PlantUML Q&A - Recent questions and answers in Question / help

Answered: How to simulate 0.5Hz clock in Timing-diagram

Thu, 28 May 2026 14:04:24 +0000

Hello P.,

From last version v1.2026.5, we can now have:

@startuml
clock clk with period 1
clock clk2 with period 0.5
@enduml

Enjoy,
Regards,
Th.

Answered: Swimlanes overlapping lines when using split

Sun, 10 May 2026 19:45:38 +0000

Hello M.,

In order to answer old request, for that you can use dummy label, as:

@startuml
title something

|#dee4e8|p1|
|#c4c9cd|p2|
|#daf0fe|Backend|

|Backend|
start
    :something;
    if (open) then (yes)
        :generate open data;
        split
            :Mail to p1\nMAIL ID: **3010**; <<#3f3>>
            |p1|
            label d1
            label d2
            :Receive Mail **3010**;
            detach
        split again
            |Backend|
            label d3
            :Mail to p2\nMAIL ID: **3006**; <<#3f3>>
            |p2|
            label d4
            label d5
            :Receive Mail **3006**;
            detach
        end split
    endif
    |Backend|
    :something else; <<#HotPink>>
stop
@enduml

Enjoy,

Regards,
Th.

Answered: Add pictures to participants in sequence diagramm

Fri, 08 May 2026 15:52:15 +0000

Hello J.,

Another solution is to use local sprite or emoji, as:

@startuml
sprite UserRound <svg viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
<g fill="none" stroke="000000" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round">
<path d="M12 21.25C17.1086 21.25 21.25 17.1086 21.25 12C21.25 6.89137 17.1086 2.75 12 2.75C6.89137 2.75 2.75 6.89137 2.75 12C2.75 17.1086 6.89137 21.25 12 21.25Z" ></path>
<path d="M12.1303 13C13.8203 13 15.1903 11.63 15.1903 9.94C15.1903 8.25001 13.8203 6.88 12.1303 6.88C10.4403 6.88 9.07031 8.25001 9.07031 9.94C9.07031 11.63 10.4403 13 12.1303 13Z"></path>
<path d="M6.5 19.11C6.80719 17.8839 7.51529 16.7956 8.51178 16.0179C9.50827 15.2403 10.736 14.818 12 14.818C13.264 14.818 14.4917 15.2403 15.4882 16.0179C16.4847 16.7956 17.1928 17.8839 17.5 19.11"></path>
</g>
</svg>

participant "<$UserRound>" as a
participant "<:1f600:>" as b

a -> b
return
@enduml

See doc. here:

Regards,
Th.

Why can't the old syntax for Activity-Diagram shapes no longer be supported?

Thu, 30 Apr 2026 08:12:34 +0000

We use a lot of activity Diagrams in our projects and need to change them from time to time. Now the old diagrams witch the syntax

 :FooBar>  
 :FooBar< 
 :FooBar|

etc. no longer work since they have instead to be written much longer using

:FooBar; <<StereoType>>

Is it realy such a big issue for the parser that it is not possible to stay compatible to previous versions?

I know the whole new actitivy syntax is marked as beta but it is such a long time already and people are using it - regardless of it being our fault to do so it would be nice if we had some kind of solution without needing to change all existing diagram sources...

How to get the calculated dates from gantt chart?

Wed, 22 Apr 2026 15:30:32 +0000

Hello,

When using the gantt chart, I set the project start date and add the tasks and its dependecies, so the plantuml engine calculates the end's date of these tasks.

How can I get or see these end's date tasks?

Thank you.

Answered: Provide all dates in a file (e.g csv) after gantt chart generation

Wed, 22 Apr 2026 15:25:34 +0000

Hello,

Can you explain a little more how do you extract the calculated dates from plantuml?

I can't view correctly the end's date with weekly printscale.

Answered: PlantUML activity grammar

Wed, 15 Apr 2026 20:02:37 +0000

Hello A.,

All the Internal Regex in order to parse the activity grammar are here:

plantuml/src/main/java/net/sourceforge/plantuml/activitydiagram3/command at master · plantuml/plantuml

Enjoy,

Thank you to share your work if you wish.

