Validate username field on registration

* validate username with regex on registration (bootstrap3 frontent does
  not handle regex correctly. XXX) -> account/forms.py
* small update to registration page title display style

2 files changed, 26 insertions, 2 deletions

diff --git a/account/forms.py b/account/forms.py
index daa6683..aa021ac 100644
--- a/account/forms.py
+++ b/account/forms.py
@@ -10,11 +10,13 @@ from django.contrib.auth.models import User
 from django.contrib.sites.models import Site, RequestSite
 from django.utils.translation import ugettext_lazy as _
 
-from registration.forms import RegistrationFormUniqueEmail
+from registration.forms import RegistrationForm, RegistrationFormUniqueEmail
 from captcha.fields import ReCaptchaField
 
 from account.models import UserProfile, UserFile
 
+import re
+
 
 class UserRegForm(RegistrationFormUniqueEmail):
     """
@@ -44,6 +46,26 @@ class UserRegForm(RegistrationFormUniqueEmail):
     #            'identity',
     #    ]
 
+    def clean_username(self):
+        """
+        It is required to check whether the username matches the
+        specified regular expression.
+        Because the frontend does not correctly validate RegexField.
+        XXX: howto deal with 'RegexField' in 'django-bootstrap3'
+        """
+        username = self.cleaned_data['username']
+        # check whether matches
+        username_p = re.compile(r'^[a-zA-Z_][a-zA-Z0-9_.@+-]{3,29}')
+        username_m = username_p.match(username)
+        if not username_m:
+            raise forms.ValidationError(_("4-30 characters. Start with letters and underscore. Contains letters, digits and _.@+- characters."), code='invalid')
+        # check whether exists
+        existing = User.objects.filter(username__iexact=username)
+        if existing.exists():
+            raise forms.ValidationError(_("A user with that username already exists."), code='invalid')
+        else:
+            return username
+
 
 class ResendEmailForm(forms.Form):
     """
diff --git a/templates/registration/registration_form.html b/templates/registration/registration_form.html
index 61de0ff..1bf7642 100644
--- a/templates/registration/registration_form.html
+++ b/templates/registration/registration_form.html
@@ -9,7 +9,9 @@
 
 {% block content %}
   <div class="container">
-    <h2>注册账户</h2>
+    <div class="col-md-offset-2">
+      <h2>注册账户</h2>
+    </div>
     <br>
 
     <form role="form" class="form-horizontal" method="post">