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Diffstat (limited to 'src/rest/resource.py')
| -rw-r--r-- | src/rest/resource.py | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/src/rest/resource.py b/src/rest/resource.py new file mode 100644 index 00000000..7e4a6cd5 --- /dev/null +++ b/src/rest/resource.py @@ -0,0 +1,113 @@ +from django.http import HttpResponse +from decimal import Decimal +from rest import emitters, parsers + +class Resource(object): + + callmap = { 'GET': 'read', 'POST': 'create', + 'PUT': 'update', 'DELETE': 'delete' } + + emitters = [ ('application/json', emitters.JSONEmitter), + ('text/html', emitters.HTMLEmitter), + ('application/xhtml+xml', emitters.HTMLEmitter), + ('text/plain', emitters.TextEmitter), + ('application/xml', emitters.XMLEmitter), ] + + parsers = { 'application/json': parsers.JSONParser, + 'application/xml': parsers.XMLParser, + 'application/x-www-form-urlencoded': parsers.FormParser } + + def __new__(cls, request, *args, **kwargs): + self = object.__new__(cls) + self.__init__() + return self._handle_request(request, *args, **kwargs) + + def __init__(self): + pass + + def _determine_parser(self, request): + """Return the appropriate parser for the input, given the client's 'Content-Type' header, + and the content types that this Resource knows how to parse.""" + print request.META + return self.parsers.values()[0] + + # TODO: Raise 415 Unsupported media type + + def _determine_emitter(self, request): + """Return the appropriate emitter for the output, given the client's 'Accept' header, + and the content types that this Resource knows how to serve. + + See: RFC 2616, Section 14 - http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html + """ + + default = self.emitters[0] + + if not request.META.has_key('HTTP_ACCEPT'): + return default + + # Parse the accept header into a dict of {Priority: List of Mimetypes} + accept_list = [item.split(';') for item in request.META["HTTP_ACCEPT"].split(',')] + accept_dict = {} + for item in accept_list: + mimetype = item[0].strip() + qvalue = Decimal('1.0') + + if len(item) > 1: + # Parse items that have a qvalue eg text/html;q=0.9 + try: + (q, num) = item[1].split('=') + if q == 'q': + qvalue = Decimal(num) + except: + # Skip malformed entries + continue + + if accept_dict.has_key(qvalue): + accept_dict[qvalue].append(mimetype) + else: + accept_dict[qvalue] = [mimetype] + + # Go through all accepted mimetypes in priority order and return our first match + qvalues = accept_dict.keys() + qvalues.sort(reverse=True) + + for qvalue in qvalues: + for (mimetype, emitter) in self.emitters: + for accept_mimetype in accept_dict[qvalue]: + if ((accept_mimetype == '*/*') or + (accept_mimetype.endswith('/*') and mimetype.startswith(accept_mimetype[:-1])) or + (accept_mimetype == mimetype)): + return (mimetype, emitter) + + # TODO: Raise 406, Not Acceptable + + def _handle_request(self, request, *args, **kwargs): + meth = request.method + + # Parse the HTTP Request content + if meth in ('PUT', 'POST'): + parser = self._determine_parser(request) + data = parser(self, request).parse(request.raw_post_data) + + if meth == "POST": + (status, ret, headers) = self.handle_post(data, request.META, *args, **kwargs) + else: + (status, ret, headers) = self.handle_get(request.META, *args, **kwargs) + + # Serialize the HTTP Response content + mimetype, emitter = self._determine_emitter(request) + content = emitter(self, status, headers).emit(ret) + print mimetype, emitter, content + + # Build the HTTP Response + resp = HttpResponse(content, mimetype=mimetype, status=status) + for (key, val) in headers.items(): + resp[key] = val + + return resp + + def handle_get(self): + raise NotImplementedError(self.handle_get) + + def handle_post(self): + raise NotImplementedError(self.handle_post)
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