web/lib/django/contrib/auth/decorators.py
changeset 0 0d40e90630ef
child 29 cc9b7e14412b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/contrib/auth/decorators.py	Wed Jan 20 00:34:04 2010 +0100
@@ -0,0 +1,81 @@
+try:
+    from functools import update_wrapper
+except ImportError:
+    from django.utils.functional import update_wrapper  # Python 2.3, 2.4 fallback.
+
+from django.contrib.auth import REDIRECT_FIELD_NAME
+from django.http import HttpResponseRedirect
+from django.utils.http import urlquote
+
+def user_passes_test(test_func, login_url=None, redirect_field_name=REDIRECT_FIELD_NAME):
+    """
+    Decorator for views that checks that the user passes the given test,
+    redirecting to the log-in page if necessary. The test should be a callable
+    that takes the user object and returns True if the user passes.
+    """
+    def decorate(view_func):
+        return _CheckLogin(view_func, test_func, login_url, redirect_field_name)
+    return decorate
+
+def login_required(function=None, redirect_field_name=REDIRECT_FIELD_NAME):
+    """
+    Decorator for views that checks that the user is logged in, redirecting
+    to the log-in page if necessary.
+    """
+    actual_decorator = user_passes_test(
+        lambda u: u.is_authenticated(),
+        redirect_field_name=redirect_field_name
+    )
+    if function:
+        return actual_decorator(function)
+    return actual_decorator
+
+def permission_required(perm, login_url=None):
+    """
+    Decorator for views that checks whether a user has a particular permission
+    enabled, redirecting to the log-in page if necessary.
+    """
+    return user_passes_test(lambda u: u.has_perm(perm), login_url=login_url)
+
+class _CheckLogin(object):
+    """
+    Class that checks that the user passes the given test, redirecting to
+    the log-in page if necessary. If the test is passed, the view function
+    is invoked. The test should be a callable that takes the user object
+    and returns True if the user passes.
+
+    We use a class here so that we can define __get__. This way, when a
+    _CheckLogin object is used as a method decorator, the view function
+    is properly bound to its instance.
+    """
+    def __init__(self, view_func, test_func, login_url=None, redirect_field_name=REDIRECT_FIELD_NAME):
+        if not login_url:
+            from django.conf import settings
+            login_url = settings.LOGIN_URL
+        self.view_func = view_func
+        self.test_func = test_func
+        self.login_url = login_url
+        self.redirect_field_name = redirect_field_name
+        
+        # We can't blindly apply update_wrapper because it udpates __dict__ and 
+        # if the view function is already a _CheckLogin object then 
+        # self.test_func and friends will get stomped. However, we also can't 
+        # *not* update the wrapper's dict because then view function attributes
+        # don't get updated into the wrapper. So we need to split the
+        # difference: don't let update_wrapper update __dict__, but then update
+        # the (parts of) __dict__ that we care about ourselves.
+        update_wrapper(self, view_func, updated=())
+        for k in view_func.__dict__:
+            if k not in self.__dict__:
+                self.__dict__[k] = view_func.__dict__[k]
+
+    def __get__(self, obj, cls=None):
+        view_func = self.view_func.__get__(obj, cls)
+        return _CheckLogin(view_func, self.test_func, self.login_url, self.redirect_field_name)
+    
+    def __call__(self, request, *args, **kwargs):
+        if self.test_func(request.user):
+            return self.view_func(request, *args, **kwargs)
+        path = urlquote(request.get_full_path())
+        tup = self.login_url, self.redirect_field_name, path
+        return HttpResponseRedirect('%s?%s=%s' % tup)