Merge with master.

app/utils.py

@@ -1,3 +1,5 @@
+import re
+
 from functools import wraps
 from flask import (abort, session)
 
@@ -28,6 +30,11 @@ class BrowsableItem(object):
         pass
 
 
+class InvalidEmailError(Exception):
+    def __init__(self, message):
+        self.message = message
+
+
 class InvalidPhoneError(Exception):
     def __init__(self, message):
         self.message = message
@@ -74,6 +81,19 @@ def format_phone_number(number):
     return '+447{}{}{}'.format(*re.findall('...', number))
 
 
+def validate_email_address(email_address):
+    if re.match(r"(^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)", email_address):
+        return
+    raise InvalidEmailError('Not a valid email address')
+
+
+def validate_recipient(recipient, template_type):
+    return {
+        'email': validate_email_address,
+        'sms': validate_phone_number
+    }[template_type](recipient)
+
+
 def user_has_permissions(*permissions):
     def wrap(func):
         @wraps(func)