(Mirror 1)       (Mirror 2)       (Mirror 3)

# Activity Diagram (beta)

Current syntax for activity diagram has several limitations and drawbacks (for example, it's difficult to maintain).

So a completely new syntax and implementation is proposed as beta version to users (starting with V7947), so that we could define a better format and syntax.
Another advantage of this new implementation is that it's done without the need of having Graphviz installed (as for sequence diagrams).

The new syntax will replace the old one. However, for compatibility reason, the old syntax will still be recognized, to ensure ascending compatibility.
Users are simply encouraged to migrate to the new syntax.

## Simple Activity

Activities label starts with `:` and ends with `;`.

Text formatting can be done using creole wiki syntax.

They are implicitly linked in their definition order.

 ```@startuml :Hello world; :This is on defined on several **lines**; @enduml ```

## Start/Stop

You can use `start` and `stop` keywords to denote the beginning and the end of a diagram.
 ```@startuml start :Hello world; :This is on defined on several **lines**; stop @enduml ```

## Conditional

You can use `if`, `then` and `else` keywords to put tests if your diagram. Labels can be provided using parentheses.
 ```@startuml start if (Graphviz installed?) then (yes) :process all\ndiagrams; else (no) :process only __sequence__ and __activity__ diagrams; endif stop @enduml ```
You can use the `elseif` keyword to have several tests :
 ```@startuml start if (condition A) then (yes) :Text 1; elseif (condition B) then (yes) :Text 2; stop elseif (condition C) then (yes) :Text 3; elseif (condition D) then (yes) :Text 4; else (nothing) :Text else; endif stop @enduml ```

## Repeat loop

You can use `repeat` and `repeatwhile` keywords to have repeat loops.
 ```@startuml start repeat :read data; :generate diagrams; repeat while (more data?) stop @enduml ```

## While loop

You can use `while` and `end while` keywords to have repeat loops.
 ```@startuml start while (data available?) :read data; :generate diagrams; endwhile stop @enduml ```
It is possible to provide a label after the `endwhile` keyword, or using the `is` keyword.
 ```@startuml while (check filesize ?) is (not empty) :read file; endwhile (empty) :close file; @enduml ```

## Parallel processing

You can use `fork`, `fork again` and `end fork` keywords to denote parallel processing.
 ```@startuml start if (multiprocessor?) then (yes) fork :Treatment 1; fork again :Treatment 2; end fork else (monoproc) :Treatment 1; :Treatment 2; endif @enduml ```

## Notes

Text formatting can be done using creole wiki syntax.
 ```@startuml start :foo1; note left: This is a note :foo2; note right This note is on several //lines// and can contain HTML ==== * Calling the method ""foo()"" is prohibited end note stop @enduml ```

## Title & Legend

 ```@startuml title this is my title if (condition?) then (yes) :yes; else (no) :no; note right this is a note end note endif stop legend this is the legend endlegend footer dummy footer header this is a long __dummy__ header end header @enduml ```

## Colors

You can use specify a color for some activities.
 ```@startuml start :starting progress; #HotPink:reading configuration files These files should edited at this point!; #AAAAAA:ending of the process; @enduml ```

## Arrows

Using the `->` notation, you can add texts to arrow, and change their color.
 ```@startuml :foo1; -> You can put text on arrows; if (test) then -[#blue]-> :foo2; -[#green]-> The text can also be on several lines and **very** long...; :foo3; else -[#black]-> :foo4; endif -[#gray]-> :foo5; @enduml ```

## Grouping

You can group activity together by defining partition:
 ```@startuml start partition Initialization { :read config file; :init internal variable; } partition Running { :wait for user interaction; :print information; } stop @enduml ```

## Swimlanes

Using pipe `|`, you can define swimlanes.
It's also possible to change swimlanes color.
 ```@startuml |Swimlane1| start :foo1; |#AntiqueWhite|Swimlane2| :foo2; :foo3; |Swimlane1| :foo4; |Swimlane2| :foo5; stop @enduml ```

## Detach

It's possible to remove an arrow using the `detach` keyword.
 ```@startuml :start; fork :foo1; :foo2; fork again :foo3; detach endfork if (foo4) then :foo5; detach endif :foo6; detach :foo7; stop @enduml ```

## SDL

By changing the final `;` separator, you can set different rendering for the activity:
• `|`
• `<`
• `>`
• `/`
• `]`
• `}`
 ```@startuml :Ready; :next(o)| :Receiving; split :nak(i)< :ack(o)> split again :ack(i)< :next(o) on several line| :i := i + 1] :ack(o)> split again :err(i)< :nak(o)> split again :foo/ split again :i > 5} stop end split :finish; @enduml ```

## Complete example

 ```@startuml start :ClickServlet.handleRequest(); :new page; if (Page.onSecurityCheck) then (true) :Page.onInit(); if (isForward?) then (no) :Process controls; if (continue processing?) then (no) stop endif if (isPost?) then (yes) :Page.onPost(); else (no) :Page.onGet(); endif :Page.onRender(); endif else (false) endif if (do redirect?) then (yes) :redirect process; else if (do forward?) then (yes) :Forward request; else (no) :Render page template; endif endif stop @enduml ```