ActiveSupport's memoize has a dangerous feature you might not know about.
Assume you have
class DeepThought
extend ActiveSupport::Memoizable
def life_universe_and_everything
# some lengthy calculation returning 42
end
memoize :life_universe_and_everything
end
Then #life_universe_and_everything will of course cache the result after calculating it once. However, you can trigger a recalculation by calling #life_universe_and_everything(true).
If, however, your method looks like
def life_universe(and_everything = false)
...
end
memoize :life_universe
a call to #life_universe(true) will actually trigger a reload and not pass the parameter at all.
To clarify: This not only disables the memoization, but will also return wrong results!
The best solution is to use the Memoizer gem instead.
Posted by Tobias Kraze to makandra dev (2011-11-07 15:10)