1
在扭曲的应用程序中，我有一系列通过Observable模式进行交互的资源控制器/管理器类。一般来说，大多数观察者都会订阅特定的频道（例如“foo.bar.entity2”），但在某些情况下，我想知道特定频道中的所有事件（例如“foo。*”）我写了类似以下内容：支持多通道订户的Python可观察实现
from collections import defaultdict
class SimplePubSub(object):
def __init__(self):
self.subjects = defaultdict(list)
def subscribe(self, subject, callbackstr):
"""
for brevity, callbackstr would be a valid Python function or bound method but here is just a string
"""
self.subjects[subject].append(callbackstr)
def fire(self, subject):
"""
Again for brevity, fire would have *args, **kwargs or some other additional message arguments but not here
"""
if subject in self.subjects:
print "Firing callback %s" % subject
for callback in self.subjects[subject]:
print "callback %s" % callback
pubSub = SimplePubSub()
pubSub.subscribe('foo.bar', "foo.bar1")
pubSub.subscribe('foo.foo', "foo.foo1")
pubSub.subscribe('foo.ich.tier1', "foo.ich.tier3_1")
pubSub.subscribe('foo.ich.tier2', "foo.ich.tier2_1")
pubSub.subscribe('foo.ich.tier3', "foo.ich.tier2_1")
#Find everything that starts with foo
#say foo.bar is fired
firedSubject = "foo.bar"
pubSub.fire(firedSubject)
#outputs
#>>Firing callback foo.bar
#>>callback foo.bar1
#but let's say I want to add a callback for everything undr foo.ich
class GlobalPubSub(SimplePubSub):
def __init__(self):
self.globals = defaultdict(list)
super(GlobalPubSub, self).__init__()
def subscribe(self, subject, callback):
if subject.find("*") > -1:
#assumes global suscriptions would be like subject.foo.* and we want to catch all subject.foo's
self.globals[subject[:-2]].append(callback)
else:
super(GlobalPubSub, self).subscribe(subject, callback)
def fire(self, subject):
super(GlobalPubSub, self).fire(subject)
if self.globals:
for key in self.globals.iterkeys():
if subject.startswith(key):
for callback in self.globals[key]:
print "global callback says", callback
print "Now with global subscriptions"
print
pubSub = GlobalPubSub()
pubSub.subscribe('foo.bar', "foo.bar1")
pubSub.subscribe('foo.foo', "foo.foo1")
pubSub.subscribe('foo.ich.tier1', "foo.ich.tier3_1")
pubSub.subscribe('foo.ich.tier2', "foo.ich.tier2_1")
pubSub.subscribe('foo.ich.tier3', "foo.ich.tier2_1")
pubSub.subscribe("foo.ich.*", "All the ichs, all the time!")
#Find everything that starts with foo.ich
firedSubject = "foo.ich.tier2"
pubSub.fire(firedSubject)
#outputs
#>>Firing callback foo.bar
#>>callback foo.bar1
#>>Now with global subscriptions
#
#>>Firing callback foo.ich.tier2
#>>callback foo.ich.tier2_1
#>>global callback says All the ichs, all the time!
这样就好，没有诉诸某种奇特的构造（例如尝试）？我正在寻求一种肯定，即我正处于正确的轨道上，或者是一个纯粹的Python（没有外部库或服务）的全球订阅处理程序的更好的替代建议。