Allow date_value= and time_value= to handle nils.

Also adds specs for the existing (not null) behavior.

lib/surveyor/models/response_methods.rb

@@ -55,15 +55,25 @@ def time_value
       end
 
       def time_value=(val)
-        self.datetime_value = Time.zone.parse("#{Date.today.to_s} #{val}") ? Time.zone.parse("#{Date.today.to_s} #{val}").to_datetime : nil
+        self.datetime_value =
+          if val && time = Time.zone.parse("#{Date.today.to_s} #{val}")
+            time.to_datetime
+          else
+            nil
+          end
       end
 
       def date_value
         read_attribute(:datetime_value).strftime( date_format ) unless read_attribute(:datetime_value).blank?
       end
 
       def date_value=(val)
-        self.datetime_value = Time.zone.parse(val) ? Time.zone.parse(val).to_datetime : nil
+        self.datetime_value =
+          if val && time = Time.zone.parse(val)
+            time.to_datetime
+          else
+            nil
+          end
       end
 
       def time_format

spec/models/response_spec.rb

@@ -174,3 +174,33 @@
     end
   end
 end
+
+describe Response, 'value methods' do
+  let(:response) { Response.new }
+
+  describe '#date_value=' do
+    it 'accepts a parseable date string' do
+      response.date_value = '2010-01-15'
+      response.datetime_value.strftime('%Y %m %d').should == '2010 01 15'
+    end
+
+    it 'clears when given nil' do
+      response.datetime_value = Time.new
+      response.date_value = nil
+      response.datetime_value.should be_nil
+    end
+  end
+
+  describe 'time_value=' do
+    it 'accepts a parseable time string' do
+      response.time_value = '11:30'
+      response.datetime_value.strftime('%H %M %S').should == '11 30 00'
+    end
+
+    it 'clears when given nil' do
+      response.datetime_value = Time.new
+      response.time_value = nil
+      response.datetime_value.should be_nil
+    end
+  end
+end