Add error message when email already exists (#272)

* Add error message when email already exists

* Run black

Author: JAicewizard

website/members/forms.py

@@ -1,4 +1,5 @@
 from PIL import Image
+from django.core.exceptions import ValidationError
 from django.conf import settings
 from django.contrib.auth.forms import SetPasswordForm
 from django.contrib.auth.models import User
@@ -47,6 +48,19 @@ def clean_password(self):
         validate_password(self.data["password"], self.instance)
         return self.data["password"]
 
+    def clean_email(self):
+        email = self.cleaned_data["email"]
+
+        try:
+            User._default_manager.get(email=email)
+        except User.DoesNotExist:
+            return email
+        raise ValidationError(
+            _(
+                "Email already registered. If you are having trouble logging in, you can reset your password."
+            )
+        )
+
     def save(self, commit=True, *args, **kwargs):
         member = super().save(commit=False)
         user = User.objects.create_user(