661c77a901
Rework the tutorial to be more consistent, and to better explain certain principles that drive Falcon's design. Along the way, polish a few other areas of the docs where someone might land during or immediate after walking through the tutorial.
2.6 KiB
Error Handling
When it comes to error handling, you can always directly set the
error status, appropriate response headers, and error body using the
resp object. However, Falcon tries to make things a little
easier by providing a set of error classes you can raise when something
goes wrong. All of these classes inherit from ~.HTTPError.
Falcon will convert any instance or subclass of ~.HTTPError raised by a
responder, hook, or middleware component into an appropriate HTTP
response. The default error serializer supports both JSON and XML. If
the client indicates acceptance of both JSON and XML with equal weight,
JSON will be chosen. Other media types may be supported by overriding
the default serializer via ~.API.set_error_serializer.
Note
If a custom media type is used and the type includes a "+json" or "+xml" suffix, the default serializer will convert the error to JSON or XML, respectively.
All classes are available directly in the falcon package
namespace:
import falcon
class MessageResource(object):
def on_get(self, req, resp):
# ...
raise falcon.HTTPBadRequest(
'TTL Out of Range',
'The message's TTL must be between 60 and 300 seconds, inclusive.'
)
# ...Note also that any exception (not just instances of ~.HTTPError) can be caught,
logged, and otherwise handled at the global level by registering one or
more custom error handlers. See also ~.API.add_error_handler to learn more about this
feature.
Base Class
falcon.HTTPError
Mixins
falcon.http_error.NoRepresentation
Predefined Errors
falcon