# -*- coding: utf-8 -*-
"""Parts of this module is Copyright by Werkzeug Team."""
from __future__ import absolute_import
class Proxy(object):
"""Proxy to another object."""
# Code stolen from werkzeug.local.Proxy.
__slots__ = ('__local', '__args', '__kwargs', '__dict__', '__name__')
def __init__(self, local, args=None, kwargs=None, name=None):
object.__setattr__(self, '_Proxy__local', local)
object.__setattr__(self, '_Proxy__args', args or ())
object.__setattr__(self, '_Proxy__kwargs', kwargs or {})
if name is not None:
object.__setattr__(self, '__custom_name__', name)
@property
def __name__(self):
try:
return self.__custom_name__
except AttributeError:
return self._get_current_object().__name__
@property
def __module__(self):
return self._get_current_object().__module__
@property
def __doc__(self):
return self._get_current_object().__doc__
def _get_class(self):
return self._get_current_object().__class__
@property
def __class__(self):
return self._get_class()
def _get_current_object(self):
"""Return the current object. This is useful if you want the real
object behind the proxy at a time for performance reasons or because
you want to pass the object into a different context.
"""
if not hasattr(self.__local, '__release_local__'):
return self.__local(*self.__args, **self.__kwargs)
try:
return getattr(self.__local, self.__name__)
except AttributeError:
raise RuntimeError('no object bound to {0.__name__}'.format(self))
@property
def __dict__(self):
try:
return self._get_current_object().__dict__
except RuntimeError: # pragma: no cover
raise AttributeError('__dict__')
def __repr__(self):
try:
obj = self._get_current_object()
except RuntimeError: # pragma: no cover
return '<{0} unbound>'.format(self.__class__.__name__)
return repr(obj)
def __nonzero__(self):
try:
return bool(self._get_current_object())
except RuntimeError: # pragma: no cover
return False
def __unicode__(self):
try:
return unicode(self._get_current_object())
except RuntimeError: # pragma: no cover
return repr(self)
def __dir__(self):
try:
return dir(self._get_current_object())
except RuntimeError: # pragma: no cover
return []
def __getattr__(self, name):
if name == '__members__':
return dir(self._get_current_object())
return getattr(self._get_current_object(), name)
def __setitem__(self, key, value):
self._get_current_object()[key] = value
def __delitem__(self, key):
del self._get_current_object()[key]
def __setslice__(self, i, j, seq):
self._get_current_object()[i:j] = seq
def __delslice__(self, i, j):
del self._get_current_object()[i:j]
__setattr__ = lambda x, n, v: setattr(x._get_current_object(), n, v)
__delattr__ = lambda x, n: delattr(x._get_current_object(), n)
__str__ = lambda x: str(x._get_current_object())
__lt__ = lambda x, o: x._get_current_object() < o
__le__ = lambda x, o: x._get_current_object() <= o
__eq__ = lambda x, o: x._get_current_object() == o
__ne__ = lambda x, o: x._get_current_object() != o
__gt__ = lambda x, o: x._get_current_object() > o
__ge__ = lambda x, o: x._get_current_object() >= o
__cmp__ = lambda x, o: cmp(x._get_current_object(), o)
__hash__ = lambda x: hash(x._get_current_object())
__call__ = lambda x, *a, **kw: x._get_current_object()(*a, **kw)
__len__ = lambda x: len(x._get_current_object())
__getitem__ = lambda x, i: x._get_current_object()[i]
__iter__ = lambda x: iter(x._get_current_object())
__contains__ = lambda x, i: i in x._get_current_object()
__getslice__ = lambda x, i, j: x._get_current_object()[i:j]
__add__ = lambda x, o: x._get_current_object() + o
__sub__ = lambda x, o: x._get_current_object() - o
__mul__ = lambda x, o: x._get_current_object() * o
__floordiv__ = lambda x, o: x._get_current_object() // o
__mod__ = lambda x, o: x._get_current_object() % o
__divmod__ = lambda x, o: x._get_current_object().__divmod__(o)
__pow__ = lambda x, o: x._get_current_object() ** o
__lshift__ = lambda x, o: x._get_current_object() << o
__rshift__ = lambda x, o: x._get_current_object() >> o
__and__ = lambda x, o: x._get_current_object() & o
__xor__ = lambda x, o: x._get_current_object() ^ o
__or__ = lambda x, o: x._get_current_object() | o
__div__ = lambda x, o: x._get_current_object().__div__(o)
__truediv__ = lambda x, o: x._get_current_object().__truediv__(o)
__neg__ = lambda x: -(x._get_current_object())
__pos__ = lambda x: +(x._get_current_object())
__abs__ = lambda x: abs(x._get_current_object())
__invert__ = lambda x: ~(x._get_current_object())
__complex__ = lambda x: complex(x._get_current_object())
__int__ = lambda x: int(x._get_current_object())
__long__ = lambda x: long(x._get_current_object())
__float__ = lambda x: float(x._get_current_object())
__oct__ = lambda x: oct(x._get_current_object())
__hex__ = lambda x: hex(x._get_current_object())
__index__ = lambda x: x._get_current_object().__index__()
__coerce__ = lambda x, o: x.__coerce__(x, o)
__enter__ = lambda x: x._get_current_object().__enter__()
__exit__ = lambda x, *a, **kw: x._get_current_object().__exit__(*a, **kw)
__reduce__ = lambda x: x._get_current_object().__reduce__()
[docs]class PromiseProxy(Proxy):
"""This is a proxy to an object that has not yet been evaluated.
:class:`Proxy` will evaluate the object each time, while the
promise will only evaluate it once.
"""
def _get_current_object(self):
try:
return object.__getattribute__(self, '__thing')
except AttributeError:
return self.__evaluate__()
def __evaluated__(self):
try:
object.__getattribute__(self, '__thing')
except AttributeError:
return False
return True
def __maybe_evaluate__(self):
return self._get_current_object()
def __evaluate__(self):
try:
thing = Proxy._get_current_object(self)
object.__setattr__(self, '__thing', thing)
return thing
finally:
object.__delattr__(self, '_Proxy__local')
object.__delattr__(self, '_Proxy__args')
object.__delattr__(self, '_Proxy__kwargs')
[docs]def maybe_evaluate(obj):
try:
return obj.__maybe_evaluate__()
except AttributeError:
return obj