Nested arrows or pipes

0 votes
asked Jun 15, 2021 in Question / help by Andreas
Hello,

is it possible to "nest arrows"? E.g. looking like pipes. Ideally in a component diagram.

My use case: Model an API call from component A to component B (My picture in my mind is now an arrow from A to B).

The API call is secured on application level with WSS (My picture in my mind is now: the arrow is now in a "pipe" labeled with WSS)

The API call is additionally secured on transport level with TLS (My picture in my mind is now: the pipe is now wrapped with another "pipe" labeled with TLS)

If you have any other ideas on how to draw this, I am glad for any idea.

Andreas

2 Answers

0 votes
answered Jun 16, 2021 by Martin (6,780 points)

No, I couldn't find a way to overlay arrows.  

The only idea I can think of is to put text above and below the arrow, the text can be made to look like a pipe by using underline or strikeout, or custom sprites.  But it's rather fiddly (it is hard to get the top and bottom equal lengths/offsets, and sometimes the red arrow disappears (eg if you put G below E)).  But maybe you'll get some ideas.
(Click diagram for Source)

0 votes
answered Jun 16, 2021 by The-Lu (37,840 points)

Hello A. and M.,

Here is another workaround, using queue component, (but not nested arrow...):

@startuml
queue TLS {
  queue WSS {
    queue API
  }
}
[a] -> API
API -> [b]
@enduml

If that can help,
Regards,
Th.

commented Jun 16, 2021 by Andreas
Thanky you both, Martin and The-Lu!!

(I cannot vote as I am not registered)
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