State Diagram
State diagrams are used to give an abstract description of the behavior of a system. This behavior is represented as a series of events that can occur in one or more possible states.
Simple State
You can use[*] for the starting point and ending point of the state diagram. Use --> for arrows.
@startuml
[*] --> State1
State1 --> [*]
State1 : this is a string
State1 : this is another string
State1 -> State2
State2 --> [*]
@enduml
Change state rendering
You can use hide empty description to render state as simple box.
@startuml
hide empty description
[*] --> State1
State1 --> [*]
State1 : this is a string
State1 : this is another string
State1 -> State2
State2 --> [*]
@enduml
Composite state
A state can also be composite. You have to define it using the state keywords and brackets.
@startuml
scale 350 width
[*] --> NotShooting
state NotShooting {
[*] --> Idle
Idle --> Configuring : EvConfig
Configuring --> Idle : EvConfig
}
state Configuring {
[*] --> NewValueSelection
NewValueSelection --> NewValuePreview : EvNewValue
NewValuePreview --> NewValueSelection : EvNewValueRejected
NewValuePreview --> NewValueSelection : EvNewValueSaved
state NewValuePreview {
State1 -> State2
}
}
@enduml
Long name
You can also use the state keyword to use long description for states.
@startuml
scale 600 width
[*] -> State1
State1 --> State2 : Succeeded
State1 --> [*] : Aborted
State2 --> State3 : Succeeded
State2 --> [*] : Aborted
state State3 {
state "Accumulate Enough Data\nLong State Name" as long1
long1 : Just a test
[*] --> long1
long1 --> long1 : New Data
long1 --> ProcessData : Enough Data
}
State3 --> State3 : Failed
State3 --> [*] : Succeeded / Save Result
State3 --> [*] : Aborted
@enduml
Fork
You can also fork and join using the <<fork>> and <<join>> stereotypes.
@startuml
state fork_state <<fork>>
[*] --> fork_state
fork_state --> State2
fork_state --> State3
state join_state <<join>>
State2 --> join_state
State3 --> join_state
join_state --> State4
State4 --> [*]
@enduml
Concurrent state
You can define concurrent state into a composite state using either -- or || symbol as separator.
@startuml
[*] --> Active
state Active {
[*] -> NumLockOff
NumLockOff --> NumLockOn : EvNumLockPressed
NumLockOn --> NumLockOff : EvNumLockPressed
--
[*] -> CapsLockOff
CapsLockOff --> CapsLockOn : EvCapsLockPressed
CapsLockOn --> CapsLockOff : EvCapsLockPressed
--
[*] -> ScrollLockOff
ScrollLockOff --> ScrollLockOn : EvCapsLockPressed
ScrollLockOn --> ScrollLockOff : EvCapsLockPressed
}
@enduml
Arrow direction
You can use -> for horizontal arrows. It is possible to force arrow's direction using the following syntax:
-down->(default arrow)-right->or->-left->-up->
@startuml
[*] -up-> First
First -right-> Second
Second --> Third
Third -left-> Last
@enduml
-d- instead of -down-) or the two first characters (-do-). Please note that you should not abuse this functionality : Graphviz gives usually good results without tweaking.
Note
You can also define notes using note left of, note right of, note top of, note bottom of keywords.
You can also define notes on several lines.
@startuml
[*] --> Active
Active --> Inactive
note left of Active : this is a short\nnote
note right of Inactive
A note can also
be defined on
several lines
end note
@enduml
You can also have floating notes.
@startuml
state foo
note "This is a floating note" as N1
@enduml
More in notes
You can put notes on composite states.
@startuml
[*] --> NotShooting
state "Not Shooting State" as NotShooting {
state "Idle mode" as Idle
state "Configuring mode" as Configuring
[*] --> Idle
Idle --> Configuring : EvConfig
Configuring --> Idle : EvConfig
}
note right of NotShooting : This is a note on a composite state
@enduml
Skinparam
You can use the skinparam command to change colors and fonts for the drawing.
You can use this command :
- In the diagram definition, like any other commands,
- In an included file,
- In a configuration file, provided in the command line or the ANT task.
@startuml
skinparam backgroundColor LightYellow
skinparam state {
StartColor MediumBlue
EndColor Red
BackgroundColor Peru
BackgroundColor<<Warning>> Olive
BorderColor Gray
FontName Impact
}
[*] --> NotShooting
state "Not Shooting State" as NotShooting {
state "Idle mode" as Idle <<Warning>>
state "Configuring mode" as Configuring
[*] --> Idle
Idle --> Configuring : EvConfig
Configuring --> Idle : EvConfig
}
NotShooting --> [*]
@enduml
