Can I combine two graphs together? Like a sequence and a state diagram?

Question

What I'm working on is basically a sequence diagram.  One entity sends another entity messages, in a flow of time.

But sometimes a message changes the state of an entity.  After that point, the entity responds differently to the same messages, and understands some different messages.

If was thinking of somehow placing a state diagram where the entity is in the sequence diagram, and showing the change of state.   Is that possible?

Think of a web page being tested in a player piano fashion.   You click the submit button, the form is accepted, and then a different page is displayed.   If you click the submit button again, something entirely different happens.

Comments

Please give an example (in plantumlcode) of such a mix.

Did you have a look at allow_mixing? (see also https://forum.plantuml.net/8086/allow-mixing?show=8086#q8086 and search the internet for e.g. plantuml mixed diagrams).

Answer 1

Hello R.,

You can use embedded diagram or sub-diagram with use of '{{' and '}}' on note (See similar question on /6947/embed-sub-diagrams-in-diagram-like-a-note):

Here is a proposal, with a simple "User State" embedded on a sequence diagram (with adding processing procedure just to avoid to repeat the state ):

@startuml
actor       Client       as C
participant Server       as S
control     "User state" as U

!procedure $UserState()
  title User state
  D : disconnected
  C : connected
  D -> C : connects
  C -> D : disconnects
!end procedure

== Init ==
note right U
  {{
  $UserState()
  state D #palegreen
  }}
end note

== Exchange ==
C -x S : Attempt to connect
note right U
  {{
  $UserState()
  state D #palegreen
  }}
end note
|||
C -> S : Connects
note right U
  {{
  $UserState()
  state C #palegreen
  }}
end note
S -> C : Ack
|||
@enduml

And the result:

[See on PlantUML online server]

If that can help,
Regards,
Th.