django1/django/utils/decorators.py

58 lines
2.3 KiB
Python

"Functions that help with dynamically creating decorators for views."
import types
def decorator_from_middleware(middleware_class):
"""
Given a middleware class (not an instance), returns a view decorator. This
lets you use middleware functionality on a per-view basis.
"""
def _decorator_from_middleware(*args, **kwargs):
# For historical reasons, these "decorators" are also called as
# dec(func, *args) instead of dec(*args)(func). We handle both forms
# for backwards compatibility.
has_func = True
try:
view_func = kwargs.pop('view_func')
except KeyError:
if len(args):
view_func, args = args[0], args[1:]
else:
has_func = False
if not (has_func and isinstance(view_func, types.FunctionType)):
# We are being called as a decorator.
if has_func:
args = (view_func,) + args
middleware = middleware_class(*args, **kwargs)
def decorator_func(fn):
return _decorator_from_middleware(fn, *args, **kwargs)
return decorator_func
middleware = middleware_class(*args, **kwargs)
def _wrapped_view(request, *args, **kwargs):
if hasattr(middleware, 'process_request'):
result = middleware.process_request(request)
if result is not None:
return result
if hasattr(middleware, 'process_view'):
result = middleware.process_view(request, view_func, *args, **kwargs)
if result is not None:
return result
try:
response = view_func(request, *args, **kwargs)
except Exception, e:
if hasattr(middleware, 'process_exception'):
result = middleware.process_exception(request, e)
if result is not None:
return result
raise
if hasattr(middleware, 'process_response'):
result = middleware.process_response(request, response)
if result is not None:
return result
return response
return _wrapped_view
return _decorator_from_middleware