add support for anonymous abilities

1 files changed, 22 insertions, 4 deletions

diff --git a/app/policies/base_policy.rb b/app/policies/base_policy.rb
index 3f52b0b005a..10ce38329c4 100644
--- a/app/policies/base_policy.rb
+++ b/app/policies/base_policy.rb
@@ -1,14 +1,21 @@
 class BasePolicy
+  def self.abilities(user, subject)
+    new(user, subject).abilities
+  end
+
+  attr_reader :user, :subject
   def initialize(user, subject)
     @user = user
     @subject = subject
   end
 
   def abilities
-    @can = Set.new
-    @cannot = Set.new
-    generate!
-    @can - @cannot
+    return anonymous_abilities if @user.nil?
+    collect_rules { rules }
+  end
+
+  def anonymous_abilities
+    collect_rules { anonymous_rules }
   end
 
   def generate!
@@ -22,4 +29,15 @@ class BasePolicy
   def cannot!(*rules)
     @cannot.merge(rules)
   end
+
+  private
+
+  def collect_rules(&b)
+    return Set.new if @subject.nil?
+
+    @can = Set.new
+    @cannot = Set.new
+    yield
+    @can - @cannot
+  end
 end