我正在调试另一个程序员编写的代码，该程序员使用django-piston提供一个API，通过JSON将Python字典对象返回给调用者。我正在关注活塞here的文档。
我注意到一些奇怪的行为，如果我手动设置response = rc.CREATED和response.content = my_dict，那么即使我尝试用{{1 }}
以下是一些示例代码。
response['Content-Type'] = 'application/json; charset=utf-8'使用Wireshark，我看到read（）正确返回JSON。
class RequestHandler(BaseHandler):
'''API handler for translation request queries.'''
# we don't allow updating translation requests
allowed_methods = ('GET', 'POST', 'DELETE')
@throttle(MAX_REQUESTS_PER_MINUTE, 60)
def read(self, request, shortname = None, results = False):
'''Handles a GET request asking about translation requests.'''
not_deleted = TranslationRequest.objects.exclude(deleted = True)
not_deleted = not_deleted.filter(owner = request.user)
if shortname is None:
objects = not_deleted.all()
else:
try:
_request_uuid = uuid.UUID(shortname)
objects = [get_object_or_404(not_deleted, request_id=shortname)]
except ValueError:
objects = [get_object_or_404(not_deleted, shortname=shortname)]
objects = [ RequestHandler.request_to_dict(o, results)
for o in objects ]
if len(objects) == 1:
objects = objects[0]
return objects
@throttle(MAX_REQUESTS_PER_MINUTE, 60)
def create(self, request, shortname = None, results = False):
'''Handles a POST request to create a new translation request.'''
if shortname is not None or results:
return rc.BAD_REQUEST
print 'CREATE content-type', request.content_type # DEBUG
# get the data from the POST request
postdata = self.flatten_dict(request.POST)
# ensure that the worker field is present
postdata['worker'] = postdata.get('worker','')
# validate POST data using our Django form
form = TranslationRequestForm(request.user, postdata, request.FILES)
try:
if not form.is_valid():
return rc.BAD_REQUEST
except KeyError:
return rc.BAD_REQUEST
# create a new request object
new = TranslationRequest()
new.shortname = form.cleaned_data['shortname']
new.owner = request.user
new.worker = form.cleaned_data['worker']
# create a new worker message
message = TranslationRequestMessage()
message.request_id = new.request_id
message.source_language = form.cleaned_data['source_language']
message.target_language = form.cleaned_data['target_language']
message.source_text = u''
for chunk in request.FILES['source_text'].chunks():
message.source_text += unicode(chunk, 'utf-8')
handle = open('{0}/{1}.message'.format(TRANSLATION_MESSAGE_PATH,
new.request_id), 'w+b')
handle.write(message.SerializeToString())
handle.close()
new.save()
new.start_translation()
messages.add_message(request, messages.SUCCESS, 'Successfully ' \
'started translation request "{0}".'.format(
new.shortname))
# return 201 CREATED
response = rc.CREATED
# put the URI of the newly created object into the HTTP header
# Location field (see RFC 2616)
response['Content-Type'] = 'application/json; charset=utf-8'
response['Location'] = reverse('requests', args=[new.request_id + '/'])
# echo the created object inside the HTTP response
# NOTE: this overwrites the "Location" header field set above.
# See piston.resource.__call__()
response.content = RequestHandler.request_to_dict(new, include_results=False)
return response
@staticmethod
def request_to_dict ( request, include_results = False ):
'''Transforms a TranslationRequest object to a Python
dictionary.'''
retval = {}
retval['owner'] = request.owner.username
retval['shortname'] = request.shortname
retval['worker'] = request.worker.shortname
retval['created'] = request.created
retval['request_id'] = request.request_id
retval['ready'] = request.is_ready()
if include_results:
translation_message = request.fetch_translation()
if type(translation_message) == TranslationRequestMessage:
retval['source_language'] = translation_message.source_language
retval['target_language'] = translation_message.target_language
retval['result'] = translation_message.target_text
retval.update( [(x.key, x.value) for x in
translation_message.packet_data] )
else:
retval['result'] = translation_message
return retval
但是，当我尝试使用create（）时，我得到以下响应：
HTTP/1.0 201 CREATED
Date: Thu, 30 Dec 2010 18:40:25 GMT
Server: WSGIServer/0.1 Python/2.6.6
Vary: Authorization, Cookie
Content-Type: text/plain
Location: http://localhost:8081/mt-serverland/dashboard/api/requests/6614acd8491e4034bcb9b6a9430e6947/
Set-Cookie: sessionid=5536e58e88ded4365b536a354d3b8a7d; expires=Thu, 13-Jan-2011 18:40:25 GMT; Max-Age=1209600; Path=/
{'created': datetime.datetime(2010, 12, 30, 19, 40, 25, 282665), 'worker': u'GoogleWorker', 'ready': False, 'request_id': '6614acd8491e4034bcb9b6a9430e6947', 'owner': u'admin', 'shortname': u'1234567'}
如果我修改create（）只返回GET /mt-serverland/dashboard/api/results/?token=7594f0db HTTP/1.1
Host: localhost:8081
Accept-Encoding: identity
HTTP/1.0 200 OK
Date: Sat, 01 Jan 2011 01:05:36 GMT
Server: WSGIServer/0.1 Python/2.6.6
Vary: Authorization
Content-Type: application/json; charset=utf-8
[
{
"created": "2010-12-31 17:47:51",
"source_language": "eng",
"worker": "GoogleWorker",
"owner": "admin",
"result": "Esta es una prueba.\nEspero que este archivo se traducirá correctamente.",
"request_id": "b4ca75a301714a5097ce4daab35d370b",
"ready": true,
"shortname": "test01",
"target_language": "spa"
}
]
返回的对象，那么响应内容为RequestHandler.request_to_dict()。任何想法为什么会这样？谢谢！
答案 0 :(得分：2)
我遇到了一个非常类似的问题。在通过Piston和Django源码挖掘之后，我决定尝试这个并且它有效：
resp = rc.CREATED
resp.content = dict(
attendee_id=attendee.id,
order_id=order.id,
)
return resp
这会在HTTP中产生这一点（为简洁起见，删除了一些标题）。
< HTTP/1.1 201 CREATED
< Date: Thu, 27 Jan 2011 16:59:38 GMT
< Server: WSGIServer/0.1 Python/2.6.5
< Vary: Authorization
< Content-Type: application/json; charset=utf-8
< Transfer-Encoding: chunked
<
{
"order_id": 22446505,
"attendee_id": 18
}