State Diagram

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

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

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

setting arrow direction in UML state diagram

You can shorten the arrow by using only the first character of the direction (for example, -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.

You can define specific color and fonts for stereotyped states.

@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

changing fonts and colors of UML state diagram