Revised so that Flask-Login become an optional dependency.

setup.cfg

@@ -40,10 +40,14 @@ package_dir =
 packages = find:
 python_requires = >=3.10
 install_requires =
-  flask-login
+  flask
 tests_require =
   unittest
   flask-testing
 
 [options.packages.find]
 where = src
+
+[options.extras_require]
+flask_login =
+    flask-login

src/flask_digest_auth/__init__.py

@@ -20,5 +20,4 @@
 """
 from flask_digest_auth.algo import make_password_hash, calc_response
 from flask_digest_auth.auth import DigestAuth
-from flask_digest_auth.flask_login import init_login_manager
 from flask_digest_auth.test import Client

src/flask_digest_auth/auth.py

@@ -27,7 +27,7 @@ from functools import wraps
 from random import random
 from secrets import token_urlsafe
 
-from flask import g, request, Response, session, abort
+from flask import g, request, Response, session, abort, Flask, Request
 from itsdangerous import URLSafeTimedSerializer, BadData
 from werkzeug.datastructures import Authorization
 
@@ -195,6 +195,63 @@ class DigestAuth:
         """
         self.__get_user = func
 
+    def init_app(self, app: Flask) -> None:
+        """Initializes the Flask application.
+
+        :param app: The Flask application.
+        :return: None.
+        """
+
+        try:
+            from flask_login import LoginManager, login_user
+
+            if not hasattr(app, "login_manager"):
+                raise AttributeError(
+                    "Please run the Flask-Login init-app() first")
+            login_manager: LoginManager = getattr(app, "login_manager")
+
+            @login_manager.unauthorized_handler
+            def unauthorized() -> None:
+                """Handles when the user is unauthorized.
+
+                :return: None.
+                """
+                response: Response = Response()
+                response.status = 401
+                response.headers["WWW-Authenticate"] \
+                    = self.make_response_header(g.digest_auth_state)
+                abort(response)
+
+            @login_manager.request_loader
+            def load_user_from_request(req: Request) -> t.Optional[t.Any]:
+                """Loads the user from the request header.
+
+                :param req: The request.
+                :return: The authenticated user, or None if the
+                    authentication fails
+                """
+                g.digest_auth_state = AuthState()
+                authorization: Authorization = req.authorization
+                try:
+                    if authorization is None:
+                        raise UnauthorizedException
+                    if authorization.type != "digest":
+                        raise UnauthorizedException(
+                            "Not an HTTP digest authorization")
+                    self.authenticate(g.digest_auth_state)
+                    user = login_manager.user_callback(
+                        authorization.username)
+                    login_user(user)
+                    return user
+                except UnauthorizedException as e:
+                    if str(e) != "":
+                        app.logger.warning(str(e))
+                    return None
+
+        except ModuleNotFoundError:
+            raise ModuleNotFoundError(
+                "init_app() is only for Flask-Login integration")
+
 
 class AuthState:
     """The authorization state."""

src/flask_digest_auth/flask_login.py

@@ -1,74 +0,0 @@
-# The Flask HTTP Digest Authentication Project.
-# Author: imacat@mail.imacat.idv.tw (imacat), 2022/11/14
-
-#  Copyright (c) 2022 imacat.
-#
-#  Licensed under the Apache License, Version 2.0 (the "License");
-#  you may not use this file except in compliance with the License.
-#  You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-#  Unless required by applicable law or agreed to in writing, software
-#  distributed under the License is distributed on an "AS IS" BASIS,
-#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-#  See the License for the specific language governing permissions and
-#  limitations under the License.
-
-"""The Flask-Login integration.
-
-"""
-
-import typing as t
-
-from flask import Response, abort, current_app, Request, g
-from flask_login import LoginManager, login_user
-from werkzeug.datastructures import Authorization
-
-from flask_digest_auth.auth import DigestAuth, AuthState
-from flask_digest_auth.exception import UnauthorizedException
-
-
-def init_login_manager(auth: DigestAuth, login_manager: LoginManager) -> None:
-    """Initialize the login manager.
-
-    :param auth: The HTTP digest authentication.
-    :param login_manager: The login manager from FlaskLogin.
-    :return: None.
-    """
-
-    @login_manager.unauthorized_handler
-    def unauthorized() -> None:
-        """Handles when the user is unauthorized.
-
-        :return: None.
-        """
-        response: Response = Response()
-        response.status = 401
-        response.headers["WWW-Authenticate"] = auth.make_response_header(
-            g.digest_auth_state)
-        abort(response)
-
-    @login_manager.request_loader
-    def load_user_from_request(request: Request) -> t.Optional[t.Any]:
-        """Loads the user from the request header.
-
-        :param request: The request.
-        :return: The authenticated user, or None if the authentication fails
-        """
-        g.digest_auth_state = AuthState()
-        authorization: Authorization = request.authorization
-        try:
-            if authorization is None:
-                raise UnauthorizedException
-            if authorization.type != "digest":
-                raise UnauthorizedException(
-                    "Not an HTTP digest authorization")
-            auth.authenticate(g.digest_auth_state)
-            user = login_manager.user_callback(authorization.username)
-            login_user(user)
-            return user
-        except UnauthorizedException as e:
-            if str(e) != "":
-                current_app.logger.warning(str(e))
-            return None

tests/test_flask_login.py

@@ -19,15 +19,13 @@
 
 """
 import typing as t
+import unittest
 from secrets import token_urlsafe
 
-import flask_login
 from flask import Response, Flask
-from flask_login import LoginManager
 from flask_testing import TestCase
 
-from flask_digest_auth import DigestAuth, make_password_hash, Client, \
+from flask_digest_auth import DigestAuth, make_password_hash, Client
-    init_login_manager
 
 _REALM: str = "testrealm@host.com"
 _USERNAME: str = "Mufasa"
@@ -53,7 +51,7 @@ class User:
 class FlaskLoginTestCase(TestCase):
     """The test case with the Flask-Login integration."""
 
-    def create_app(self):
+    def create_app(self) -> Flask:
         """Creates the Flask application.
 
         :return: The Flask application.
@@ -65,11 +63,18 @@ class FlaskLoginTestCase(TestCase):
         })
         app.test_client_class = Client
 
-        login_manager: LoginManager = LoginManager()
+        self.has_flask_login: bool = True
+        try:
+            import flask_login
+        except ModuleNotFoundError:
+            self.has_flask_login = False
+            return app
+
+        login_manager: flask_login.LoginManager = flask_login.LoginManager()
         login_manager.init_app(app)
 
         auth: DigestAuth = DigestAuth(realm=_REALM)
-        init_login_manager(auth, login_manager)
+        auth.init_app(app)
 
         user_db: t.Dict[str, str] \
             = {_USERNAME: make_password_hash(_REALM, _USERNAME, _PASSWORD)}
@@ -117,6 +122,9 @@ class FlaskLoginTestCase(TestCase):
 
         :return: None.
         """
+        if not self.has_flask_login:
+            self.skipTest("Skipped testing Flask-Login integration without it.")
+
         response: Response = self.client.get(self.app.url_for("auth-1"))
         self.assertEqual(response.status_code, 401)
         response = self.client.get(