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by Martin Fowler.
Original Post: Bliki: UmlAsNotes
Feed Title: Martin Fowler's Bliki
Feed URL: http://martinfowler.com/feed.atom
Feed Description: A cross between a blog and wiki of my partly-formed ideas on software development
Yesterday I was poking around a code base, looking at the domain
model part of the code. When exploring a code base, I like to take
notes to help me remember what I'm learning. For some code bases, in
particular domain models, I find it handy to sketch UML class diagrams.
UML has got rather out of fashion it seems. Although this isn't
good for me financially, I can't say I'm displeased to see a lot of
rather dodgy UMLisms going away. I continue to find it a useful
tool, as I did that morning. As I worked my way around the code I
would jot down classes and relationships, to see how the various
classes played together.
I don't use "reverse-engineering" tools for this. Such tools run
on your code base and automatically generate the class
diagram. Although this is quite straight-forward to do technically,
the result is rather useless. For me the value of a good diagram is
that it highlights the important stuff, and ignores what's not. So I
don't draw every class, let alone every relationship and feature. I
decide to jot down things that I think are important to remember,
particularly focusing on connections that often don't show up so
much when you're looking at the code. I also only use a little of
the endless class diagram syntax, and I'm not afraid of being sloppy
with it. [1]
When I'm doing this speed is important. Currently my favorite
tool for this kind of jotting is Umlet[2]. What I
like about it is that most of what you capture goes in as text,
using a wiki-ish markup. As a result I can quickly slap things in
there, using the mouse just to broadly move things around as
needed. It's a java program, so it suffers ugliness for
availability.
When I'm doing this, I do the diagrams just for me; so I don't
put effort into making them nice and clear for others. If I were to
produce diagrams to help explain the code to others, I'd approach
them differently. With notes I'm creating reminders for myself, with
explanatory diagrams I'm trying to communicate different things to
another audience. [3]
1: Actually I'm not very sloppy, because I
know the syntax so well that I'm unconsciously pretty accurate. But
the point is that people who are less familiar with the syntax
shouldn't worry about it in this mode of working.
2: Yes that home page is littered with
ads that make it hard to find the useful stuff.
3: I'd also use a different tool. If I'm going
to publish a diagram, I use OmniGraffle. I've loved its diffuse
shadows ever since DHH introduced it to
me.
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