Renderers can now cope with parameterised args. ResponseMixin gets cleaned up &…

Renderers can now cope with parameterised args.  ResponseMixin gets cleaned up & added Renderer.can_handle_response(), mirroring Parsers.can_handle_request()

djangorestframework/mixins.py

@@ -14,7 +14,7 @@ from djangorestframework.parsers import FormParser, MultiPartParser
 from djangorestframework.resources import Resource
 from djangorestframework.response import Response, ErrorResponse
 from djangorestframework.utils import as_tuple, MSIE_USER_AGENT_REGEX
-from djangorestframework.utils.mediatypes import is_form_media_type
+from djangorestframework.utils.mediatypes import is_form_media_type, order_by_precedence
 
 from decimal import Decimal
 import re
@@ -206,7 +206,7 @@ class RequestMixin(object):
     @property
     def _default_parser(self):
         """
-        Return the view's default parser.
+        Return the view's default parser class.
         """        
         return self.parsers[0]
 
@@ -245,15 +245,15 @@ class ResponseMixin(object):
         try:
             renderer = self._determine_renderer(self.request)
         except ErrorResponse, exc:
-            renderer = self._default_renderer
+            renderer = self._default_renderer(self)
             response = exc.response
         
         # Serialize the response content
         # TODO: renderer.media_type isn't the right thing to do here...
         if response.has_content_body:
-            content = renderer(self).render(response.cleaned_content, renderer.media_type)
+            content = renderer.render(response.cleaned_content, renderer.media_type)
         else:
-            content = renderer(self).render()
+            content = renderer.render()
 
         # Build the HTTP Response
         # TODO: renderer.media_type isn't the right thing to do here...
@@ -264,10 +264,6 @@ class ResponseMixin(object):
         return resp
 
 
-    # TODO: This should be simpler now.
-    #       Add a handles_response() to the renderer, then iterate through the
-    #       acceptable media types, ordered by how specific they are,
-    #       calling handles_response on each renderer.
     def _determine_renderer(self, request):
         """
         Return the appropriate renderer for the output, given the client's 'Accept' header,
@@ -282,60 +278,33 @@ class ResponseMixin(object):
         elif (self._IGNORE_IE_ACCEPT_HEADER and
               request.META.has_key('HTTP_USER_AGENT') and
               MSIE_USER_AGENT_REGEX.match(request.META['HTTP_USER_AGENT'])):
+            # Ignore MSIE's broken accept behavior and do something sensible instead
             accept_list = ['text/html', '*/*']
         elif request.META.has_key('HTTP_ACCEPT'):
             # Use standard HTTP Accept negotiation
-            accept_list = request.META["HTTP_ACCEPT"].split(',')
+            accept_list = [token.strip() for token in request.META["HTTP_ACCEPT"].split(',')]
         else:
             # No accept header specified
-            return self._default_renderer
-        
-        # 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)]
+            return self._default_renderer(self)
+
+        # Check the acceptable media types against each renderer,
+        # attempting more specific media types first
+        # NB. The inner loop here isn't as bad as it first looks :)
+        #     We're effectivly looping over max len(accept_list) * len(self.renderers)
+        renderers = [renderer_cls(self) for renderer_cls in self.renderers]
+
+        for media_type_lst in order_by_precedence(accept_list):
+            for renderer in renderers:
+                for media_type in media_type_lst:
+                    if renderer.can_handle_response(media_type):
+                        return renderer
        
-        for accept_set in accept_sets:
-            # Return any exact match
-            for renderer in self.renderers:
-                if renderer.media_type in accept_set:
-                    return renderer
-
-            # Return any subtype match
-            for renderer in self.renderers:
-                if renderer.media_type.split('/')[0] + '/*' in accept_set:
-                    return renderer
-
-            # Return default
-            if '*/*' in accept_set:
-                return self._default_renderer
-      
-
+        # No acceptable renderers were found
         raise ErrorResponse(status.HTTP_406_NOT_ACCEPTABLE,
                                 {'detail': 'Could not satisfy the client\'s Accept header',
                                  'available_types': self._rendered_media_types})
 
