django-rest-framework/djangorestframework/parsers.py
2011-03-04 12:28:20 +02:00

140 lines
4.5 KiB
Python

from StringIO import StringIO
from django.http.multipartparser import MultiPartParser as DjangoMPParser
from djangorestframework.response import ResponseException
from djangorestframework import status
try:
import json
except ImportError:
import simplejson as json
try:
from urlparse import parse_qs
except ImportError:
from cgi import parse_qs
class ParserMixin(object):
parsers = ()
def parse(self, content_type, content):
# See RFC 2616 sec 3 - http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7
split = content_type.split(';', 1)
if len(split) > 1:
content_type = split[0]
content_type = content_type.strip()
media_type_to_parser = dict([(parser.media_type, parser) for parser in self.parsers])
try:
parser = media_type_to_parser[content_type]
except KeyError:
raise ResponseException(status.HTTP_415_UNSUPPORTED_MEDIA_TYPE,
{'error': 'Unsupported media type in request \'%s\'.' % content_type})
return parser(self).parse(content)
@property
def parsed_media_types(self):
"""Return an list of all the media types that this ParserMixin can parse."""
return [parser.media_type for parser in self.parsers]
@property
def default_parser(self):
"""Return the ParerMixin's most prefered emitter.
(This has no behavioural effect, but is may be used by documenting emitters)"""
return self.parsers[0]
class BaseParser(object):
"""All parsers should extend BaseParser, specifing a media_type attribute,
and overriding the parse() method."""
media_type = None
def __init__(self, resource):
"""Initialise the parser with the Resource instance as state,
in case the parser needs to access any metadata on the Resource object."""
self.resource = resource
def parse(self, input):
"""Given some serialized input, return the deserialized output.
The input will be the raw request content body. The return value may be of
any type, but for many parsers/inputs it might typically be a dict."""
return input
class JSONParser(BaseParser):
media_type = 'application/json'
def parse(self, input):
try:
return json.loads(input)
except ValueError, exc:
raise ResponseException(status.HTTP_400_BAD_REQUEST, {'detail': 'JSON parse error - %s' % str(exc)})
class XMLParser(BaseParser):
media_type = 'application/xml'
class FormParser(BaseParser):
"""The default parser for form data.
Return a dict containing a single value for each non-reserved parameter.
"""
# TODO: not good, because posted/put lists are flattened !!!
media_type = 'application/x-www-form-urlencoded'
def parse(self, input):
request = self.resource.request
if request.method == 'PUT':
data = parse_qs(input)
# Flattening the parsed query data
for key, val in data.items():
data[key] = val[0]
if request.method == 'POST':
# Django has already done the form parsing for us.
data = dict(request.POST.items())
# Strip any parameters that we are treating as reserved
for key in data:
if key in self.resource.RESERVED_FORM_PARAMS:
data.pop(key)
return data
# TODO: Allow parsers to specify multiple media_types
class MultipartParser(FormParser):
media_type = 'multipart/form-data'
def parse(self, input):
request = self.resource.request
if request.method == 'PUT':
upload_handlers = request._get_upload_handlers()
django_mpp = DjangoMPParser(request.META, StringIO(input), upload_handlers)
data, files = django_mpp.parse()
data = dict(data)
files = dict(files)
if request.method == 'POST':
# Django has already done the form parsing for us.
data = dict(request.POST)
files = dict(request.FILES)
# Flattening, then merging the POSTED/PUT data/files
for key, val in dict(data).items():
data[key] = val[0]
for key, val in dict(files).items():
files[key] = val[0].read()
data.update(files)
# Strip any parameters that we are treating as reserved
for key in data:
if key in self.resource.RESERVED_FORM_PARAMS:
data.pop(key)
return data