Regards,
Th.

Mutually exclusive tasks in Gantt Chart

Fri, 03 Apr 2026 05:14:43 +0000

G'Day,

I'm struggling with what I would have thought would be a simple thing in Gantt charts.

I have two [or more] tasks that are not dependent on each other, but require the same resource, so cannot be worked at the same time, exemplified by the following code:

@startgantt

Project starts 2026-04-06
Saturday are closed
Sunday are closed

[Task A] on {Me:100%} requires 5 days
[Task B] on {Me:100%} requires 3 days
[Task C] on {Me:100%} requires 2 days
[Task D] on {Me:100%} requires 5 days

[Task B] starts at [Task A]'s end
[Task C] starts at [Task A]'s end
[Task D] starts at [Task B]'s end
[Task D] starts at [Task C]'s end

@endgantt

This project could be completed by doing:

Task A, Task B, Task C, and Task D
Task A, Task C, Task B, and Task D
Task A, interleaving Tasks B and C, and Task D

Given that the order of tasks B and C doesn't matter, I'd be happy if the Gantt chart code picked option 1 as it's a valid solution.

What happens, however, is that I apparently clone myself and work both Task B and C concurrently for two days, completing the 15 days work in 13 elapsed days.

This produces the correct result:
[Task B] starts at [Task A]'s end
[Task C] starts at [Task A]'s end
[Task C] starts at [Task B]'s end with #FFFFFF00 link
[Task D] starts at [Task B]'s end
[Task D] starts at [Task C]'s end

Interestingly, this does not produce the correct result, scheduling Tasks C and D concurrently:
[Task B] starts at [Task A]'s end
[Task C] starts at [Task A]'s end
[Task D] starts at [Task B]'s end
[Task D] starts at [Task C]'s end
[Task C] starts at [Task B]'s end with #FFFFFF00 link

One extra invisible link isn't too much of an issue, but as a work-around it doesn't scale well.

Is there any way to enforce the resource constraint without adding extra dependencies?

Thanks,

Mark.

Answered: gantt multiline header: "endheader" not recognized with gantt (@startgantt )

Fri, 20 Mar 2026 13:00:26 +0000

Hello W.,

That is now fixed (observed on v1.2026.3+)

Regards,
Th.

Answered: i want to make my external actor go to the right of the system boundary can u write a plant uml code in draw.io for me?

Mon, 16 Mar 2026 12:08:23 +0000

Hello G.,

Here is a proposal, change 'Passenger' and 'System Administrator' order and add a level for Relationships, as:

@startuml
skinparam actorStyle stickman
left to right direction

' --- Styling ---
skinparam usecase {
    BackgroundColor<<Hub>> #FFCC99
    BackgroundColor<<Technical>> #E1D5E7
    BackgroundColor<<Action>> #FFFFFF
    BackgroundColor<<External>> #F5F5F5
}

' --- Actors (Left Side) ---
actor "System Administrator" as SysAdmin
actor Passenger

' --- System Boundary ---
rectangle "LongThangNaiKorTorMor System" {
    
    (View Station Maps) as UC2
    (Check Train/Bus Schedule) as UC3
    (Top up Travel Card) as UC4
    (View Travel History) as UC5
    (Report Issue) as UC6
    (Generate Payment QR / NFC) as UC_Pay
    (Check Crowd Density) as UC_Crowd
    (Plan Multi-Modal Journey) as UC1

    (Deploy System Updates) as UC13
    (Generate System Reports) as UC7
    (Handle Feedbacks) as UC8
    (API Management) as UC12
    (Manage User Accounts) as UC9
    (Monitor System Health) as UC11
    (Configure GTFS Data) as UC_GTFS

    (Login to Passenger Account) as LoginP <<Hub>>
    (Verify Wallet Balance) as VerifyW <<Hub>>
    (Login to Admin Panel) as LoginS <<Hub>>
    
    (Update Transit Channels) as T1 <<Technical>>
    (Upload Map Media) as T2 <<Technical>>
    (Set Route Milestones) as T3 <<Technical>>
}

