I have installed on my machine the tomcat container (also tried with jetty) of the PlantUML server
docker run -d -p 8080:8080 plantuml/plantuml-server:tomcat
and now, when opening http://localhost:8080/ and trying the example from your web page for procedure usage (see below), I am getting an error:
[From string (line 2) ]
@startuml
!procedure msg($source, $destination)
Syntax Error?
---
@startuml
!procedure msg($source, $destination)
$source --> $destination
!endprocedure
!procedure init_class($name)
class $name {
$addCommonMethod()
}
!endprocedure
!procedure $addCommonMethod()
toString()
hashCode()
!endprocedure
init_class("foo1")
init_class("foo2")
msg("foo1", "foo2")
@enduml
---