Resolve post logout redirect URIs for routes created by blueprints

docs/quickstart.md

@@ -160,9 +160,22 @@ def logout():
     return "You've been successfully logged out!"
 ```
 
-If the logout view is mounted under a custom endpoint (other than the default, which is 
-[the name of the view function](https://flask.palletsprojects.com/en/2.0.x/api/#flask.Flask.route)), or if using Blueprints, you
-must specify the full URL in the Flask-pyoidc configuration using `post_logout_redirect_uris`:
+If you are using Blueprints to create routes, you can provide `logout_view` argument which takes
+[name of the view function](https://flask.palletsprojects.com/en/2.0.x/api/#flask.Flask.route) as parameter. This
+argument is used to resolve URL for `post_logout_redirect_uris`.
+```python
+from flask import Blueprint
+
+blueprint = Blueprint(name='api', import_name=__name__)
+
+@blueprint.route('/logout')
+@auth.oidc_logout(logout_view='api.logout')
+def logout():
+    return "You've been successfully logged out!"
+```
+
+`logout_view` argument is optional to provide in the decorator because you can directly specify
+`post_logout_redirect_uris` as complete URL in the Flask-pyoidc configuration:
 ```python
 ClientMetadata(..., post_logout_redirect_uris=['https://example.com/post_logout']) # if using static client registration
 ClientRegistrationInfo(..., post_logout_redirect_uris=['https://example.com/post_logout']) # if using dynamic client registration 

src/flask_pyoidc/flask_pyoidc.py

@@ -90,7 +90,7 @@ def init_app(self, app):
 
     def _get_urls_for_logout_views(self):
         try:
-            return [url_for(view.__name__, _external=True) for view in self._logout_views]
+            return [url_for(view, _external=True) for view in self._logout_views]
         except BuildError:
             logger.error('could not build url for logout view, it might be mounted under a custom endpoint')
             raise
@@ -260,25 +260,32 @@ def _logout(self, post_logout_redirect_uri):
             return redirect(end_session_request.request(client.provider_end_session_endpoint), 303)
         return None
 
-    def oidc_logout(self, view_func):
-        self._logout_views.append(view_func)
+    def oidc_logout(self, logout_view: Optional[str] = None):
 
-        @functools.wraps(view_func)
-        def wrapper(*args, **kwargs):
-            if 'state' in flask.request.args:
-                # returning redirect from provider
-                if flask.request.args['state'] != flask.session.pop('end_session_state', None):
-                    logger.error("Got unexpected state '%s' after logout redirect.", flask.request.args['state'])
-                return view_func(*args, **kwargs)
+        def logout_decorator(view_func):
+
+            @functools.wraps(view_func)
+            def wrapper(*args, **kwargs):
+                if 'state' in flask.request.args:
+                    # returning redirect from provider
+                    if flask.request.args['state'] != flask.session.pop('end_session_state', None):
+                        logger.error("Got unexpected state '%s' after logout redirect.", flask.request.args['state'])
+                    return view_func(*args, **kwargs)
+
+                post_logout_redirect_uri = flask.request.url
+                redirect_to_provider = self._logout(post_logout_redirect_uri)
+                if redirect_to_provider:
+                    return redirect_to_provider
 
-            post_logout_redirect_uri = flask.request.url
-            redirect_to_provider = self._logout(post_logout_redirect_uri)
-            if redirect_to_provider:
-                return redirect_to_provider
+                return view_func(*args, **kwargs)
 
-            return view_func(*args, **kwargs)
+            return wrapper
 
-        return wrapper
+        if callable(logout_view):
+            self._logout_views.append(logout_view.__name__)
+            return logout_decorator(logout_view)
+        self._logout_views.append(logout_view)
+        return logout_decorator
 
     def error_view(self, view_func):
         self._error_view = view_func

tests/test_flask_pyoidc.py

@@ -662,6 +662,21 @@ def test_logout_handles_no_user_session(self):
 
         self.assert_view_mock(logout_view_mock, result)
 
+    def test_oidc_logout_when_endpoint_name_is_provided(self):
+        authn = self.init_app()
+        # Decorator with an argument.
+        view_func1 = authn.oidc_logout(logout_view='logout1')(self.get_view_mock('logout1'))
+        self.app.add_url_rule('/logout1', 'logout1', view_func=view_func1)
+        view_func2 = authn.oidc_logout(logout_view='test.logout')(self.get_view_mock('logout2'))
+        self.app.add_url_rule('/logout2', 'test.logout', view_func=view_func2)
+        # Decorator without an argument.
+        view_func3 = authn.oidc_logout(self.get_view_mock('logout3'))
+        self.app.add_url_rule('/logout3', 'logout3', view_func=view_func3)
+
+        with self.app.app_context():
+            assert authn._get_urls_for_logout_views() == [f'http://{self.CLIENT_DOMAIN}{endpoint}'
+                                                          for endpoint in ('/logout1', '/logout2', '/logout3')]
+
     def test_authentication_error_response_calls_to_error_view_if_set(self):
         state = 'test_tate'
         error_response = {'error': 'invalid_request', 'error_description': 'test error'}