Index: django/views/decorators/http.py =================================================================== --- django/views/decorators/http.py (revision 6551) +++ django/views/decorators/http.py (working copy) @@ -2,9 +2,12 @@ Decorators for views based on HTTP headers. """ +from calendar import timegm +from datetime import timedelta +from email.Utils import formatdate from django.utils.decorators import decorator_from_middleware from django.middleware.http import ConditionalGetMiddleware -from django.http import HttpResponseNotAllowed +from django.http import HttpResponseNotAllowed, HttpResponseNotModified conditional_page = decorator_from_middleware(ConditionalGetMiddleware) @@ -31,4 +34,67 @@ require_GET.__doc__ = "Decorator to require that a view only accept the GET method." require_POST = require_http_methods(["POST"]) -require_POST.__doc__ = "Decorator to require that a view only accept the POST method." \ No newline at end of file +require_POST.__doc__ = "Decorator to require that a view only accept the POST method." + + +def _none(*args, **kwargs): + return None + +def condition(last_modified=_none, etag=_none): + """ + Decorator to support conditional get for a view. It takes as parameters + user-defined functions that calculate etag and/or last modified time. + + Both functions are passed the same parameters as the view itself. "last_modified@ + should return a standard datetime value and "etag" should return a string. + + Usage with last_modified:: + + @condition(lambda r, obj_id: MyObject.objects.get(pk=obj_id).update_time) + def my_object_view(request, obj_id): + # ... + + You can pass last_modified, etag or both of them (if you really need it). + """ + def decorator(func): + def inner(request, *args, **kwargs): + + # _call_* functions are used to format and memoize output from user supplied callables + def _call_last_modified(): + result = [] + def caller(): + if not result: + dt = last_modified(request, *args, **kwargs) + result.append(dt and (formatdate(timegm(dt.utctimetuple()))[:26] + 'GMT')) + return result[0] + return caller + _last_modified = _call_last_modified() + + def _call_etag(): + result = [] + def caller(): + if not result: + result.append(etag(request, *args, **kwargs)) + return result[0] + return caller + _etag = _call_etag() + + if request.method not in ('GET', 'HEAD'): + return func(request, *args, **kwargs) + if_modified_since = request.META.get('HTTP_IF_MODIFIED_SINCE', None) + if_none_match = request.META.get('HTTP_IF_NONE_MATCH', None) + if if_none_match: + if_none_match = [e.strip() for e in if_none_match.split(',')] + not_modified = (if_modified_since or if_none_match) and \ + (not if_modified_since or _last_modified() == if_modified_since) and \ + (not if_none_match or _etag() in if_none_match) + if not_modified: + return HttpResponseNotModified() + response = func(request, *args, **kwargs) + if _last_modified() and not response.has_header('Last-Modified'): + response['Last-Modified'] = _last_modified() + if _etag() and not response.has_header('ETag'): + response['ETag'] = _etag() + return response + return inner + return decorator \ No newline at end of file Index: tests/regressiontests/conditional_get/views.py =================================================================== --- tests/regressiontests/conditional_get/views.py (revision 0) +++ tests/regressiontests/conditional_get/views.py (revision 0) @@ -0,0 +1,17 @@ +# -*- coding:utf-8 -*- +from django.views.decorators.http import condition +from django.http import HttpResponse + +from models import FULL_RESPONSE, LAST_MODIFIED, ETAG + +@condition(lambda r: LAST_MODIFIED, lambda r: ETAG) +def index(request): + return HttpResponse(FULL_RESPONSE) + +@condition(last_modified=lambda r: LAST_MODIFIED) +def last_modified(request): + return HttpResponse(FULL_RESPONSE) + +@condition(etag=lambda r: ETAG) +def etag(request): + return HttpResponse(FULL_RESPONSE) \ No newline at end of file Index: tests/regressiontests/conditional_get/__init__.py =================================================================== Index: tests/regressiontests/conditional_get/models.py =================================================================== --- tests/regressiontests/conditional_get/models.py (revision 0) +++ tests/regressiontests/conditional_get/models.py (revision 0) @@ -0,0 +1,84 @@ +# -*- coding:utf-8 -*- +from datetime import