Sequence Diagram (Aysu Keskin) - bounswe/bounswe2026group4 GitHub Wiki

Scope

This diagram models the happy path and primary alternative flows of the Register / Create Account use case, including its mandatory inclusion of Verify Email. It covers the interaction from the moment a guest submits the registration form until their email address is successfully confirmed and the account becomes active.

Assumptions

• A UserProfile is always created atomically with the User record, consistent with the User *── "1" UserProfile composition in the class diagram. Failure to create the profile is treated as a single transaction rollback, not a separate error branch.
• Input validation (empty fields, password strength, username format) is assumed to happen on the client side before fillForm() is sent and is therefore not shown.
• The db:UserDB lifeline represents the persistence layer as an abstraction; it is not a separate class in the domain model but a stand-in for whatever storage mechanism is used behind the User class.

Intentionally Left Out

• Infrastructure errors such as database timeouts or email delivery failures are not modelled. These are cross-cutting concerns better addressed at the architecture level rather than within a single use-case diagram.
• Resend verification code flow is a separate use case and is not included here.
• Admin-side visibility of newly created accounts is out of scope for this diagram.
• The internal implementation of hash() and generateCode() are shown as self-calls on u:User for completeness but their cryptographic details are intentionally abstracted away.