Activity Diagram

To be able to generate those diagram, you must have Graphviz software installed on your machine in the default directory c:\Program Files\GraphvizX.XX or /usr/bin/dot.

You can have a look here if you have installed Graphviz somewhere else.

Simple Activity

You can use (*) for the starting point and ending point of the activity diagram.

In some occasion, you may want to use (*top) to force the starting point to be at the top of the diagram.

Use --> for arrows.

@startuml

(*) --> "First Activity"
"First Activity" --> (*)

@enduml

Label on arrows

By default, an arrow starts at the last used activity.

You can put a label on an arrow using brackets [ and ] just after the arrow definition.

@startuml

(*) --> "First Activity"
-->[You can put also labels] "Second Activity"
--> (*)

@enduml

Changing 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 Activity"
-right-> "Second Activity"
--> "Third Activity"
-left-> (*)

@enduml

Branches

You can use if/then/else keywords to define branches.

@startuml
(*) --> "Initialization"

if "Some Test" then
  -->[true] "Some Activity"
  --> "Another activity"
  -right-> (*)
else
  ->[false] "Something else"
  -->[Ending process] (*)
endif

@enduml

Unfortunately, you will have to sometimes repeat the same activity in the diagram text:

@startuml
(*)  --> "check input"
If "input is verbose" then
--> [Yes] "turn on verbosity"
--> "run command"
else
--> "run command"
Endif
-->(*)
@enduml

More on Branches

By default, a branch is connected to the last defined activity, but it is possible to override this and to define a link with the if keywords.

It is also possible to nest branches.

@startuml

(*) --> if "Some Test" then

  -->[true] "activity 1"
  
  if "" then
    -> "activity 3" as a3
  else
    if "Other test" then
      -left-> "activity 5"
    else
      --> "activity 6"
    endif
  endif
  
else

  ->[false] "activity 2"
  
endif

a3 --> if "last test" then
  --> "activity 7"
else
  -> "activity 8"
endif

@enduml

Synchronization

You can use === code === to display synchronization bars.

@startuml

(*) --> ===B1=== 
--> "Parallel Activity 1"
--> ===B2===

===B1=== --> "Parallel Activity 2"
--> ===B2===

--> (*)

@enduml

Long activity description

When you declare activities, you can span on several lines the description text. You can also add \n in the description.

You can also give a short code to the activity with the as keyword. This code can be used latter in the diagram description.

@startuml
(*) -left-> "this <size:20>activity</size>
	is <b>very</b> <color:red>long2</color>
	and defined on several lines
	that contains many <i>text</i>" as A1

-up-> "Another activity\n on several lines"

A1 --> "Short activity <img:sourceforge.jpg>"
@enduml

Notes

You can add notes on a activity using the commands note left, note right, note top or

note
bottom

, just after the description of the activity you want to note.

If you want to put a note on the starting point, define the note at the very beginning of the diagram description.

You can also have a note on several lines, using the endnote keywords.

@startuml

(*) --> "Some Activity"
note right: This activity has to be defined
"Some Activity" --> (*)
note left
 This note is on
 several lines
end note

@enduml

Partition

You can define a partition using the partition keyword, and optionally declare a background color for your partition (Using a html color code or name)

When you declare activities, they are automatically put in the last used partition.

You can close the partition definition using a closing bracket }.

@startuml

partition Conductor {
  (*) --> "Climbs on Platform"
  --> === S1 ===
  --> Bows
}

partition Audience LightSkyBlue {
  === S1 === --> Applauds
}

partition Conductor {
  Bows --> === S2 ===
  --> WavesArmes
  Applauds --> === S2 ===
}

partition Orchestra #CCCCEE {
  WavesArmes --> Introduction
  --> "Play music"
}

@enduml

Title the diagram

The title keywords is used to put a title.

You can use title and end title keywords for a longer title, as in sequence diagrams.

@startuml
title Simple example\nof title 

(*) --> "First activity"
--> (*)
@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 activities.

@startuml

skinparam backgroundColor #AAFFFF
skinparam activity {
  StartColor red
  BarColor SaddleBrown 
  EndColor Silver
  BackgroundColor Peru
  BackgroundColor<< Begin >> Olive
  BorderColor Peru
  FontName Impact
}

(*) --> "Climbs on Platform" << Begin >>
--> === S1 ===
--> Bows
--> === S2 ===
--> WavesArmes
--> (*)

@enduml

Octagon

You can change the shape of activities to octagon using the skinparam activityShape octagon command.

@startuml
'Default is skinparam activityShape roundBox
skinparam activityShape octagon

(*) --> "First Activity"
"First Activity" --> (*)

@enduml

Complete example

@startuml
title Servlet Container

(*) --> "ClickServlet.handleRequest()"
--> "new Page"

if "Page.onSecurityCheck" then
  ->[true] "Page.onInit()"
  
  if "isForward?" then
   ->[no] "Process controls"
   
   if "continue processing?" then
     -->[yes] ===RENDERING===
   else
     -->[no] ===REDIRECT_CHECK===
   endif
   
  else
   -->[yes] ===RENDERING===
  endif
  
  if "is Post?" then
    -->[yes] "Page.onPost()"
    --> "Page.onRender()" as render
    --> ===REDIRECT_CHECK===
  else
    -->[no] "Page.onGet()"
    --> render
  endif
  
else
  -->[false] ===REDIRECT_CHECK===
endif

if "Do redirect?" then
 ->[yes] "redirect request"
 --> ==BEFORE_DESTROY===
else
 if "Do Forward?" then
  -left->[yes] "Forward request"
  --> ==BEFORE_DESTROY===
 else
  -right->[no] "Render page template"
  --> ==BEFORE_DESTROY===
 endif
endif

--> "Page.onDestroy()"
-->(*)

@enduml