  except ImportError:
      import simplejson as json
  
  
  _MSIE_USER_AGENT = re.compile(r'^Mozilla/[0-9]+\.[0-9]+ \([^)]*; MSIE [0-9]+\.[0-9]+[a-z]?;[^)]*\)(?!.* Opera )')
  
  
  class EmitterMixin(object):
      """Adds behaviour for pluggable Emitters to a :class:`.Resource` or Django :class:`View`. class.
      
      Default behaviour is to use standard HTTP Accept header content negotiation.
      Also supports overidding the content type by specifying an _accept= parameter in the URL.
      Ignores Accept headers from Internet Explorer user agents and uses a sensible browser Accept header instead."""
  
      ACCEPT_QUERY_PARAM = '_accept'        # Allow override of Accept header in URL query params
      REWRITE_IE_ACCEPT_HEADER = True
  
      request = None
      response = None
      emitters = ()
  
      def emit(self, response):
          """Takes a :class:`Response` object and returns a Django :class:`HttpResponse`."""
          self.response = response
  
          try:
              emitter = self._determine_emitter(self.request)
          except ResponseException, exc:
              emitter = self.default_emitter
              response = exc.response
          
          # Serialize the response content
          if response.has_content_body:
              content = emitter(self).emit(output=response.cleaned_content)
          else:
              content = emitter(self).emit()
          
          # Munge DELETE Response code to allow us to return content
          # (Do this *after* we've rendered the template so that we include the normal deletion response code in the output)
          if response.status == 204:
              response.status = 200
          
          # Build the HTTP Response
          # TODO: Check if emitter.mimetype is underspecified, or if a content-type header has been set
          resp = HttpResponse(content, mimetype=emitter.media_type, status=response.status)
          for (key, val) in response.headers.items():
              resp[key] = val
  
          return resp
  
  
      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"""
  
          if self.ACCEPT_QUERY_PARAM and request.GET.get(self.ACCEPT_QUERY_PARAM, None):
              # Use _accept parameter override
              accept_list = [request.GET.get(self.ACCEPT_QUERY_PARAM)]
          elif self.REWRITE_IE_ACCEPT_HEADER and request.META.has_key('HTTP_USER_AGENT') and _MSIE_USER_AGENT.match(request.META['HTTP_USER_AGENT']):
              accept_list = ['text/html', '*/*']
          elif request.META.has_key('HTTP_ACCEPT'):
              # Use standard HTTP Accept negotiation
              accept_list = request.META["HTTP_ACCEPT"].split(',')
          else:
              # No accept header specified
              return self.default_emitter
          
          # Parse the accept header into a dict of {qvalue: set of media types}
          # We ignore mietype parameters
          accept_dict = {}    
          for token in accept_list:
              components = token.split(';')
              mimetype = components[0].strip()
              qvalue = Decimal('1.0')
              
              if len(components) > 1:
                  # Parse items that have a qvalue eg text/html;q=0.9
                  try:
                      (q, num) = components[-1].split('=')
                      if q == 'q':
                          qvalue = Decimal(num)
                  except:
                      # Skip malformed entries
                      continue
  
              if accept_dict.has_key(qvalue):
                  accept_dict[qvalue].add(mimetype)
              else:
                  accept_dict[qvalue] = set((mimetype,))
          
          # Convert to a list of sets ordered by qvalue (highest first)
          accept_sets = [accept_dict[qvalue] for qvalue in sorted(accept_dict.keys(), reverse=True)]
         
          for accept_set in accept_sets:
              # Return any exact match
              for emitter in self.emitters:
                  if emitter.media_type in accept_set:
                      return emitter
  
              # Return any subtype match
              for emitter in self.emitters:
                  if emitter.media_type.split('/')[0] + '/*' in accept_set:
                      return emitter
  
              # Return default
              if '*/*' in accept_set:
                  return self.default_emitter
        
  
          raise ResponseException(status.HTTP_406_NOT_ACCEPTABLE,
                                  {'detail': 'Could not statisfy the client\'s Accept header',
                                   'available_types': self.emitted_media_types})
  
      @property
      def emitted_media_types(self):
          """Return an list of all the media types that this resource can emit."""
          return [emitter.media_type for emitter in self.emitters]
  
      @property
      def default_emitter(self):
          """Return the resource's most prefered emitter.
          (This emitter is used if the client does not send and Accept: header, or sends Accept: */*)"""
          return self.emitters[0]
  
  
  
  # TODO: Rename verbose to something more appropriate
  # TODO: NoContent could be handled more cleanly.  It'd be nice if it was handled by default,
  #       and only have an emitter output anything if it explicitly provides support for that.
  
 
</s> remove # TODO: NoContent could be handled more cleanly.  It'd be nice if it was handled by default,
 </s> add # TODO: Maybe None could be handled more cleanly.  It'd be nice if it was handled by default, </s> remove         self.has_content_body = not content is NoContent             # TODO: remove and just use content
        self.raw_content = content      # content prior to filtering - TODO: remove and just use content
        self.cleaned_content = content  # content after filtering      TODO: remove and just use content
 </s> add         self.has_content_body = content is not None
        self.raw_content = content      # content prior to filtering
        self.cleaned_content = content  # content after filtering </s> remove         response.headers['Allow'] = ', '.join(self.allowed_methods)
        response.headers['Vary'] = 'Authenticate, Accept'
 </s> add         try:
            response.headers['Allow'] = ', '.join(self.allowed_methods)
            response.headers['Vary'] = 'Authenticate, Accept' </s> remove     def emit(self, output=NoContent, verbose=False):
        if output is NoContent:
 </s> add     def emit(self, output=None, verbose=False):
        if output is None: </s> remove             raise ResponseException(status.HTTP_404_NOT_FOUND)
 </s> add             raise ErrorResponse(status.HTTP_404_NOT_FOUND)
  except ImportError:
      import simplejson as json
  
  



























































































































  
  # TODO: Rename verbose to something more appropriate
  # TODO: NoContent could be handled more cleanly.  It'd be nice if it was handled by default,
  #       and only have an emitter output anything if it explicitly provides support for that.
  
keep keep keep keep replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace replace keep keep keep keep keep
 Rename mixins into Mixin class, rename ResponseException to ErrorResponse, remove NoContent 
djangorestframework/emitters.py