README.md
# BluePrint
[](http://badge.fury.io/rb/blue_print)
[](https://travis-ci.org/magnet-inc/blue_print)
[](https://coveralls.io/r/magnet-inc/blue_print)
[](https://codeclimate.com/github/magnet-inc/blue_print)
[](https://gemnasium.com/magnet-inc/blue_print)
The behavior switching framework. inspired by [DCI](http://en.wikipedia.org/wiki/Data,_context_and_interaction).
## 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:
```ruby
gem 'blue_print', '~> 1.3.0'
```
## Usage
### Integration
BluePrint provides some integrations. Now supported libraries:
- [Ruby on Rails](http://rubyonrails.org/) >= 3.1
- [Grape](http://intridea.github.io/grape/)
- [Draper](https://github.com/drapergem/draper)
- [RSpec](https://github.com/rspec)
### Rails Generators
BluePrint provides a generator to create templates of a context and behaviros.
```bash
$ 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 }`.
```ruby
class StaffContext < BluePrint::Context
active_if do |env|
current_user.try(:staff?)
end
end
```
And you can define named active if:
```ruby
# 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.
```ruby
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.
```ruby
# app/blue_prints/staff_context/staff_user.rb
module StaffContext::StaffUser
extend BluePrint::Behavior
end
```
#### Methods
Behaviors can have some methods.
```ruby
# 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")
StaffContext.deactivate!
user.user_name # => "Magnet san"
StaffContext.activate!
user.user_name # => "staff"
```
#### Class Methods
Behaviors can have some class methods.
```ruby
# 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)
StaffContext.deactivate!
User.find(user.id) == user # => true
StaffContext.activate!
User.find(user.id) # => raise ActiveRecord::NotFound
```
### Helper
`BluePrint::Helper` provides `#within_context_of` and `#without_context_of`.
This module includes automatically to some classes. see [lib/blue_print/integration](https://github.com/magnet-inc/blue_print/tree/master/lib/blue_print/integration).
## Contributing
1. Fork it ( http://github.com/magnet-inc/blue_print/fork )
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