tastypie not returning NotFound exception error message

[Brian Murray]

If one uses the package-version-new-buckets resource there is a special NotFound error message which should be raised (I believe). The code for raising that follows:

        previous_version = request.GET.get('previous_version', None)
        new_version = request.GET.get('new_version', None)
        if not launchpad.is_valid_source_version(src_package, previous_version):
            raise NotFound('%s version %s was not found in Launchpad.' % (src_package,
                previous_version))
        if not launchpad.is_valid_source_version(src_package, new_version):
            raise NotFound('%s version %s was not found in Launchpad.' % (src_package,
                new_version))

However, if you provide an invalid package version like in the following url the json content does not include the version not found in Launchpad message. However, you do receive a 404 response.

 $ curl -v https://errors.ubuntu.com/api/1.0/package-version-new-buckets/\?format\=json\&package\=xdiagnose\&previous_version\=3.2.2\&new_version\=0.1.1

…

< HTTP/1.1 404 NOT FOUND
< Date: Thu, 20 Jun 2013 15:12:03 GMT
< Server: Apache/2.2.22 (Ubuntu)
< Vary: Cookie
< X-Daisy-Revision-Number: 370
< X-Errors-Revision-Number: 438
< Content-Length: 92
< Content-Type: application/json; charset=utf-8
< Strict-Transport-Security: max-age=2592000
<
{
  "error_message": "Sorry, this request could not be processed. Please try again later."
* Connection #0 to host errors.ubuntu.com left intact
}%

[Evan (ev)]

It will if you set settings.DEBUG = True, but we don't have that enabled in production. Tastypie does let you override the default error message (settings.TASTYPIE_CANNED_ERROR), but that's global.

I think the cleaner solution would be to override _handle_500 and checking to see if `exception` is an instance of NOT_FOUND_EXCEPTIONS (see tastypie/resources.py:277). If it isn't, call the parent _handle_500. If it is, return self.error_response(request, {'error_message': 'your error goes here'}, response_class=HttpResponseNotFound).