manager: export all user attributes (fixes #13587)

src/authentic2/manager/user_views.py

@@ -1,4 +1,5 @@
 import uuid
+import collections
 
 from django.db import models
 from django.utils.translation import ugettext_lazy as _, ugettext
@@ -14,6 +15,8 @@ from django.http import HttpResponseRedirect, QueryDict
 from django.views.generic.detail import SingleObjectMixin
 from django.views.generic import View
 
+from import_export.fields import Field
+
 from authentic2.constants import SWITCH_USER_SESSION_KEY
 from authentic2.models import Attribute, PasswordReset
 from authentic2.utils import switch_user, send_password_reset_mail, redirect, send_email_change_email
@@ -303,6 +306,19 @@ class UsersExportView(ExportMixin, UsersView):
     resource_class = UserResource
     export_prefix = 'users-'
 
+    def get_resource(self):
+        '''Subclass default UserResource class to dynamically add field for extra attributes'''
+        attrs = collections.OrderedDict()
+        for attribute in Attribute.objects.all():
+            attrs['attribute_%s' % attribute.name] = Field(attribute='attributes__%s' % attribute.name)
+        custom_class = type('UserResourceClass', (self.resource_class,), attrs)
+        return custom_class()
+
+    def get_queryset(self):
+        '''Prefetch attribute values.'''
+        qs = super(UsersExportView, self).get_queryset()
+        return qs.prefetch_related('attribute_values', 'attribute_values__attribute')
+
 users_export = UsersExportView.as_view()