diff options
Diffstat (limited to 'paste/util/classinit.py')
| -rw-r--r-- | paste/util/classinit.py | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/paste/util/classinit.py b/paste/util/classinit.py new file mode 100644 index 0000000..e4e6b28 --- /dev/null +++ b/paste/util/classinit.py @@ -0,0 +1,42 @@ +# (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org) +# Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php + +class ClassInitMeta(type): + + def __new__(meta, class_name, bases, new_attrs): + cls = type.__new__(meta, class_name, bases, new_attrs) + if (new_attrs.has_key('__classinit__') + and not isinstance(cls.__classinit__, staticmethod)): + setattr(cls, '__classinit__', + staticmethod(cls.__classinit__.im_func)) + if hasattr(cls, '__classinit__'): + cls.__classinit__(cls, new_attrs) + return cls + +def build_properties(cls, new_attrs): + """ + Given a class and a new set of attributes (as passed in by + __classinit__), create or modify properties based on functions + with special names ending in __get, __set, and __del. + """ + for name, value in new_attrs.items(): + if (name.endswith('__get') or name.endswith('__set') + or name.endswith('__del')): + base = name[:-5] + if hasattr(cls, base): + old_prop = getattr(cls, base) + if not isinstance(old_prop, property): + raise ValueError( + "Attribute %s is a %s, not a property; function %s is named like a property" + % (base, type(old_prop), name)) + attrs = {'fget': old_prop.fget, + 'fset': old_prop.fset, + 'fdel': old_prop.fdel, + 'doc': old_prop.__doc__} + else: + attrs = {} + attrs['f' + name[-3:]] = value + if name.endswith('__get') and value.__doc__: + attrs['doc'] = value.__doc__ + new_prop = property(**attrs) + setattr(cls, base, new_prop) |