From: Zooko O'Whielacronx <zooko@zooko.com>
Date: Wed, 23 May 2007 22:11:23 +0000 (-0700)
Subject: add in-line doc that Josh wrote as he was trying to understand this code
X-Git-Tag: allmydata-tahoe-0.3.0~61
X-Git-Url: https://git.rkrishnan.org/components/com_hotproperty/flags/index.php?a=commitdiff_plain;h=80b09b6d5438128c08a7799dd1cac43cd183bf45;p=tahoe-lafs%2Ftahoe-lafs.git

add in-line doc that Josh wrote as he was trying to understand this code
---

diff --git a/src/allmydata/util/observer.py b/src/allmydata/util/observer.py
index 97cfa3f5..01120816 100644
--- a/src/allmydata/util/observer.py
+++ b/src/allmydata/util/observer.py
@@ -3,6 +3,12 @@
 from twisted.internet import defer
 from foolscap.eventual import eventually
 
+"""The idiom we use is for the observed object to offer a method named
+'when_something', which returns a deferred.  That deferred will be fired when
+something happens.  The way this is typically implemented is that the observed
+has an ObserverList whose when_fired method is called in the observed's
+'when_something'."""
+
 class OneShotObserverList:
     """A one-shot event distributor."""
     def __init__(self):