Ticket #730: middleware_dict_single_instances_basic_sanity_checks-validation.diff

django/conf/project_template/settings.py

@@ -57 +57 @@
-#     'django.template.loaders.eggs.load_template_source',
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-ROOT_URLCONF = '{{ project_name }}.urls'
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django/conf/global_settings.py

@@ -291 +291 @@
-# MIDDLEWARE #
-##############
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-############
-# SESSIONS #

django/core/handlers/base.py

@@ -1 +1 @@
-import sys
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-from django import http
+from django.core import exceptions
-from django.core import signals
-from django.utils.encoding import force_unicode
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@@ -16 +17 @@
-    def __init__(self):
-        self._request_middleware = self._view_middleware = self._response_middleware = self._exception_middleware = None
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-        self._request_middleware = []
-        self._view_middleware = []
-        self._response_middleware = []
-        self._exception_middleware = []
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-            if hasattr(mw_instance, 'process_request'):
-                self._request_middleware.append(mw_instance.process_request)
-            if hasattr(mw_instance, 'process_view'):
@@ -57 +34 @@
-            if hasattr(mw_instance, 'process_exception'):
-                self._exception_middleware.insert(0, mw_instance.process_exception)
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+    def _load_middleware_from_dict(self, mw_dict):
+        # fill the instances dict so that we have only one instance of each
+        # middleware
+        mw_instances = _middleware_instances_from_dict(mw_dict)
+        # it would be easy to do validation here, but it would be expensive
+        # for mw_path, mw_inst in mw_instances.items():
+        #   for attr in ('request', 'view', 'response', 'exception'):
+        #       if hasattr(mw_inst, attr) and mw_path not in mw_dict[attr]:
+        #           raise ImproperlyConfigured("")
+
+        self._request_middleware = _particular_middleware_from_dicts('request',
+                mw_instances, mw_dict)
+        self._view_middleware = _particular_middleware_from_dicts('view',
+                mw_instances, mw_dict)
+        self._response_middleware = _particular_middleware_from_dicts('response',
+                mw_instances, mw_dict)
+        self._exception_middleware = _particular_middleware_from_dicts('exception',
+                mw_instances, mw_dict)
+
+    def load_middleware(self):
+        """
+        Populate middleware lists from settings.MIDDLEWARE_CLASSES.
+
+        Must be called after the environment is fixed (see __call__).
+        """
+        from django.conf import settings
+        if isinstance(settings.MIDDLEWARE_CLASSES, (tuple, list)):
+            self._load_middleware_from_list(settings.MIDDLEWARE_CLASSES)
+        elif isinstance(settings.MIDDLEWARE_CLASSES, (dict)):
+            self._load_middleware_from_dict(settings.MIDDLEWARE_CLASSES)
+        else:
+            raise exceptions.ImproperlyConfigured("MIDDLEWARE_CLASSES setting "
+                    "has to be either a tuple, list or a dict.")
+
-    def get_response(self, request):
-        "Returns an HttpResponse object for the given HttpRequest"
-exceptions, 
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-        from django.conf import settings
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-        # Apply request middleware
@@ -171 +182 @@
-            response = func(request, response)
-        return response
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+def validate_middleware(self):
+    # A very rough attempt at validation, doesn't load the middleware.
+    # Note that this assumes that if middleware has a process_foo method,
+    # then it has to be registered in MIDDLEWARE_CLASSES['foo'].
+    from django.conf import settings
+    # if MIDDLEWARE_CLASSES is a list, no easy way to validate
+    if isinstance(settings.MIDDLEWARE_CLASSES, (dict)):
+        mw_dict = settings.MIDDLEWARE_CLASSES
+        mw_instances = _middleware_instances_from_dict(mw_dict)
+        for mw_path, mw_inst in mw_instances.items():
+            for attr in ('request', 'view', 'response', 'exception'):
+                if hasattr(mw_inst, attr) and mw_path not in mw_dict[attr]:
+                    raise exceptions.ImproperlyConfigured("%s has to "
+                            "be enabled for %s processing in "
+                            "MIDDLEWARE_CLASSES setting." % (mw_path, attr))
+
-def get_script_name(environ):
-    """
-    Returns the equivalent of the HTTP request's SCRIPT_NAME environment
@@ -195 +222 @@
-        return force_unicode(script_url[:-len(environ.get('PATH_INFO', ''))])
-    return force_unicode(environ.get('SCRIPT_NAME', u''))
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+def _middleware_instance_from_path(middleware_path):
+    try:
+        dot = middleware_path.rindex('.')
+    except ValueError:
+        raise exceptions.ImproperlyConfigured, '%s isn\'t a middleware module' % middleware_path
+    mw_module, mw_classname = middleware_path[:dot], middleware_path[dot+1:]
+    try:
+        mod = __import__(mw_module, {}, {}, [''])
+    except ImportError, e:
+        raise exceptions.ImproperlyConfigured, 'Error importing middleware %s: "%s"' % (mw_module, e)
+    try:
+        mw_class = getattr(mod, mw_classname)
+    except AttributeError:
+        raise exceptions.ImproperlyConfigured, 'Middleware module "%s" does not define a "%s" class' % (mw_module, mw_classname)
+    # I'm ignoring the MiddlewareNotUsed exception as it's not used in Django
+    # according to grep, not documented and the only use case I can see is to
+    # raise it in custom middleware __init__ to disable the middleware
+    # temporarily. That can be better achieved with disabling it in settings
+    # (where it is explicit and visible). If everybody is happy with that, the
+    # exception should be removed from core.exceptions. See also #7820.
+    return mw_class()
+
+def _particular_middleware_from_dicts(mw_type, mw_instance_dict, mw_dict):
+    mw_instance_list = []
+    for mw_path in mw_dict.get(mw_type, []):
+        mw_instance = mw_instance_dict[mw_path]
+        if not hasattr(mw_instance, 'process_' + mw_type):
+            raise exceptions.ImproperlyConfigured("%s middleware needs "
+                    "a 'process_%s' method, but it's missing from %s."
+                    % (mw_type.title(), mw_type, mw_path))
+        mw_instance_list.append(mw_instance)
+    return mw_instance_list
+
+def _middleware_instances_from_dict(mw_dict):
+    mw_instances = {}
+    for mw_path_tuple in mw_dict.values():
+        for mw_path in mw_path_tuple:
+            if mw_path not in mw_instances:
+                mw_instances[mw_path] = _middleware_instance_from_path(mw_path)
+    return mw_instances