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