What are good ways to design or diagram state?

Question

The issue that prompted me to ask this is a web form that was not persisting data the way I expected it to. That's vague, but the point is, what do you like to do to model state, flow of data, and so forth?

Answer 1

I'll second the whiteboard answer and add that explaining what is supposed to be happening, following by verbalizing what the the code is actually doing, along with a basic graphic is hugely helpful for any project.

Answer 2

Whiteboard as well, but be familiar with the UML diagrams. I've had a lot of luck with sequence diagrams--they do a good job of describing the interactions between parts of a system.

I've seen people use state diagrams, but they don't contain as much detailed information--sequence diagrams impressed the hell out of me when I first saw them.

Answer 3

The UML has 2 diagrams that may be useful

State diagrams for modelling state.

Activity diagrams for modelling data flow.

Answer 4

I'll put my obvious (to me) answer, which is to use the whiteboard. Love the whiteboard.

Answer 5

Graphviz is a great tool for diagramming state machines (once you've worked them out on the whiteboard).

Answer 6

I think the typical models work fine:

for example - state diagrams

http://en.wikipedia.org/wiki/State_diagram

I second the whiteboard use. They are second to none in working on state, flow, etc.