John Du Hart <compwhizii <at> gmail.com> writes:
It's just another style I've encountered on
other projects and I
personally like.
The syntax itself is fine, but at Wikia we have found (after a recent post
mortem) that out of 23 "Fatal Error" code defects found in production,
7 of them were due to method calls on null object references. If any
method in that chain returns null then the request fails. It most cases
core MediaWiki objects do return a valid stub object of some kind, but
not all of them do (and in some cases they return null. intermittently
so the code works "most of the time", which is in many ways the worse
scenario). Introducing a pattern like this in a code base this large is
therefore problematic. The "clean looking code" benefit is perhaps
outweighed by the fact that you need to add extra "if" conditions or
try/catch blocks everywhere to handle local null object exceptions.
In our case, we are trying to ensure during code reviews that we just
check for null objects in all "if" conditions, which does also lead to more
highly nested and less readable code.
Everything is a tradeoff, but IMHO you do need to check for null in chains
like that, which means you can't really get away with it (at least not for
long).