Comments on: Refactoring Day 18 : Replace exception with conditional http://lostechies.com/seanchambers/2009/08/18/refactoring-day-18-replace-exception-with-conditional/ Just another LosTechies site Thu, 13 Sep 2012 07:11:00 +0000 hourly 1 http://wordpress.org/?v=3.4.2 By: Quick Joe Smith http://lostechies.com/seanchambers/2009/08/18/refactoring-day-18-replace-exception-with-conditional/#comment-415 Quick Joe Smith Thu, 20 Aug 2009 12:35:52 +0000 /blogs/sean_chambers/archive/2009/08/18/refactoring-day-18-replace-exception-with-conditional.aspx#comment-415 Going with the example, it may depend on why the microwave can't start. It may be in use, it may be broken, it may not be plugged in. Returning false isn't going to shed much light on the problem. Sometimes just knowing something failed isn't enough. Both examples however do just that (return false). Perhaps it is better to combine conditional checking (eg, IsInUse, IsPluggedIn, IsBroken, etc.) with throwing the appropriate exception, enabling calling code to take proper action, such as microwave.PlugIn() or while(microwave.InUse) { Thread.sleep(1000); }. Going with the example, it may depend on why the microwave can’t start. It may be in use, it may be broken, it may not be plugged in. Returning false isn’t going to shed much light on the problem. Sometimes just knowing something failed isn’t enough.

Both examples however do just that (return false). Perhaps it is better to combine conditional checking (eg, IsInUse, IsPluggedIn, IsBroken, etc.) with throwing the appropriate exception, enabling calling code to take proper action, such as microwave.PlugIn() or while(microwave.InUse) { Thread.sleep(1000); }.

]]> By: Eyston http://lostechies.com/seanchambers/2009/08/18/refactoring-day-18-replace-exception-with-conditional/#comment-414 Eyston Tue, 18 Aug 2009 17:24:31 +0000 /blogs/sean_chambers/archive/2009/08/18/refactoring-day-18-replace-exception-with-conditional.aspx#comment-414 Maybe it is just a bad example ... but having to check a boolean result seems very c'ish doesn't it? If I call microwave.Start(food) and the microwave can't do it... is an exception appropriate? It seems like a message back to the caller on why it can't start would be useful ... but I don't know if an exception is an abuse or not (ie it doesn't seem that exceptional). Maybe it is just a bad example … but having to check a boolean result seems very c’ish doesn’t it?

If I call microwave.Start(food) and the microwave can’t do it… is an exception appropriate? It seems like a message back to the caller on why it can’t start would be useful … but I don’t know if an exception is an abuse or not (ie it doesn’t seem that exceptional).

]]> By: Rob White http://lostechies.com/seanchambers/2009/08/18/refactoring-day-18-replace-exception-with-conditional/#comment-413 Rob White Tue, 18 Aug 2009 15:34:51 +0000 /blogs/sean_chambers/archive/2009/08/18/refactoring-day-18-replace-exception-with-conditional.aspx#comment-413 I think the general idea is sound, but it's worth noting that this kind of code is vulnerable to race conditions, so the exception may still need to be thrown by Motor.Cook(food) I think the general idea is sound, but it’s worth noting that this kind of code is vulnerable to race conditions, so the exception may still need to be thrown by Motor.Cook(food)

]]>