Handle undefined values in form submission (#39)

* Fix exceptions if frontend value is sent as `undefined`

* Try to fix test

* Comment my supposed fix

* format

* Remove comments

---------

Co-authored-by: Tiberiu Ichim <tiberiu.ichim@gmail.com>

src/collective/volto/formsupport/restapi/services/submit_form/post.py

@@ -201,7 +201,7 @@ def get_reply_to(self):
                     if field_id:
                         for data in self.form_data.get("data", ""):
                             if data.get("field_id", "") == field_id:
-                                return data["value"]
+                                return data.get("value", "")
 
         return self.form_data.get("from", "") or self.block.get("default_from", "")
 
@@ -367,7 +367,7 @@ def attach_xml(self, msg):
         for field in self.filter_parameters():
             SubElement(
                 xmlRoot, "field", name=field.get("custom_field_id", field["label"])
-            ).text = str(field["value"])
+            ).text = str(field.get("value", ""))
 
         doc = ElementTree(xmlRoot)
         doc.write(output, encoding="utf-8", xml_declaration=True)

src/collective/volto/formsupport/tests/test_send_action_form.py

@@ -12,13 +12,13 @@
 from plone.restapi.testing import RelativeSession
 from Products.MailHost.interfaces import IMailHost
 from six import StringIO
-import xml.etree.ElementTree as ET
 from zope.component import getUtility
 
-import transaction
-import unittest
 import base64
 import os
+import transaction
+import unittest
+import xml.etree.ElementTree as ET
 
 
 class TestMailSend(unittest.TestCase):