' --- Actors (Right Side) ---
' Defining these AFTER the rectangle forces them to the right
actor "Payment Scanner" as Scanner <<External>>
actor "Transit Operator API" as TransitAPI <<External>>

' --- Relationships (Left) ---
Passenger --> UC1
Passenger --> UC2
Passenger --> UC3
Passenger --> UC4
Passenger --> UC5
Passenger --> UC6
Passenger --> UC_Crowd
Passenger --> UC_Pay

SysAdmin --> UC7
SysAdmin --> UC8
SysAdmin --> UC9
SysAdmin --> UC_GTFS
SysAdmin --> UC11
SysAdmin --> UC12
SysAdmin --> UC13

' --- Internal Logic ---
UC_Pay ..> LoginP : <<include>>
UC_Pay ..> VerifyW : <<include>>
UC4 ..> LoginP : <<include>>
UC5 ..> LoginP : <<include>>
UC9 ..> LoginS : <<include>>
UC11 ..> LoginS : <<include>>
UC12 ..> LoginS : <<include>>

UC_GTFS <.. T1 : <<extend>>
UC_GTFS <.. T2 : <<extend>>
UC_GTFS <.. T3 : <<extend>>

' --- Relationships (Right) ---
' Using the syntax "UseCase -- Actor" pushes the actor to the right
UC_Crowd --- TransitAPI
UC1 --- TransitAPI
UC_Pay --- Scanner

@enduml

Enjoy,
Regards,
Th.

in class Diagram ,what does "#--"、“^--”、“x--”、“}--”、“+--” mean

Tue, 24 Feb 2026 07:48:38 +0000

Answered: Class diagram: how to represent deprecated static method

Wed, 18 Feb 2026 19:37:57 +0000

Hello S.,

Could you test with the last snapshot (v1.2025.2+) here:

Releases · plantuml/plantuml

We made a first change.

Enjoy,
Regards,
Th.

Answered: Mismatched and incompatible versions between online server and downloadable jar.

Sun, 15 Feb 2026 11:04:31 +0000

Hello H.,

For that you can download the last snapshot here:

Releases · plantuml/plantuml

Regards,
Th.

Answered: Problem with !include using relative paths in v1.2026.0?

Wed, 28 Jan 2026 16:20:09 +0000

Does you "theme.puml" starts or contains "@startuml" ?

In that case, this issue have been fixed in V1.2026.2beta2 https://github.com/plantuml/plantuml/releases/tag/snapshot

Hope this helps!

Preferred use of qualified name (absolute vs. relative names)

Mon, 26 Jan 2026 09:37:36 +0000

Dear all, it seems that there are different ways to use qualified names (which are not well documented, unless I am mistaken). In the following simple example. I like to declare an association between the classes A and B which are in the packages p1 and p2, respectively.

PlantUML can create a duplicate of a referenced classifier, since it interprets a qualified name as a relative path unless it is prefixed with a dot or the first segment of the qualified name is already known. See below for an example. Is there a preference to use qualified names?

@startuml
' does not work: p2 is interpreted as subpackage of p1, B is duplicated
package p1 {
class A { }
A -- p2.B
}

package p2 {
class B { }
}
@enduml

@startuml
' forward declaration of p2, works
package p2 {}

package p1 {
class A { }
A -- p2.B
}

package p2 {
class B { }
}
@enduml

@startuml
' absolute qualified names using a preceding dot

package p1 {
class A { }
A -- .p2.B
}

package p2 {
class B { }
}
@enduml

@startuml
' enclosing with single root, works

package root {
package p1 {
class A { }
A -- root.p2.B
}

package p2 {
class B { }
}
}
@enduml

Answered: why %json_key_exists doesn't protect from missing keys?

Thu, 22 Jan 2026 19:13:05 +0000

Thank K.for the report.

FYI, that is now fixed from V1.2026.0:

https://github.com/plantuml/plantuml/releases/latest

Regards,
Th.

Answered: "hide class" is not working?

