How should I depict “User wants to see his profile” in a Dataflow Diagram? Maybe I shouldn't?

Question

I have a User that wants to see his online profile, in a site where he previously has registered at. I am in charge of making a Dataflow Diagram out of this situation. I know for sure that the System will return a Profile. That is why I put an arrow from System to User.

How can I express that the User is requesting his profile to the System? I can't think of a way of expressing that in a DFD. I guess it's maybe because you are only supposed to show data flow in a DFD and not actions/requests? Should I completly erase the arrow that goes from User to System(?See his profile?) ?

Context Diagram (Level 0 Dataflow Diagram)

Level 1 Dataflow Diagram

Thanks

Answer 1

No hard and fast answer to this. It's possible to argue against including it (could be considered a control flow, not a dataflow). However, assuming purpose of DFD is for human understanding (i.e. it's a picture to look at) go with what makes most sense to your audience.

If I were drawing it, I'd include the input flow on both L0 & L1 (probably named View Profile rather than Check his profile - I prefer imperative statements). It's both the event that triggers action, and will also likely carry data to identify the user.

I wouldn't however include the flow marked ??? on the L1 diagram. Reason: you're pulling data from a datastore so the query is implicit.

hth.