Added detection to Discover Failures on OpenID (triggered by incorrect hostnames, sites that aren't OpenID providers, etc.) and now handling them gracefully instead of with a 500. Also added open_id_errors templatetag to retrieve those errors for use in an error page (we're using it on the login page) and a test for that templatetag.

Author: Adam Fast

socialregistration/templatetags/socialregistration_tags.py

@@ -1,4 +1,6 @@
+import re
 from django import template
+from django.template import resolve_variable, Variable
 
 register = template.Library()
 
@@ -16,4 +18,39 @@ def render(self, context):
             from django.template.defaulttags import CsrfTokenNode
             return CsrfTokenNode().render(context)
         except ImportError:
-            return u''
+            return u''
+
+
+@register.tag
+def open_id_errors(parser, token):
+    """
+    Retrieve OpenID errors and the provider that caused them from session for display to the user.
+    """
+
+    # This version uses a regular expression to parse tag contents.
+    try:
+        # Splitting by None == splitting by spaces.
+        tag_name, arg = token.contents.split(None, 1)
+    except ValueError:
+        raise template.TemplateSyntaxError, "%r tag requires arguments" % token.contents.split()[0]
+
+    m = re.search(r'(\w+)', arg)
+    if not m:
+        raise template.TemplateSyntaxError, "%r tag had invalid arguments" % tag_name
+    request = m.groups()[0]
+    return OpenIDErrorsNode(request)
+
+class OpenIDErrorsNode(template.Node):
+    def __init__(self, request):
+        self.request = Variable(request)
+
+    def render(self, context):
+        request = self.request.resolve(context)
+        context['openid_error'] = request.session.get('openid_error', False)
+        context['openid_provider'] = request.session.get('openid_provider', '')
+
+        # clear the error once it's been displayed once
+        request.session['openid_error'] = ''
+        request.session['openid_provider'] = ''
+
+        return u''

socialregistration/tests/__init__.py

@@ -0,0 +1 @@
+from socialregistration.tests.templatetags import *

socialregistration/tests/templatetags.py

@@ -0,0 +1,43 @@
+from django import template
+from django.conf import settings
+from django.contrib.sites.models import Site
+from django.http import HttpRequest
+from django.test import TestCase
+
+class MockHttpRequest(HttpRequest):
+
+    def __init__(self, *args, **kwargs):
+        super(MockHttpRequest, self).__init__(*args, **kwargs)
+
+        self.session = {}
+
+class SocialRegistrationTemplateTagTests(TestCase):
+
+    def setUp(self):
+        # set up a site object in case the current site ID doesn't exist
+        site = Site.objects.get_or_create(pk=settings.SITE_ID)
+
+    def render(self, template_string, context={}):
+        """Return the rendered string or the exception raised while rendering."""
+        try:
+            t = template.Template(template_string)
+            c = template.Context(context)
+            return t.render(c)
+        except Exception, e:
+            return e
+
+    def test_open_id_error(self):
+        request = MockHttpRequest()
+
+        request.session['openid_error'] = True
+        request.session['openid_provider'] = 'whizzle'
+
+        template = """{% load socialregistration_tags %}{% open_id_errors request %}{{ openid_error }}|{{ openid_provider }}"""
+        result = self.render(template, {'request': request,})
+        self.assertEqual(result, u'True|whizzle')
+
+        # but accessing it a second time, the error should have cleared.
+        template = """{% load socialregistration_tags %}{% open_id_errors request %}{{ openid_error }}|{{ openid_provider }}"""
+        result = self.render(template, {'request': request,})
+        self.assertEqual(result, u'|')
+

socialregistration/utils.py

@@ -23,6 +23,7 @@
 
 import oauth2 as oauth
 from openid.consumer import consumer as openid
+from openid.consumer.discover import DiscoveryFailure
 from openid.store.interface import OpenIDStore as OIDStore
 from openid.association import Association as OIDAssociation
 

socialregistration/views.py

@@ -19,7 +19,7 @@
 
 from socialregistration.forms import UserForm, ClaimForm, ExistingUser
 from socialregistration.utils import (OAuthClient, OAuthTwitter,
-    OpenID, _https)
+    OpenID, _https, DiscoveryFailure)
 from socialregistration.models import FacebookProfile, TwitterProfile, OpenIDProfile
 
 
@@ -273,7 +273,11 @@ def openid_redirect(request):
         ),
         request.GET.get('openid_provider')
     )
-    return client.get_redirect()
+    try:
+        return client.get_redirect()
+    except DiscoveryFailure:
+        request.session['openid_error'] = True
+        return HttpResponseRedirect(reverse('django.contrib.auth.views.login'))
 
 def openid_callback(request, template='socialregistration/openid.html',
     extra_context=dict(), account_inactive_template='socialregistration/account_inactive.html'):