+
     @property
     def _rendered_media_types(self):
         """
@@ -346,7 +315,7 @@ class ResponseMixin(object):
     @property
     def _default_renderer(self):
         """
-        Return the view's default renderer.
+        Return the view's default renderer class.
         """
         return self.renderers[0]
 

djangorestframework/parsers.py

@@ -54,7 +54,7 @@ class BaseParser(object):
         This may be overridden to provide for other behavior, but typically you'll
         instead want to just set the :attr:`media_type` attribute on the class.
         """
-        return media_type_matches(content_type, self.media_type)
+        return media_type_matches(self.media_type, content_type)
 
     def parse(self, stream):
         """

djangorestframework/renderers.py

@@ -16,7 +16,7 @@ from djangorestframework.compat import apply_markdown
 from djangorestframework.utils import dict2xml, url_resolves
 from djangorestframework.utils.breadcrumbs import get_breadcrumbs
 from djangorestframework.utils.description import get_name, get_description
-from djangorestframework.utils.mediatypes import get_media_type_params, add_media_type_param
+from djangorestframework.utils.mediatypes import get_media_type_params, add_media_type_param, media_type_matches
 
 from decimal import Decimal
 import re
@@ -39,11 +39,26 @@ class BaseRenderer(object):
     All renderers must extend this class, set the :attr:`media_type` attribute,
     and override the :meth:`render` method.
     """
+
     media_type = None
 
     def __init__(self, view):
         self.view = view
 
+    def can_handle_response(self, accept):
+        """
+        Returns :const:`True` if this renderer is able to deal with the given
+        *accept* media type.
+
+        The default implementation for this function is to check the *accept*
+        argument against the :attr:`media_type` attribute set on the class to see if
+        they match.
+
+        This may be overridden to provide for other behavior, but typically you'll
+        instead want to just set the :attr:`media_type` attribute on the class.
+        """
+        return media_type_matches(self.media_type, accept)
+
     def render(self, obj=None, media_type=None):
         """
         Given an object render it into a string.
@@ -66,9 +81,13 @@ class JSONRenderer(BaseRenderer):
     """
     Renderer which serializes to JSON
     """
+
     media_type = 'application/json'
 
     def render(self, obj=None, media_type=None):
+        """
+        Renders *obj* into serialized JSON.
+        """
         if obj is None:
             return ''
 
@@ -92,6 +111,9 @@ class XMLRenderer(BaseRenderer):
     media_type = 'application/xml'
 
     def render(self, obj=None, media_type=None):
+        """
+        Renders *obj* into serialized XML.
+        """
         if obj is None:
             return ''
         return dict2xml(obj)
@@ -103,17 +125,22 @@ class TemplateRenderer(BaseRenderer):
 
     Render the object simply by using the given template.
     To create a template renderer, subclass this class, and set
-    the :attr:`media_type` and `:attr:template` attributes.
+    the :attr:`media_type` and :attr:`template` attributes.
     """
+
     media_type = None
     template = None
 
     def render(self, obj=None, media_type=None):
+        """
+        Renders *obj* using the :attr:`template` specified on the class.
+        """
         if obj is None:
             return ''
 
-        context = RequestContext(self.request, obj)
-        return self.template.render(context)
+        template = loader.get_template(self.template)
+        context = RequestContext(self.view.request, {'object': obj})
+        return template.render(context)
 
 
 class DocumentingTemplateRenderer(BaseRenderer):
@@ -121,6 +148,7 @@ class DocumentingTemplateRenderer(BaseRenderer):
     Base class for renderers used to self-document the API.
     Implementing classes should extend this class and set the template attribute.
     """
+
     template = None
 
     def _get_content(self, view, request, obj, media_type):
@@ -215,6 +243,12 @@ class DocumentingTemplateRenderer(BaseRenderer):
 
 
     def render(self, obj=None, media_type=None):
+        """
+        Renders *obj* using the :attr:`template` set on the class.
+
+        The context used in the template contains all the information
+        needed to self-document the response to this request.
+        """
         content = self._get_content(self.view, self.view.request, obj, media_type)
         form_instance = self._get_form_instance(self.view)
 
@@ -272,6 +306,7 @@ class DocumentingHTMLRenderer(DocumentingTemplateRenderer):
     Renderer which provides a browsable HTML interface for an API.
     See the examples at http://api.django-rest-framework.org to see this in action.
     """
+
     media_type = 'text/html'
     template = 'renderer.html'
 
@@ -282,6 +317,7 @@ class DocumentingXHTMLRenderer(DocumentingTemplateRenderer):
     We need this to be listed in preference to xml in order to return HTML to WebKit based browsers,
     given their Accept headers.
     """
+
     media_type = 'application/xhtml+xml'
     template = 'renderer.html'
 
@@ -292,6 +328,7 @@ class DocumentingPlainTextRenderer(DocumentingTemplateRenderer):
     documentation of the returned status and headers, and of the resource's name and description.
     Useful for browsing an API with command line tools.
     """
+
     media_type = 'text/plain'
     template = 'renderer.txt'
 

djangorestframework/templatetags/add_query_param.py

@@ -4,7 +4,7 @@ from urllib import quote
 register = Library()
 
 def add_query_param(url, param):
-    (key, val) = param.split('=')
+    (key, sep, val) = param.partition('=')
     param = '%s=%s' % (key, quote(val))
     (scheme, netloc, path, params, query, fragment) = urlparse(url)
     if query:

djangorestframework/tests/renderers.py

@@ -13,23 +13,24 @@ DUMMYCONTENT = 'dummycontent'
 RENDERER_A_SERIALIZER = lambda x: 'Renderer A: %s' % x
 RENDERER_B_SERIALIZER = lambda x: 'Renderer B: %s' % x
 
