ip: '2.2.2.2', location: 'EU' }, { ip: '3.3.3.3', location: 'EU' }]
instance.get_lazy_servers.object_id # => 12345678
instance.get_lazy_servers.object_id # => 12345678 (same object)
MyClass.get_lazy_servers # => [{ ip: '2.2.2.2', location: 'EU' }, { ip: '3.3.3.3', location: 'EU' }]

Argument-based Attributes 🔍

instance.get_servers_by_region('us') # => [{ ip: '1.1.1.1', location: 'US' }, { ip: '8.8.8.8', location: 'US' }]
instance.get_servers_by_region('eu') # => [{ ip: '2.2.2.2', location: 'EU' }]
MyClass.get_servers_by_region('us') # => [{ ip: '1.1.1.1', location: 'US' }, { ip: '8.8.8.8', location: 'US' }]

Class Methods 🏫

class Configuration
  include HasPrivateAttributes

  private_attribute :default_settings do
    {
      timeout: 30,
      retries: 3,
      log_level: :info
    }
  end

  def self.timeout
    default_settings[:timeout]
  end

  def self.retries
    default_settings[:retries]
  end
end

Configuration.timeout # => 30
Configuration.retries # => 3

Thread Safety 🔒

All operations in HasPrivateAttributes are thread-safe. This means you can safely use private attributes in multi-threaded environments without worrying about race conditions or data inconsistencies. The gem uses Ruby's Monitor and Mutex classes to ensure proper synchronization.

For example, you can safely access private attributes from multiple threads:

threads = []
10.times do
  threads << Thread.new do
    puts MyClass.get_lazy_servers
  end
end
threads.each(&:join)

This will safely initialize and return the lazy servers, even if multiple threads try to access it simultaneously.

Contributing 🤝

Bug reports and pull requests are welcome on GitHub at https://github.com/sebyx07/has_private_attributes. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License 📄

The gem is available as open source under the terms of the MIT License.

Code of Conduct 🤵

Everyone interacting in the HasPrivateAttributes project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.