BluePrint

The behavior switching framework. inspired by DCI.

Requirements

Ruby >= 2.0.0
- Tested ruby version:
- 2.0.0
- 2.1.0
- 2.1.1
- head

Installation

Add this line to your application's Gemfile:

gem 'blue_print', '~> 1.3.0'

Usage

Integration

BluePrint provides some integrations. Now supported libraries:

Rails Generators

BluePrint provides a generator to create templates of a context and behaviros.

$ rails generate blue_print staff user:staff_user
     create  app/blue_prints/staff_context.rb
     create  app/blue_prints/staff_context/staff_user.rb
     invoke  rspec
     create    spec/blue_prints/staff_context_spec.rb
     create    spec/blue_prints/staff_context/staff_user_spec.rb

Contexts

Contexts inherit from BluePrint::Context, live in your app/blue_prints directory.

active_if

This block is used to decide if this context active or not. env is the BluePrint.env. self is passed via BluePrint::Environment#context. By default, this is set as active_if { false }.

class StaffContext < BluePrint::Context
  active_if do |env|
    current_user.try(:staff?)
  end
end

And you can define named active if:

# lib/active_ifs/staff.rb
BluePrint::ActiveIf.new(:staff) do |env|
  current_user.try(:staff?)
end

# app/blue_prints/staff_context.rb
class StaffContext < BluePrint::Context
  active_if :staff
end

Casting

Contexts has casting. This is used to decide classes cast as behaviors if this context active.

class StaffContext < BluePrint::Context
  cast ::User, as: [StaffUser]
end

StaffContext.casting
# =>
#   {
#     User => [ StaffUser ]
#   }

Behaviors

Behaviors extended by BluePrint::Behavior, live in your app/blue_prints/{context} directory.

# app/blue_prints/staff_context/staff_user.rb
module StaffContext::StaffUser
  extend BluePrint::Behavior
end

Methods

Behaviors can have some methods.

# app/blue_prints/staff_context/staff_user.rb
module StaffContext::StaffUser
  extend BluePrint::Behavior

  def user_name
    "staff"
  end
end

# app/models/user.rb
class User < ActiveRecord::Base
  def user_name
    "#{name} san"
  end
end

user = User.new(name: "Magnet")
user.user_name # => "Magnet san"
within_context_of(StaffContext) do
  user.user_name # => "staff"
end

Class Methods

Behaviors can have some class methods.

# app/blue_prints/staff_context/staff_user.rb
module StaffContext::StaffUser
  extend BluePrint::Behavior

  module ClassMethods
    def find(id)
      where(id: id, staff: true).first!
    end
  end
end

# app/models/user.rb
class User < ActiveRecord::Base
end

user = User.create(staff: false)
User.find(user.id) == user # => true
within_context_of(StaffContext) do
  User.find(user.id) # => raise ActiveRecord::NotFound
end

Helper

BluePrint::Helper provides #within_context_of method.

This module includes automatically to some classes. see lib/blue_print/integration.

Contributing

Fork it ( http://github.com/magnet-inc/blue_print/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request