Feature custom callback without custom state

docs/index.rst

@@ -91,6 +91,8 @@ To do this, add the decorator `oidc.custom_callback` to your callback function.
 This will get the (json-serializable) custom state that you passed in as
 `customstate` to `oidc.redirect_to_auth_server`.
 Note that to use this, you will need to set `OVERWRITE_REDIRECT_URI`.
+Use parameter `custom` if you want to use custom state, `destination` if you
+want to keep default state settings.
 
 Example::
 
@@ -99,7 +101,7 @@ Example::
         return oidc.redirect_to_auth_server(None, flask.request.values)
 
     @app.route('/custom_callback')
-    @oidc.custom_callback
+    @oidc.custom_callback('custom')
     def callback(data):
         return 'Hello. You submitted %s' % data
 

flask_oidc/__init__.py

@@ -666,21 +666,23 @@ def _is_id_token_valid(self, id_token):
 
     WRONG_GOOGLE_APPS_DOMAIN = 'WRONG_GOOGLE_APPS_DOMAIN'
 
-    def custom_callback(self, view_func):
-        """
-        Wrapper function to use a custom callback.
-        The custom OIDC callback will get the custom state field passed in with
-        redirect_to_auth_server.
-        """
-        @wraps(view_func)
-        def decorated(*args, **kwargs):
-            plainreturn, data = self._process_callback('custom')
-            if plainreturn:
-                return data
-            else:
-                return view_func(data, *args, **kwargs)
-        self._custom_callback = decorated
-        return decorated
+    def custom_callback(self, statefield='custom'):
+        def _custom_callback(view_func):
+            """
+            Wrapper function to use a custom callback.
+            The custom OIDC callback will get the custom state field passed in with
+            redirect_to_auth_server.
+            """
+            @wraps(view_func)
+            def decorated(*args, **kwargs):
+                plainreturn, data = self._process_callback(statefield)
+                if plainreturn:
+                    return data
+                else:
+                    return view_func(data, *args, **kwargs)
+            self._custom_callback = decorated
+            return decorated
+        return _custom_callback
 
     def _oidc_callback(self):
         plainreturn, data = self._process_callback('destination')