59 lines
1.6 KiB
Ruby
59 lines
1.6 KiB
Ruby
require_dependency 'declarative_policy/cache'
|
|
require_dependency 'declarative_policy/condition'
|
|
require_dependency 'declarative_policy/dsl'
|
|
require_dependency 'declarative_policy/preferred_scope'
|
|
require_dependency 'declarative_policy/rule'
|
|
require_dependency 'declarative_policy/runner'
|
|
require_dependency 'declarative_policy/step'
|
|
|
|
require_dependency 'declarative_policy/base'
|
|
|
|
module DeclarativePolicy
|
|
class << self
|
|
def policy_for(user, subject, opts = {})
|
|
cache = opts[:cache] || {}
|
|
key = Cache.policy_key(user, subject)
|
|
|
|
cache[key] ||= class_for(subject).new(user, subject, opts)
|
|
end
|
|
|
|
def class_for(subject)
|
|
return GlobalPolicy if subject == :global
|
|
return NilPolicy if subject.nil?
|
|
|
|
subject = find_delegate(subject)
|
|
|
|
subject.class.ancestors.each do |klass|
|
|
next unless klass.name
|
|
|
|
begin
|
|
policy_class = "#{klass.name}Policy".constantize
|
|
|
|
# NOTE: the < operator here tests whether policy_class
|
|
# inherits from Base. We can't use #is_a? because that
|
|
# tests for *instances*, not *subclasses*.
|
|
return policy_class if policy_class < Base
|
|
rescue NameError
|
|
nil
|
|
end
|
|
end
|
|
|
|
raise "no policy for #{subject.class.name}"
|
|
end
|
|
|
|
private
|
|
|
|
def find_delegate(subject)
|
|
seen = Set.new
|
|
|
|
while subject.respond_to?(:declarative_policy_delegate)
|
|
raise ArgumentError, "circular delegations" if seen.include?(subject.object_id)
|
|
seen << subject.object_id
|
|
subject = subject.declarative_policy_delegate
|
|
end
|
|
|
|
subject
|
|
end
|
|
end
|
|
end
|