Simple functional authorization library for ruby. Inspired by transproc and dry project
Add this line to your application's Gemfile:
gem 'kan'And then execute:
$ bundle
Or install it yourself as:
$ gem install kan
class Post::Abilities
include Kan::Abilities
register('read') { |_, _| true }
register('edit') { |user, post| user.id == post.user_id }
register('delete') { |_, _| false }
endAlso, you can register more than one ability in one place and use string or symbol keys:
class Post::AdminAbilities
include Kan::Abilities
register(:read, :edit, :delete) { |user, _| user.admin? }
end
class Comments::Abilities
include Kan::Abilities
register('read') { |_, _| true }
register('edit') { |user, _| user.admin? }
register(:delete) do |user, comment|
user.id == comment.user_id && comment.created_at < Time.now + TEN_MINUTES
end
endabilities = Kan::Application.new(
post: Post::Abilities.new,
comment: Comments::Abilities.new
)
abilities['post.read'].call(current_user, post) # => true
abilities['post.delete'].call(current_user, post) # => false
abilities['comment.delete'].call(current_user, post) # => falseBy default Kan use proc { true } as a default ability block:
abilities['comment.invalid'].call(current_user, post) # => trueBut you can rewrite it
admin_abilities = Kan::Application.new(
post: Post::AdminAbilities.new(default_ability_block: proc { false }),
comment: Comments::Abilities.new,
)
admin_abilities['post.delete'].call(current_user, post) # => false
admin_abilities['post.delete'].call(admin_user, post) # => true
admin_abilities['post.invalid'].call(current_user, post) # => falseYou can provide array of abilities for each scope and Kan will return true if at least one ability return true:
global_abilities = Kan::Application.new(
post: [Post::Abilities.new, Post::AdminAbilities.new],
comment: Comments::Abilities.new
)
global_abilities['post.edit'].call(current_user, post) # => false
global_abilities['post.edit'].call(owner_user, post) # => true
global_abilities['post.edit'].call(admin_user, post) # => trueYou can use strings or symbols and then use it as name of ability
class Post::Abilities
include Kan::Abilities
register(:edit) { |_, _| true }
register_alias(:correct, 'edit')
end
abilities = Kan::Application.new(
post: Post::Abilities.new
)
abilities['post.correct'].call(current_user, post) # => trueYou can provide callable object (that respond to #call) that accepts ability_name and payload params to after_call_callback param of your ability:
admin_abilities = Kan::Application.new(
post: Post::AdminAbilities.new(after_call_callback: -> (ability_name, payload) { ... }),
comment: Comments::Abilities.new,
)
admin_abilities['post.read'].call(current_user, post) # => falseYour object will be executed after calling ability.
Bug reports and pull requests are welcome on GitHub at https://github.com/davydovanton/kan. 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.
Just send PR with changes in docs/ folder.
Just clone repository and call:
$ bundle install
$ bundle exec rspec
This project exists thanks to all the people who contribute.
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The gem is available as open source under the terms of the MIT License.
Everyone interacting in the Kan project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.