2008-11-05 08:48:00
Posted by kdawson on Tuesday November 04, @08:02PM
from the good-or-great dept.
Programming
eldavojohn writes "I began coding for a project that had simple requirements
for my employer Web services and a test application for them. But
requirements have been creeping, as they always do. Initially I had decided to
use the Spring Framework with Hibernate. And I re-used a lot of libraries that
made things simple and quick for me. The new requests coming in involve
capabilities beyond those of the frameworks. Now, I used to be told that good
programmers write code and great programmers reuse code. It's starting to look
like I would have saved myself a whole lot of time if I had written the
database transaction using JDBC instead of Hibernate now that I'm married to
this object model framework, some of this stuff doesn't look doable. So what is
better for the majority of software projects out there: reuse code, or code
from scratch? What elements or characteristics of a problem point to one option
over the other?"
It's not rewriting code or reusing code that makes you a great programmer. It's
knowing when to rewrite code and when to reuse code that makes you a great
programmer.
- the first case is trying to make the best of what you have and building on
that
To add to this, never ever simply "reuse" code; if you just copy and paste
you'll end up with a horribly designed hack job worth of TDWTF. Instead, take
what you have and massage it into place.
In this particular case, it sounds like your design no longer hashes well with
the requirements. My suggestion is to start rewriting/reworking isolated
portions of the code base and create a temporary compatibility layer (if
necessary) to interface with the old code. Continue doing this until the entire
application is converted over to the new design.
Did he really make a mistake? He already has one version out and is now finding
out what the software really needs to do. That sounds pretty damn successful to
me. Now he's dithering about rewriting and replacing some of the libraries,
which he would have had to do anyway even if they were custom-written.
If he had written everything from scratch:
existing libraries that he used?
needs were actually quite typical, and well-served by existing libraries?
His original choice was correct. As far as replacing Hibernate, he's in just as
good a position now as he would have been if he had written his own persistence
layer. Remember, he chose Hibernate, which turned out to be unsuitable, because
didn't know the requirements when he started. He would have been damn lucky if
he had just happened to develop a custom persistance layer that neatly
anticipated the unknown requirements. So, ripping out or rewriting the
persistence layer was inevitable. If you're going to throw code away, it might
as well be code that you got for free, instead of code that you sweated and
toiled over.
If you're really dead set against replacing or rewriting any libraries, the
only way to improve your odds is to use the biggest, oldest, kitchen-sinkiest,
most bloatiest library you can find.
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On the spot!! If the "poster" hadn't reused code from the get-go he was
probably still coding. But instead of now making a choice between "hanging in"
and "starting to rewrite", there is a third and IMHO better option: Throw out
the framework that doesn't fit anymore and replace it with a better fitting
one. Don't jump immediately into the "and now I've to write it all from
scratch" excuse.
Your original "reuse" decision was the right one, but appearently you didn't
pick the right framework. Which is normal, because at the beginning of the
project you didn't know exactly what the requirements would be. Based on your
improved knowledge of the application, you should redo your investigation of
frameworks and find one that has the right fit.
And if you can't seem to find one that fits, you need to do some deep-deep-deep
thinking. Is your situation really so unique that nothing "standard" out there
will fit in, or is it the too often happening "not invented here" syndrome.
Don't fall into the trap of "I can do it better myself". Yes, I'm sure you can
:-), but you won't have the time!! Or better said, your boss won't allow you
the time.
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If you'd tried to write it all yourself from scratch from the beginning you'd
still be coding and you wouldn't have gotten the feedback about what needs to
change as quickly. Prototype quickly then optimize later.