Fri, 16 Jan 2026 20:32:26 +0000

I had a similar issue my workaround was adding a tag to all classes, hide all classes based on the tag and then show the class(es) you actually want to see like

class A $OXO
class B $OXO

hide $OXO

show B

Answered: Is it possible to change the shape (diamond->rectangle) of a concise signal in a timing diagram?

Fri, 16 Jan 2026 12:18:46 +0000

Hello P., and X.,

See new rectangle keyword from V1.2025.10 with:

Rectangles instead of HexaShape in timing diagram · Issue #2409 · plantuml/plantuml

Regards,
Th.

Answered: Define spacing between sequence-diagram columns

Wed, 14 Jan 2026 12:01:20 +0000

See this new enhancement (on V1.2025.9)

sequence diagram: allow message to span beyond the involved participants · Issue #2386 · plantuml/plantuml

Enjoy,
Regards,
Th.

Answered: Uneven spacing between box items

Wed, 14 Jan 2026 11:56:35 +0000

Hello A.,

For that you can change 'Padding' parameter with:

skinparam ParticipantPadding 50
skinparam BoxPadding 20

See doc. here:

https://plantuml.com/sequence-diagram#33cee7c2521befd3

Enjoy,
Regards,
Th.

Answered: Can I use UML notes (comments) notation in PlantUML according to the UML standard specification?

Tue, 13 Jan 2026 06:27:49 +0000

Oh, thank you very much! This helped me solve my issue with a workaround!

I'll put my adjustments here using the provided link as a basis.

Kind regards!

@startuml

hide circle

skinparam class {
AttributeIconSize 0
BackgroundColor white
}

skinparam note {
BackgroundColor white
' According to the UML Spec.
}

' All connections to notes use dashed lines

title "UML notes/comments"

' Source: adapted from https://github.com/plantuml/plantuml-server/issues/384

package workaround-for-uml-strict-compatibility {
class a_class as "AClass" {
- anAttribute : float
}

note as floating_note
This note isn't
connected to
any element.
end note

note as note_to_element
This note is
connected to
a classifier.
end note

/'
Connection workaround: two hidden connections
before and after the actual connection to
make it point straight. One of the hidden ones
can be removed for a non-straight connection.
'/
note_to_element .r[hidden]. a_class /' Layout purposes '/
note_to_element .. a_class
note_to_element .[hidden]. a_class /' Layout purposes '/

class another_class as "AnotherClass"
another_class <|-- a_class

note as note_to_link
This note is
connected to
a link.
end note

/'
Connection workaround with an actual connection
and a single hidden connection.
'/

note_to_link . (another_class, a_class)
note_to_link .[hidden]. a_class /' Layout purposes '/
}
@enduml

I think the yellow background comes from older UML tools.

Here's the link with the result.

How to increase heap size for plantuml-server running in container?

Tue, 06 Jan 2026 17:12:05 +0000

I am running plantuml-server (jetty) in a container, and I am getting OutofMemoryError: java.heap.space" for one larger diagram.

I tried increasing the heap by adding

```
environment:
- JAVA_OPTIONS=-Xmx512m

```

to my docker-compose file. But that does not seem to have any effect?

Answered: Source code documentation

Mon, 05 Jan 2026 17:20:54 +0000

AI generated doc might help

plantuml/plantuml | DeepWiki

How does the new syntax of activity diagrams achieve the pointing of corresponding arrows?

Sat, 03 Jan 2026 15:51:15 +0000

The old syntax of activity diagrams achieves arrow conversion through keywords such as down, but the new syntax does not support the down keyword.

-down-> (default arrow)
-right-> or ->
-left->
-up->

As shown in the activity diagram of the new grammar below, how can the pointing of arrows be achieved：

@startuml
start
:"First Activity";
:"Second Activity;
:"Third Activity";
stop
@enduml

Answered: Avoid multiple PlantUML backwards arrows

Mon, 22 Dec 2025 18:32:45 +0000

Hi B.,

From:

Currently that is not yet possible to merge all 'no' arrows: That is a wanted feature...

