@api.errorhandler doesn't work

[lifehackett]

Thank you for forking this project. It does not seem like this issue is addressed yet nor did I see an existing issue mentioning it, so porting it over to this project. I believe these 3 issues capture the problem well enough, but if you need additional information, just shout.

noirbizarre/flask-restplus#764
noirbizarre/flask-restplus#744
noirbizarre/flask-restplus#693

BTW, the work around using PROPOPGATE_EXCEPTIONS did not work for me.

Thanks

[j5awry]

We're going to need more info. 693 was closed with the fix (which our first release should have). 764 was mentioned as a dupe by the opener of 693

It should be fixed in our codeline from commit noirbizarre/flask-restplus@de38220

if you are still seeing the issue, please provide more information.

[nlarusstone]

@brmzkw as you commented in noirbizarre/flask-restplus#693 (comment), this issue does not appear to be fixed (here's the corresponding flask-restx issue)

[brmzkw]

Thanks for the highlight. I'm removing flask-restx from my projects, but feel free to ask if I can provide more help or details.

[papasax]

@j5awry : Here is some more info. Apparently this bug only occurs when FLASK is in DEBUG mode. If you turn this off everything is fine.

[andresDM]

@j5awry Thanks for the framework, it is super useful! Some extra info regarding this topic:

In my case the errorhandler don't work in a name space when implementing blueprints as in: Multiple APIs with reusable namespaces.

I do not face this problem when registering the handlers in the Blueprint or the Api object. I think registering in the namespaces is quite useful though.

[papasax]

I looked more deeply and found this bug:
In api.py, line 653:

When propagate_exceptions is set, do not return the exception to the

client if a handler is configured for the exception.

The tests forget to check the child error handler
if (
not isinstance(e, HTTPException)
and current_app.propagate_exceptions
and not isinstance(e, tuple(self.error_handlers.keys()))
)

should include the childs:
if (
not isinstance(e, HTTPException)
and current_app.propagate_exceptions
and not isinstance(e, tuple(self.error_handlers.keys()))
and not isinstance(e, tuple(self.own_and_child_error_handlers.keys()))
)

But it does not fix everything, since if 1 exception handler is registered in 2 different namespace, it will always call the first.

[gamgi]

It's possible to work around this bug by manually setting api.error_handlers.

Example namespaced API

# api/my_api.py
from flask_restx import Namespace, Resource

api = Namespace("my_api")

@api.route('/foo')
class MyResource(Resource):
    def get(self):
        raise RuntimeError('bar')

and then

# api/__init__.py
from flask import Blueprint
from flask_restx import Api
from .my_api import api as my_api

blueprint = Blueprint('api', __name__)
api = Api(blueprint, title='My Title')

api.add_namespace(my_api)

@api.errorhandler
def handle_exception(error: Exception):
    """When an unhandled exception is raised"""
    message = "Error: " + getattr(error, 'message', str(error))
    return {'message': message}, getattr(error, 'code', 500)


# error handlers should work with @api.errorhandler, as per https://flask-restx.readthedocs.io/en/latest/errors.html
# but there is a bug, this is a workaround for https://github.com/python-restx/flask-restx/issues/27
api._default_error_handler = Exception
api.error_handlers[Exception] = handle_exception

[mittal-umang]

@gamgi

Hi tried this work around but it doesn't work unfortunately.

@SteadBytes is there any plan on fixing this issue.

[j5awry]

There have been multiple bugfixes for errorhandling pushed in the last two releases. Is this still an issue?

[szymonpru]

@j5awry Yes, I have still this problem.