validate email address

capsulflask/auth.py

@@ -1,4 +1,5 @@
 import functools
+import re
 
 from flask import Blueprint
 from flask import flash
@@ -36,6 +37,9 @@ def login():
 
         if not email:
             error = "Email is required."
+        elif not re.match(r"(^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)", email):
+	        error = "Enter a valid email address."
+
 
         if error is None:
             token = get_model().login(email)

capsulflask/static/style.css

@@ -1,4 +1,10 @@
 .float-right {
   display: inline-block;
   float: right;
+}
+
+.flash {
+  background: red;
+  font-weight: bold;
+  text-align: center;
 }