But here is a proposal with "label/goto" (but with one cross):

@startuml
start
  while (Work to do?) is (found)
    if (Question 2 ?) then (no)
    label sp;
    label lab;
    (yes ) elseif (Question 3 ?) then (no)
    label sp;
    goto lab;
    (yes ) elseif (Question 4 ?) then (no)
    label sp;
    goto lab;
    (yes ) elseif (Question 5 ?) then (no)
    label sp;
    goto lab;
    else (yes )
      :Success;
      label sp;
      label sp;
      label sp;
      break;
    endif
  endwhile (no more)
end
@enduml

If that can help,...

Regards,
Th.

Answered: Can I display diamond name in class diagram?

Thu, 18 Dec 2025 16:17:54 +0000

Hi S.,

Could you test:

@startuml
class A
class B

A --* "diamond name" B
@enduml

Regards,
Th.

Answered: Header one color, body different color

Fri, 05 Dec 2025 12:08:48 +0000

Hello A.,

To complete the Serge's answer, you can also use "object", "map" or "json".

See examples here:

Enjoy,
Regards,
Th.

In Network Diagrams (Nwdiag) is it possible to style the address default font background color, without using HTML tags?

Thu, 27 Nov 2025 15:20:58 +0000

Hi,

Is it possible to set the default background color of the text of "address", in order to avoid the overlapping of text and lines? I tried to set a style using :

<style>

nwdiagDiagram {

 arrow {

 ' FontXXX only for address

 BackGroundColor #plum

 }

}

</style>

But it does not seem to work. The alternative would be using HTML tags for every address:

nwdiag {

 network internal {
 address = "<back:plum>172.x.x.x/24";

 web01 [address = "<back:plum>172.x.x.1"];

 }

}

but I wonder if there is another way I'm not aware of.

Thank you in advance!

How to Set Default Zoom Level for Diagrams in PlantUML IDEA Plugin?

Thu, 27 Nov 2025 14:11:23 +0000

I am using the PlantUML plugin within IntelliJ IDEA. My computer screen has a 3840×2160 resolution (4K). Because of this, every time I open a sequence diagram, the image is displayed at a very small default zoom level, forcing me to zoom in manually each time to see it clearly.

My question is: Is there a way to configure the plugin to use a larger default zoom level when opening diagrams, so that they are easily readable from the start?

Thank you for your help.

Can resource allocation in a gantt chart be scaled on a weekly or monthly base?

Mon, 24 Nov 2025 14:23:29 +0000

I use a simple gantt chart with resources. Here a easy example from the website:

@startgantt
project starts 2025-10-01
printscale daily
[Task1] on {Alice} requires 30 days
[Task2] on {Bob:50%} requires 2 days
then [Task3] on {Alice:25%} requires 1 days
@endgantt

when I switch the printscale to weekly the resource calculation gives me the sum of the resources.

I know it's correct, but not intuitive to me. I would prefer a mean value for the week.

Is there a way to make this work?

Thanks!

Why this don't work.

Fri, 21 Nov 2025 20:07:05 +0000

File: govite_rpc_diagram.puml

@startuml
namespace rpc {
 class "API" << (S,Aquamarine) >> {
 + Namespace string
 + Version string
 + Service interface{}
 + Public bool

 }
 class "BatchElem" << (S,Aquamarine) >> {
 + Method string
 + Args []interface{}
 + Result interface{}
 + Error error

 }
 class "Client" << (S,Aquamarine) >> {
 - idCounter uint32
 - connectFunc func(context.Context) (net.Conn, error)
 - isHTTP bool
 - writeConn net.Conn
 - close chan struct{}
 - didQuit chan struct{}
 - reconnected chan net.Conn
 - readErr chan error
 - readResp chan []*jsonrpcMessage
 - requestOp chan *requestOp
 - sendDone chan error
 - respWait map[string]*requestOp
 - subs map[string]*ClientSubscription

 - nextID() json.RawMessage
 - newMessage(method string, paramsIn ...interface{}) (*jsonrpcMessage, error)
 - send(ctx context.Context, op *requestOp, msg interface{}) error
 - write(ctx context.Context, msg interface{}) error
 - reconnect(ctx context.Context) error
 - dispatch(conn net.Conn)
 - closeRequestOps(err error)
 - handleNotification(msg *jsonrpcMessage)
 - handleResponse(msg *jsonrpcMessage)
 - read(conn net.Conn) error
 - sendHTTP(ctx context.Context, op *requestOp, msg interface{}) error
 - sendBatchHTTP(ctx context.Context, op *requestOp, msgs []*jsonrpcMessage) error

