UML Diagrams with Graphviz

I worked on creating some plausible-looking diagrams for representing object inheritance (this is for my forthcoming book). Since I know I’ll forget how I did it, I wanted to share while I can remember!

digraph Couriers {
fontname = "Bitstream Vera Sans"
fontsize = 8

node [
fontname = "Bitstream Vera Sans"
fontsize = 8
shape = "record"

edge [
arrowtail = "empty"

Courier [
label = "{Courier|+ name : string\l+ home_country : string\l|+ calculateShipping() : float\l+ ship(): boolean\l}"

Monotype [
label = "{MonotypeDelivery|\l|+ ship(): boolean\l}"

Pigeon [
label = "{PigeonPost|\l|+ ship(): boolean\l}"

Courier -> Pigeon [dir=back]
Courier -> Monotype [dir=back]

And the resulting diagram:
UML diagram

Working out the arrow styles and that I then needed to style the tail rather than the head was a puzzle. Beyond that, the record shape with lines worked well enough for this example, and I was pleased with the result. I find graphviz gives a very “clean” output – not pretty, perhaps, but easier on the eye than anything I could draw myself!

5 thoughts on “UML Diagrams with Graphviz

  1. Hello,

    I’m very interested about creating class diagrams using graphviz, but I wonder how you can create complex class with it? I mean when you have lots of methods and variables, how do you escape the label property so it does not take 300 columns in your editor?

    • Honestly I would probably have the class details somewhere else like a config file, and then generate the dot source for the graphviz picture. It’s not particularly human-friendly.

    • I simply formatted it with newlines and it worked for me:
      MyIdea [

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