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umldirectionsequence-diagramplantuml

PlantUML create in a different direction

is there a way to control where in a plantUML sequence diagram an object is created? Have a look at this simple example. Here I would like to have the GUI between the Console and the user.

enter image description here

The Code for this diagram looks like this: 

 /*
 * 
 * @startuml
 * skinparam sequenceParticipant underline
 * 
 * actor User
 * participant "Console" 
 * database "DB"
 * activate User
 * 
 * User -> Console : giveMeGUI()
 * activate Console
 * create GUI
 * Console -> GUI
 * GUI -> User : Hi there 
 * @enduml
 */

Thank you for your help

Solution

  • While it is not in the UML specifications, the convention for ordering lifelines is generally depicted in the order in which they are first used and/or created. Having GUI appear before Console would at a moment's glance indicate that it is created/used before Console, though closer inspection would show that it is created by Console.

    Is it maybe that you don't like the GUI response crossing over Console's execution specification. If so, unless giveMeGUI()'s execution persist beyond GUI creation, it should be deactivated anyways.

    For example

    @startuml
skinparam sequenceParticipant underline

actor User
participant "Console" 
activate User

User -> Console : giveMeGUI()
activate Console
create GUI
Console -> GUI : <<create>>
deactivate Console
activate GUI
GUI -> User : Hi there 
deactivate GUI
database "DB"
@enduml

    would result in the following

    enter image description here