# "Extended" property class that implements Delphi property logic.
# Its constructor accepts attribute names as well as functions
# for a getter or/and setter parameters thus allowing "direct"
# access to underlying "real" attribute without additional coding.
class xproperty(property):
def __init__(self, fget=None, fset=None, fdel=None, doc=None):
property.__init__(
self,
(isinstance(fget, str) and (lambda obj: getattr(obj, fget))
or fget),
(isinstance(fset, str) and (lambda obj, val: setattr(obj, fset, val))
or fset),
fdel,
doc)
# A simple example of xproperty usage.
# The attribute 's' is converted to lowercase when assigned, but reading
# immediately returns the value of the "real" underlying attribute '_s'
# So, setting s ends up calling __sets; getting s simply returns _s
class Lower(object):
def __init__(self):
self._s = ''
def __sets(self, val):
if isinstance(val, str):
self._s = val.lower()
else:
self._s = val
s = xproperty('_s', __sets)