-class MockView(ResponseMixin, DjangoView):
-    def get(self, request):
-        response = Response(DUMMYSTATUS, DUMMYCONTENT)
-        return self.render(response)
-
 class RendererA(BaseRenderer):
     media_type = 'mock/renderera'
 
-    def render(self, obj=None, content_type=None):
+    def render(self, obj=None, media_type=None):
         return RENDERER_A_SERIALIZER(obj)
 
 class RendererB(BaseRenderer):
     media_type = 'mock/rendererb'
 
-    def render(self, obj=None, content_type=None):
+    def render(self, obj=None, media_type=None):
         return RENDERER_B_SERIALIZER(obj)
 
+class MockView(ResponseMixin, DjangoView):
+    renderers = (RendererA, RendererB)
+
+    def get(self, request):
+        response = Response(DUMMYSTATUS, DUMMYCONTENT)
+        return self.render(response)
 
 urlpatterns = patterns('',
     url(r'^$', MockView.as_view(renderers=[RendererA, RendererB])),

djangorestframework/utils/__init__.py

@@ -13,6 +13,9 @@ import xml.etree.ElementTree as ET
 #    """Adds the ADMIN_MEDIA_PREFIX to the request context."""
 #    return {'ADMIN_MEDIA_PREFIX': settings.ADMIN_MEDIA_PREFIX}
 
+from mediatypes import media_type_matches, is_form_media_type
+from mediatypes import add_media_type_param, get_media_type_params, order_by_precedence
+
 MSIE_USER_AGENT_REGEX = re.compile(r'^Mozilla/[0-9]+\.[0-9]+ \([^)]*; MSIE [0-9]+\.[0-9]+[a-z]?;[^)]*\)(?!.* Opera )')
 
 def as_tuple(obj):

djangorestframework/utils/mediatypes.py

@@ -51,6 +51,22 @@ def get_media_type_params(media_type):
     return _MediaType(media_type).params
 
 
+def order_by_precedence(media_type_lst):
+    """
+    Returns a list of lists of media type strings, ordered by precedence.
+    Precedence is determined by how specific a media type is:
+
+    3. 'type/subtype; param=val'
+    2. 'type/subtype'
+    1. 'type/*'
+    0. '*/*'
+    """
+    ret = [[],[],[],[]]
+    for media_type in media_type_lst:
+        precedence = _MediaType(media_type).precedence
+        ret[3-precedence].append(media_type)
+    return ret
+
 
 class _MediaType(object):
     def __init__(self, media_type_str):
@@ -61,53 +77,54 @@ class _MediaType(object):
         self.main_type, sep, self.sub_type = self.full_type.partition('/')
 
     def match(self, other):
-        """Return true if this MediaType satisfies the constraint of the given MediaType."""
-        for key in other.params.keys():
-            if key != 'q' and other.params[key] != self.params.get(key, None):
+        """Return true if this MediaType satisfies the given MediaType."""
+        for key in self.params.keys():
+            if key != 'q' and other.params.get(key, None) != self.params.get(key, None):
                 return False
 
-        if other.sub_type != '*' and other.sub_type != self.sub_type:
+        if self.sub_type != '*' and other.sub_type != '*'  and other.sub_type != self.sub_type:
             return False
 
-        if other.main_type != '*' and other.main_type != self.main_type:
+        if self.main_type != '*' and other.main_type != '*' and other.main_type != self.main_type:
             return False
 
         return True
 
+    @property
     def precedence(self):
         """
-        Return a precedence level for the media type given how specific it is.
+        Return a precedence level from 0-3 for the media type given how specific it is.
         """
         if self.main_type == '*':
-            return 1
+            return 0
         elif self.sub_type == '*':
-            return 2
+            return 1
         elif not self.params or self.params.keys() == ['q']:
-            return 3
-        return 4
-
-    def quality(self):
-        """
-        Return a quality level for the media type.
-        """
-        try:
-            return Decimal(self.params.get('q', '1.0'))
-        except:
-            return Decimal(0)
-    
-    def score(self):
-        """
-        Return an overall score for a given media type given it's quality and precedence.
-        """
-        # NB. quality values should only have up to 3 decimal points
-        # http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.9
-        return self.quality * 10000 + self.precedence
+            return 2
+        return 3
+
+    #def quality(self):
+    #    """
+    #    Return a quality level for the media type.
+    #    """
+    #    try:
+    #        return Decimal(self.params.get('q', '1.0'))
+    #    except:
+    #        return Decimal(0)
+ 
+    #def score(self):
+    #    """
+    #    Return an overall score for a given media type given it's quality and precedence.
+    #    """
+    #    # NB. quality values should only have up to 3 decimal points
+    #    # http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.9
+    #    return self.quality * 10000 + self.precedence
     
