lib/blind_index.rb in blind_index-0.1.1 vs lib/blind_index.rb in blind_index-0.2.0

@@ -14,22 +14,29 @@
     raise BlindIndex::Error, "Missing key for blind index" unless key
 
     # apply expression
     value = expression.call(value) if expression
 
-    # generate hash
-    digest = OpenSSL::Digest::SHA256.new
-    value = OpenSSL::PKCS5.pbkdf2_hmac(value.to_s, key, iterations, digest.digest_length, digest)
+    unless value.nil?
+      # generate hash
+      digest = OpenSSL::Digest::SHA256.new
+      value = OpenSSL::PKCS5.pbkdf2_hmac(value.to_s, key, iterations, digest.digest_length, digest)
 
-    # encode
-    [value].pack("m")
+      # encode
+      [value].pack("m")
+    end
   end
 end
 
 ActiveSupport.on_load(:active_record) do
   require "blind_index/extensions"
   extend BlindIndex::Model
-  ActiveRecord::TableMetadata.prepend(BlindIndex::Extensions::TableMetadata)
+
+  if defined?(ActiveRecord::TableMetadata)
+    ActiveRecord::TableMetadata.prepend(BlindIndex::Extensions::TableMetadata)
+  else
+    ActiveRecord::PredicateBuilder.singleton_class.prepend(BlindIndex::Extensions::PredicateBuilder)
+  end
 
   unless ActiveRecord::VERSION::STRING.start_with?("5.1.")
     ActiveRecord::Validations::UniquenessValidator.prepend(BlindIndex::Extensions::UniquenessValidator)
   end
 end