Create vertical window in sequence diagram

Question

I'm trying to reproduce following sequence diagram:

I can't reproduce the vertical arrow. Say I have participants A (left) and B (right)
A -> B++
B -> B ; Set Req
A <<-- B --
deactivate A

for the first part and (to workaround activate/deactivate error message):

B <-[hidden]-> B : After 2 years
activate B
B -> B : Set Req

However, I get the 2 rectangles right, but no visible vertical arrow due to the hidden. How can I achieve this?

Answer 1

Hello I.,

Here is a proposal with `teoz` and `vertical arrow`:

@startuml
!pragma teoz true
A -> B++
B -> B : Set Req
A <<-- B --
deactivate A

{start} B -[hidden]-> B
B -[hidden]-> B
{end} B -[hidden]-> B

{start} <-> {end} : After 2 years
activate B
B -> B : Set Req
@enduml

See also doc. here:

• https://plantuml.com/sequence-diagram

If that can help,

Regards,
Th.