-    def as_tuple(self):
-        return (self.main_type, self.sub_type, self.params)
+    #def as_tuple(self):
+    #    return (self.main_type, self.sub_type, self.params)
 
-    def __repr__(self):
-        return "<MediaType %s>" % (self.as_tuple(),)
+    #def __repr__(self):
+    #    return "<MediaType %s>" % (self.as_tuple(),)
 
     def __str__(self):
         return unicode(self).encode('utf-8')

djangorestframework/views.py

@@ -99,52 +99,58 @@ class View(ResourceMixin, RequestMixin, ResponseMixin, AuthMixin, DjangoView):
     # all other authentication is CSRF exempt.
     @csrf_exempt
     def dispatch(self, request, *args, **kwargs):
-        self.request = request
-        self.args = args
-        self.kwargs = kwargs
-
-        # Calls to 'reverse' will not be fully qualified unless we set the scheme/host/port here.
-        prefix = '%s://%s' % (request.is_secure() and 'https' or 'http', request.get_host())
-        set_script_prefix(prefix)
-
         try:
-            self.initial(request, *args, **kwargs)
-
-            # Authenticate and check request has the relevant permissions
-            self._check_permissions()
-
-            # Get the appropriate handler method
-            if self.method.lower() in self.http_method_names:
-                handler = getattr(self, self.method.lower(), self.http_method_not_allowed)
-            else:
-                handler = self.http_method_not_allowed
-
-            response_obj = handler(request, *args, **kwargs)
-
-            # Allow return value to be either HttpResponse, Response, or an object, or None
-            if isinstance(response_obj, HttpResponse):
-                return response_obj
-            elif isinstance(response_obj, Response):
-                response = response_obj
-            elif response_obj is not None:
-                response = Response(status.HTTP_200_OK, response_obj)
-            else:
-                response = Response(status.HTTP_204_NO_CONTENT)
-
-            # Pre-serialize filtering (eg filter complex objects into natively serializable types)
-            response.cleaned_content = self.filter_response(response.raw_content)
+            self.request = request
+            self.args = args
+            self.kwargs = kwargs
     
-        except ErrorResponse, exc:
-            response = exc.response
-
-        # Always add these headers.
-        #
-        # TODO - this isn't actually the correct way to set the vary header,
-        # also it's currently sub-obtimal for HTTP caching - need to sort that out. 
-        response.headers['Allow'] = ', '.join(self.allowed_methods)
-        response.headers['Vary'] = 'Authenticate, Accept'
-
-        return self.render(response)
+            # Calls to 'reverse' will not be fully qualified unless we set the scheme/host/port here.
+            prefix = '%s://%s' % (request.is_secure() and 'https' or 'http', request.get_host())
+            set_script_prefix(prefix)
+    
+            try:
+                self.initial(request, *args, **kwargs)
+    
+                # Authenticate and check request has the relevant permissions
+                self._check_permissions()
+    
+                # Get the appropriate handler method
+                if self.method.lower() in self.http_method_names:
+                    handler = getattr(self, self.method.lower(), self.http_method_not_allowed)
+                else:
+                    handler = self.http_method_not_allowed
+    
+                response_obj = handler(request, *args, **kwargs)
+    
+                # Allow return value to be either HttpResponse, Response, or an object, or None
+                if isinstance(response_obj, HttpResponse):
+                    return response_obj
+                elif isinstance(response_obj, Response):
+                    response = response_obj
+                elif response_obj is not None:
+                    response = Response(status.HTTP_200_OK, response_obj)
+                else:
+                    response = Response(status.HTTP_204_NO_CONTENT)
+    
+                # Pre-serialize filtering (eg filter complex objects into natively serializable types)
+                response.cleaned_content = self.filter_response(response.raw_content)
+        
+            except ErrorResponse, exc:
+                response = exc.response
+    
+            # Always add these headers.
+            #
+            # TODO - this isn't actually the correct way to set the vary header,
+            # also it's currently sub-obtimal for HTTP caching - need to sort that out. 
+            response.headers['Allow'] = ', '.join(self.allowed_methods)
+            response.headers['Vary'] = 'Authenticate, Accept'
+    
+            return self.render(response)
+                    
+        except:
+            import traceback
+            traceback.print_exc()
+            raise