datetime, timedelta +from calendar import timegm +from django.test import TestCase + +FULL_RESPONSE = 'Test conditional get response' +LAST_MODIFIED = datetime(2007, 10, 21, 23, 21, 47) +LAST_MODIFIED_STR = 'Sun, 21 Oct 2007 23:21:47 GMT' +EXPIRED_LAST_MODIFIED_STR = 'Sat, 20 Oct 2007 23:21:47 GMT' +ETAG = '"b4246ffc4f62314ca13147c9d4f76974"' +EXPIRED_ETAG = '"7fae4cd4b0f81e7d2914700043aa8ed6"' + +class ConditionalGet(TestCase): + def assertFullResponse(self, response, check_last_modified=True, check_etag=True): + self.assertEquals(response.status_code, 200) + self.assertEquals(response.content, FULL_RESPONSE) + if check_last_modified: + self.assertEquals(response['Last-Modified'], LAST_MODIFIED_STR) + if check_etag: + self.assertEquals(response['ETag'], ETAG) + + def assertNotModified(self, response): + self.assertEquals(response.status_code, 304) + self.assertEquals(response.content, '') + + def testWithoutConditions(self): + response = self.client.get('/condition/') + self.assertFullResponse(response) + + def testIfModifiedSince(self): + self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = LAST_MODIFIED_STR + response = self.client.get('/condition/') + self.assertNotModified(response) + self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = EXPIRED_LAST_MODIFIED_STR + response = self.client.get('/condition/') + self.assertFullResponse(response) + + def testIfNoneMatch(self): + self.client.defaults['HTTP_IF_NONE_MATCH'] = ETAG + response = self.client.get('/condition/') + self.assertNotModified(response) + self.client.defaults['HTTP_IF_NONE_MATCH'] = EXPIRED_ETAG + response = self.client.get('/condition/') + self.assertFullResponse(response) + + # Several etags in If-None-Match is a bit exotic but why not? + self.client.defaults['HTTP_IF_NONE_MATCH'] = ', '.join([ETAG, EXPIRED_ETAG]) + response = self.client.get('/condition/') + self.assertNotModified(response) + + def testBothHeaders(self): + self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = LAST_MODIFIED_STR + self.client.defaults['HTTP_IF_NONE_MATCH'] = ETAG + response = self.client.get('/condition/') + self.assertNotModified(response) + self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = EXPIRED_LAST_MODIFIED_STR + self.client.defaults['HTTP_IF_NONE_MATCH'] = ETAG + response = self.client.get('/condition/') + self.assertFullResponse(response) + self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = LAST_MODIFIED_STR + self.client.defaults['HTTP_IF_NONE_MATCH'] = EXPIRED_ETAG + response = self.client.get('/condition/') + self.assertFullResponse(response) + + def testSingleConditions(self): + self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = LAST_MODIFIED_STR + response = self.client.get('/condition/last_modified/') + self.assertNotModified(response) + response = self.client.get('/condition/etag/') + self.assertFullResponse(response, check_last_modified=False) + + del self.client.defaults['HTTP_IF_MODIFIED_SINCE'] + self.client.defaults['HTTP_IF_NONE_MATCH'] = ETAG + response = self.client.get('/condition/etag/') + self.assertNotModified(response) + response = self.client.get('/condition/last_modified/') + self.assertFullResponse(response, check_etag=False) + + self.client.defaults['HTTP_IF_MODIFIED_SINCE'] = EXPIRED_LAST_MODIFIED_STR + self.client.defaults['HTTP_IF_NONE_MATCH'] = EXPIRED_ETAG + response = self.client.get('/condition/last_modified/') + self.assertFullResponse(response, check_etag=False) + response = self.client.get('/condition/etag/') + self.assertFullResponse(response, check_last_modified=False) \ No newline at end of file Index: tests/regressiontests/conditional_get/urls.py =================================================================== --- tests/regressiontests/conditional_get/urls.py (revision 0) +++ tests/regressiontests/conditional_get/urls.py (revision 0) @@ -0,0 +1,8 @@ +from django.conf.urls.defaults import * +import views + +urlpatterns = patterns('', + ('^$', views.index), + ('^last_modified/$', views.last_modified), + ('^etag/$', views.etag), +) Index: tests/urls.py =================================================================== --- tests/urls.py (revision 6551) +++ tests/urls.py (working copy) @@ -14,4 +14,7 @@ # django built-in views (r'^views/', include('regressiontests.views.urls')), + + # conditional get views + (r'condition/', include('regressiontests.conditional_get.urls')), )