 + SupportedModules() (map[string]string, error)
 + Close()
 + Call(result interface{}, method string, args ...interface{}) error
 + CallContext(ctx context.Context, result interface{}, method string, args ...interface{}) error
 + BatchCall(b []BatchElem) error
 + BatchCallContext(ctx context.Context, b []BatchElem) error
 + EthSubscribe(ctx context.Context, channel interface{}, args ...interface{}) (*ClientSubscription, error)
 + ShhSubscribe(ctx context.Context, channel interface{}, args ...interface{}) (*ClientSubscription, error)
 + Subscribe(ctx context.Context, namespace string, channel interface{}, args ...interface{}) (*ClientSubscription, error)

 }
 class "ClientSubscription" << (S,Aquamarine) >> {
 - client *Client
 - etype reflect.Type
 - channel reflect.Value
 - namespace string
 - subid string
 - in chan json.RawMessage
 - quitOnce sync.Once
 - quit chan struct{}
 - errOnce sync.Once
 - err chan error

 - quitWithError(err error, unsubscribeServer bool)
 - deliver(result json.RawMessage) bool
 - start()
 - forward() (error, bool)
 - unmarshal(result json.RawMessage) (interface{}, error)
 - requestUnsubscribe() error

 + Err() chan error
 + Unsubscribe()

 }
 interface "Error" {
 + Error() string
 + ErrorCode() int

 }
 interface "ErrorWithId" {
 + Id() interface{}

 }
 class "StdIOConn" << (S,Aquamarine) >> {
 + Read(b []byte) (int, error)
 + Write(b []byte) (int, error)
 + Close() error
 + LocalAddr() net.Addr
 + RemoteAddr() net.Addr
 + SetDeadline(t time.Time) error
 + SetReadDeadline(t time.Time) error
 + SetWriteDeadline(t time.Time) error

 }
 class "Subscription" << (S,Aquamarine) >> {
 - namespace string
 - err chan error

 + ID ID

 + Err() chan error

 }
 class "WebSocketCli" << (S,Aquamarine) >> {
 - u *url.URL
 - c *websocket.Conn
 - srv *Server
 - closed chan struct{}
 - nextConnTime time.Time

 + Srv(c *websocket.Conn) error
 + Close()
 + Handle()

 }
 class "callback" << (S,Aquamarine) >> {
 - rcvr reflect.Value
 - method reflect.Method
 - argTypes []reflect.Type
 - hasCtx bool
 - errPos int
 - isSubscribe bool

 }
 class "callbackError" << (S,Aquamarine) >> {
 - message string

 + ErrorCode() int
 + Error() string

 }
 class "executePanicError" << (S,Aquamarine) >> {
 + ErrorCode() int
 + Error() string

 }
 class "httpConn" << (S,Aquamarine) >> {
 - client *http.Client
 - req *http.Request
 - closeOnce sync.Once
 - closed chan struct{}

 - doRequest(ctx context.Context, msg interface{}) (io.ReadCloser, error)

 + LocalAddr() net.Addr
 + RemoteAddr() net.Addr
 + SetReadDeadline( time.Time) error
 + SetWriteDeadline( time.Time) error
 + SetDeadline( time.Time) error
 + Write( []byte) (int, error)
 + Read(b []byte) (int, error)
 + Close() error

 }
 class "httpReadWriteNopCloser" << (S,Aquamarine) >> {
 + Close() error

 }
 class "invalidMessageError" << (S,Aquamarine) >> {
 - message string

 + ErrorCode() int
 + Error() string

 }
 class "invalidParamsError" << (S,Aquamarine) >> {
 - message string

 + ErrorCode() int
 + Error() string

 }
 class "invalidRequestError" << (S,Aquamarine) >> {
 - message string
 - id interface{}

