Contextuable

This gem has been renamed to Dystruct

the new repo is: https://github.com/arturictus/dystruct

Better Structs for many applications.

Installation

Add this line to your application's Gemfile:

gem 'contextuable'

And then execute:

$ bundle

Or install it yourself as:

$ gem install contextuable

Usage

Extended OpenStruct:

  context = Contextuable.new(name: 'John', surname: 'Doe')
  context.name # => 'John'
  context.name_provided? # => true
  context.surname # => 'Doe'
  context.foo_provided? # => false
  context.foo_not_provided? # => true
  context.foo = :bar
  context.foo_provided? # => true
  context.foo_not_provided? # => false
  context.foo # => :bar
  context.to_h # => {:name=>"John", :surname=>"Doe", :foo=>:bar}

more complex example

class Input < Contextuable
  permit  :name, :city, :address, :phone_number, :free_text, :country_code,
    :country, :zip, :types
  defaults types: ['lodging']
  aliases :name, :hotel_name
  aliases :phone_number, :telephone

  def long_name
    [name, address, city].join(', ')
  end

  def types
    Array.wrap(args[:types])
  end
end

i = Input.new(name: 'Hotel', city: 'Barcelona', address: 'Happy street', not_permitted: 'dangerous')
i.types
# => ["lodging"]
i.long_name
# => "Hotel, Happy street, Barcelona"
i.name
# => "Hotel"
i.hotel_name
# => "Hotel"
i.phone_number_provided?
# => false
i.not_permitted
# => NoMethodError: undefined method

Building better Structs

no_method_error

class Example < Contextuable
  no_method_error false
end

Example.new(foo: :bar).hello # => nil

class Example < Contextuable
  no_method_error
end

Example.new(foo: :bar).hello # => => NoMethodError: undefined method

required

class Example < Contextuable
  required :required_arg
end

Example.new(foo: :bar)
#=> Error Contextuable::RequiredFieldNotPresent

aliases

class Example < Contextuable
  aliases :hello, :greeting, :welcome
end
ex = Example.new(hello: 'Hey!')
# => #<Example:0x007fd88ba30398 @args={:hello=>"Hey!"}>
ex.hello
# => "Hey!"
ex.greeting
# => "Hey!"
ex.welcome
# => "Hey!"

defaults

class Example2 < Contextuable
  defaults foo: :bar, bar: :foo
end
ex = Example2.new
ex.foo
# => :bar
ex.bar
# => :foo
ex.foo = :hello
ex.foo
# => :hello

ex2 = Example2.new(foo: 'something', bar: true)
ex2.foo
# => 'something'
ex2.bar
# => true

ensure_presence

class EnsurePresence < Contextuable
  ensure_presence :foo
end
EnsurePresence.new(hello: 'asdf')
#=> Error: Contextuable::PresenceRequired

EnsurePresence.new(foo: nil)
#=> Error: Contextuable::PresenceRequired

EnsurePresence.new(foo: '').foo #=> ""

permit

per = Permit.new(foo: :bar, hello: 'Hey!', bar: 'bla', yuju: 'dangerous')
 => #<Permit:0x007fd88b9dd878 @args={:foo=>:bar, :hello=>"Hey!"}>
per.foo #=> :bar
per.yuju #=> nil

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake rspec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

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

License

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