Why is this activity diagram correct?

[Jefferson111]

First issue I have, from what I have read and understood, authentication of the user is independent of wallet registration by user and balance checking. However, the diagram indicates that the authentication of the user must be checked first before checking wallet registration.

The second issue I have is the prompt for cash payment before the end? Shouldn't it be executed at the point where I marked my x? (Prompt for cash payment should only happen when there is an error condition)

This is taken from 1819S2 Part 2

[Jefferson111]

Ok, nevermind, identifying wallet service is not checking wallet registration.

[okkhoy]

prompt cash payment happens when any of the errors occur. There is nothing wrong in adding a prompt pay by cash at each X locations.

[aquohn]

Yes, but the issue is that it prompts for cash payment even along the success path.

[okkhoy]

Oh wait! You are right. My mistake; after pay for purchase, has to go to the end; not the one given.

[aquohn]

Doesn't it need to pass through all the join nodes too?

[Jefferson111]

With regards to this, I was thinking about this, which may allow it to not pass through the join nodes. As for directly pointing to the same end point, I am not sure.

Doesn't it need to pass through all the join nodes too?

[Jefferson111]

https://stackoverflow.com/questions/41870513/how-to-show-attribute-as-readonly-in-uml 🤔