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