Comments on 0xABADBABE - computer science iside and outside: Tell, don't ask. Law of Demeter

Rrrichi, thank you for the correction, I made a mi...

2011-01-05T08:45:44.329+02:00

Rrrichi, thank you for the correction, I made a mistake in example.
It's "not OK" example because we violate Demeter Law calling method on 'child' object and we pass pizza as a parameter:

Slice slice = pizza.getSlice();
slice.decorate();

Is there an error in example #6 or it is general &...

2010-12-28T04:01:30.297+02:00

Is there an error in example #6 or it is general "not OK" case that even will not allow to compile code? =)

Hey, No problem, I just want to break my stereotyp...

2010-12-13T19:52:07.785+02:00

Hey,
No problem, I just want to break my stereotypes again and move forward in TDD and all the stuff.
Definitely, facades eg. managers are really important party of any big application, especially frameworks.
I've often experienced functionality hell in outsourcing projects: tens or even hundred of services, without any entry point.

Hey, thanks for such a good summary and putting th...

2010-12-10T12:39:58.959+02:00

Hey, thanks for such a good summary and putting things together.

I have noticed another thing in large projects. Your domain-specific object base grows, if you build dependency tree according to OOD & OOP patterns applied to these objects, you end up with a huge number of separate objects with "random" dependencies. Of course, they are not that random, but architecture starts having many shapes and it becomes difficult to maintain.

So one of solutions is to introduce service layer holding algorithms and functionality wrapped up into "managers" like Session.XYZObjectManager, Session.KLMObjectManager...

1) Hard to troubleshoot NullPointerException 2) Ha...

2010-12-08T23:49:54.746+02:00

1) Hard to troubleshoot NullPointerException
2) Hard to write unit test for it.
3) Not easy to debug

Unless it's chaining programming style code, eg. each method invocation return instance of same object...

What's wrong with writing this? orderLine.get...

2010-12-08T19:40:54.934+02:00

What's wrong with writing this?

orderLine.getGroup().getOrder().getCustomer().getAddress().getPostalCode()