realms-wiki/realms/lib/hook.py
2014-11-10 10:54:46 -06:00

60 lines
1.4 KiB
Python

from flask.ext.sqlalchemy import DeclarativeMeta
from functools import wraps
def hook_func(name, fn):
@wraps(fn)
def wrapper(self, *args, **kwargs):
for hook, a, kw in self.__class__._pre_hooks.get(name) or []:
hook(*args, **kwargs)
rv = fn(self, *args, **kwargs)
# Attach return value for post hooks
kwargs.update(dict(rv=rv))
for hook, a, kw in self.__class__._post_hooks.get(name) or []:
hook(*args, **kwargs)
return rv
return wrapper
class HookMixinMeta(type):
def __new__(cls, name, bases, attrs):
super_new = super(HookMixinMeta, cls).__new__
for key, value in attrs.items():
if callable(value):
attrs[key] = hook_func(key, value)
return super_new(cls, name, bases, attrs)
class HookMixin(object):
__metaclass__ = HookMixinMeta
_pre_hooks = {}
_post_hooks = {}
@classmethod
def after(cls, method_name):
def outer(f, *args, **kwargs):
cls._post_hooks.setdefault(method_name, []).append((f, args, kwargs))
return f
return outer
@classmethod
def before(cls, method_name):
def outer(f, *args, **kwargs):
cls._pre_hooks.setdefault(method_name, []).append((f, args, kwargs))
return f
return outer
class HookModelMeta(DeclarativeMeta, HookMixinMeta):
pass