Changelog for Falcon 1.1.0

Breaking Changes


New & Improved

  • A new bounded_stream property was added to falcon.Request that can be used in place of the stream property to mitigate the blocking behavior of input objects used by some WSGI servers.

  • A new uri_template property was added to Request to expose the template for the route corresponding to the path requested by the user agent.

  • A context property was added to Response to mirror the same property that is already available for Request.

  • JSON-encoded query parameter values can now be retrieved and decoded in a single step via get_param_as_dict().

  • CSV-style parsing of query parameter values can now be disabled.

  • get_param_as_bool() now recognizes “on” and “off” in support of IE’s default checkbox values.

  • An accept_ranges property was added to Response to facilitate setting the Accept-Ranges header.

  • Added the HTTPUriTooLong and HTTPGone error classes.

  • When a title is not specified for HTTPError, it now defaults to the HTTP status text.

  • All parameters are now optional for most error classes.

  • Cookie-related documentation has been clarified and expanded

  • The falcon.testing.Cookie class was added to represent a cookie returned by a simulated request. falcon.testing.Result now exposes a cookies attribute for examining returned cookies.

  • pytest support was added to Falcon’s testing framework. Apps can now choose to either write unittest- or pytest-style tests.

  • The test runner for Falcon’s own tests was switched from nose to pytest.

  • When simulating a request using Falcon’s testing framework, query string parameters can now be specified as a dict, as an alternative to passing a raw query string.

  • A flag is now passed to the process_request middleware method to signal whether or not an exception was raised while processing the request. A shim was added to avoid breaking existing middleware methods that do not yet accept this new parameter.

  • A new CLI utility, falcon-print-routes, was added that takes in a module:callable, introspects the routes, and prints the results to stdout. This utility is automatically installed along with the framework:

    $ falcon-print-routes commissaire:api
    -> /api/v0/status
    -> /api/v0/cluster/{name}
    -> /api/v0/cluster/{name}/hosts
    -> /api/v0/cluster/{name}/hosts/{address}
  • Custom attributes can now be attached to instances of Request and Response. This can be used as an alternative to adding values to the context property, or implementing custom subclasses.

  • get_http_status() was implemented to provide a way to look up a full HTTP status line, given just a status code.


  • When auto_parse_form_urlencoded is set to True, the framework now checks the HTTP method before attempting to consume and parse the body.
  • Before attempting to read the body of a form-encoded request, the framework now checks the Content-Length header to ensure that a non-empty body is expected. This helps prevent bad requests from causing a blocking read when running behind certain WSGI servers.
  • When the requested method is not implemented for the target resource, the framework now raises HTTPMethodNotAllowed, rather than modifying the Request object directly. This improves visibility for custom error handlers and for middleware methods.
  • Error class docstrings have been updated to reflect the latest RFCs.
  • When an error is raised by a resource method or a hook, the error will now always be processed (including setting the appropriate properties of the Response object) before middleware methods are called.
  • A case was fixed in which middleware processing did not continue when an instance of HTTPError or HTTPStatus was raised.
  • The encode() method will now attempt to detect whether the specified string has already been encoded, and return it unchanged if that is the case.
  • The default OPTIONS responder now explicitly sets Content-Length to zero in the response.
  • falcon.testing.Result now assumes that the response body is encoded as UTF-8 when the character set is not specified, rather than raising an error when attempting to decode the response body.
  • When simulating requests, Falcon’s testing framework now properly tunnels Unicode characters through the WSGI interface.
  • import falcon.uri now works, in addition to from falcon import uri.
  • URI template fields are now validated up front, when the route is added, to ensure they are valid Python identifiers. This prevents cryptic errors from being raised later on when requests are routed.
  • When running under Python 3, inspect.signature() is used instead of inspect.getargspec() to provide compatibility with annotated functions.