Merge pull request #310 from ankane/lazy_load_key

Only load key if needed

lib/attr_encrypted.rb

@@ -368,15 +368,21 @@ def encrypted_attributes
       # Returns attr_encrypted options evaluated in the current object's scope for the attribute specified
       def evaluated_attr_encrypted_options_for(attribute)
         evaluated_options = Hash.new
-        attribute_option_value = encrypted_attributes[attribute.to_sym][:attribute]
-        encrypted_attributes[attribute.to_sym].map do |option, value|
-          evaluated_options[option] = evaluate_attr_encrypted_option(value)
+        attributes = encrypted_attributes[attribute.to_sym]
+        attribute_option_value = attributes[:attribute]
+
+        [:if, :unless, :value_present, :allow_empty_value].each do |option|
+          evaluated_options[option] = evaluate_attr_encrypted_option(attributes[option])
         end
 
         evaluated_options[:attribute] = attribute_option_value
 
         evaluated_options.tap do |options|
           if options[:if] && !options[:unless] && options[:value_present] || options[:allow_empty_value]
+            (attributes.keys - evaluated_options.keys).each do |option|
+              options[option] = evaluate_attr_encrypted_option(attributes[option])
+            end
+
             unless options[:mode] == :single_iv_and_salt
               load_iv_for_attribute(attribute, options)
             end

test/attr_encrypted_test.rb

@@ -478,4 +478,13 @@ def test_encrypted_attributes_state_is_not_shared
     assert_equal :encrypting, user.encrypted_attributes[:ssn][:operation]
     assert_nil another_user.encrypted_attributes[:ssn][:operation]
   end
+
+  def test_should_not_by_default_generate_key_when_attribute_is_empty
+    user = User.new
+    calls = 0
+    user.stub(:secret_key, lambda { calls += 1; SECRET_KEY }) do
+      user.ssn
+    end
+    assert_equal 0, calls
+  end
 end