Allow JWT fields to come from a callable.

README.rst

@@ -49,6 +49,10 @@ Then modify settings.py:
             ...
         ],
 
+        # You can also populate the JWT fields by configuring your own callable. The
+        # callable should return a dictionary. The function should optionally accept user.
+        'CALLABLE': 'some.module.with.a.function',
+
         # KEY can also be a tuple in order to specify public and private keys.
         'KEY': 'string value or path to PEM key file',
 

django_session_jwt/__init__.py

@@ -0,0 +1,2 @@
+def get_fields(user=None):
+    return { 'foo': 'bar' }

django_session_jwt/middleware/session.py

@@ -74,10 +74,21 @@ def _parse_fields(fields):
     return fields
 
 
+def _parse_callable(f):
+    if not f:
+        return
+
+    module_name, _, f_name = f.rpartition('.')
+    m = import_module(module_name)
+
+    return getattr(m, f_name)
+
+
 DJANGO_SESSION_JWT = getattr(settings, 'DJANGO_SESSION_JWT', {})
 SESSION_FIELD = DJANGO_SESSION_JWT.get('SESSION_FIELD', 'sk')
 KEY, PUBKEY, ALGO = _parse_key(DJANGO_SESSION_JWT.get('KEY', settings.SECRET_KEY))
 FIELDS = _parse_fields(DJANGO_SESSION_JWT.get('FIELDS', []))
+CALLABLE = _parse_callable(DJANGO_SESSION_JWT.get('CALLABLE'))
 EXPIRES = DJANGO_SESSION_JWT.get('EXPIRES', None)
 LOGGER = logging.getLogger(__name__)
 LOGGER.addHandler(logging.NullHandler())
@@ -134,6 +145,9 @@ def create_jwt(user, session_key, expires=None):
             LOGGER.warning('Could not get missing field %s from user', attrname)
             continue
 
+    if CALLABLE:
+        fields.update(CALLABLE(user))
+
     return jwt.encode(fields, KEY, algorithm=ALGO).decode('utf8')
 
 

django_session_jwt/settings.py

@@ -119,6 +119,7 @@
         ('username', 'u', 'username'),
         ('email', 'e', 'email'),
     ],
+    'CALLABLE': 'django_session_jwt.get_fields',
     'KEY': SECRET_KEY,
     # The default, uncomment to override:
     # 'SESSION_FIELD': 'sk',

django_session_jwt/tests.py

@@ -77,6 +77,7 @@ def test_login(self):
         self.assertTrue('username' in fields) # long form
         self.assertTrue('e' in fields)        # short form
         self.assertTrue('email' in fields)    # long form
+        self.assertTrue('foo' in fields)      # from callable
 
     def test_session(self):
         "Test persisting session data"
@@ -114,3 +115,4 @@ def test_login(self):
         self.assertTrue('username' in fields) # long form
         self.assertTrue('e' in fields)        # short form
         self.assertTrue('email' in fields)    # long form
+        self.assertTrue('foo' in fields)      # from callable