 + ErrorCode() int
 + Error() string
 + Id() interface{}

 }
}
"__builtin__.int" #.. "rpc.CodecOption"
"__builtin__.string" #.. "rpc.ID"
"rpc.map[string]*callback" #.. "rpc.callbacks"
"rpc.map[string]*callback" #.. "rpc.subscriptions"
"rpc.map[string]*service" #.. "rpc.serviceRegistry"
"rpc.Error" *-- "rpc.ErrorWithId"
"io.Reader" *-- "rpc.httpReadWriteNopCloser"
"io.Writer" *-- "rpc.httpReadWriteNopCloser"

"rpc.Error" <|-- "rpc.callbackError"
"rpc.Error" <|-- "rpc.executePanicError"
"rpc.Error" <|-- "rpc.invalidMessageError"
"rpc.Error" <|-- "rpc.invalidParamsError"
"rpc.Error" <|-- "rpc.invalidRequestError"
"rpc.ErrorWithId" <|-- "rpc.invalidRequestError"
"rpc.ServerCodec" <|-- "rpc.jsonCodec"
"rpc.Error" <|-- "rpc.jsonError"
"rpc.Error" <|-- "rpc.methodNotFoundError"
"rpc.ErrorWithId" <|-- "rpc.methodNotFoundError"
"rpc.Error" <|-- "rpc.shutdownError"

@enduml

PS U:\UMLExperiment> java -Xmx2048m -jar G:\Tools\PlantUML\plantuml-mit-1.2025.10.jar govite_rpc_diagram.puml
Warning: no image in govite_rpc_diagram.puml
PS U:\UMLExperiment>

Hide the diagram code from readers of the document who do not have PlantUML ADD-in

Wed, 19 Nov 2025 09:46:35 +0000

After creating my diagrams with PlantUML, I hide the code using the "Hide PlantUML" button and save the document. However, when a reader who does not have PlantUML add-in opens the document, the code is still visible. I expected the code to be hidden and not readable. Is there a solution for this?

Answered: Grok3 building filez from scratch, with many "Type" errors to 2020 Pl. verzion. where are templates online? tkz

Tue, 11 Nov 2025 14:32:08 +0000

Perhaps if you care to formulate your question in a way that can be parsed and without abbreviating every other word, people may care to help you.

What's Xai, a Supercomputer, and Templates? Are you trying to teach a LLM to generate PlantUML diagrams?

Answered: Link to pdf guide for older version

Tue, 11 Nov 2025 14:27:47 +0000

Find the date of the jar you use
Then go to the wayback machine https://web.archive.org/web/20240601000000*/https://pdf.plantuml.net/PlantUML_Language_Reference_Guide_en.pdf and pick a version (the PDF has been archived 59 times from 2019 to 2025)

Answered: Participant - custom images

Tue, 11 Nov 2025 14:23:16 +0000

Well, plantuml-1.2025.8-javadoc.jar is a javadoc not the executable jar.

Answered: Keep getting Error: 520

Tue, 11 Nov 2025 09:42:59 +0000

What's the diagram that causes this error? This SVG diagram displays ok:

https://www.plantuml.com/plantuml/svg/SoWkIImgAStDuNBAJrBGjLDmpCbCJbMmKiX8pSd9vt98pKi1IW80

Answered: Unable to convert Ditaa diagram to png

Tue, 11 Nov 2025 09:40:41 +0000

The diagram works ok on planttext, which runs version 1.2025.10 (Nov 04).

Try upgrading?

Answered: Is someone have experience about encode uml script with javscript or phyton code not in online server?

Tue, 11 Nov 2025 09:36:59 +0000

@Potherca gives a good answer. But I think you'd invoke plantuml.jar from n8n? Then you don't need any of the implementations in a different language, this is a key sentence:

> You can use -encodeurl or -decodeurl in the command line flags to encode or decode the text.

If you will link to plantuml as a library, then you should find the Java method that encodes.

Answered: create DOT diagrams

Mon, 10 Nov 2025 09:55:08 +0000

Hello,

Your question is not very clear, but you can see this topic

Answered: Make separate formatting for each `box` in Sequence_Diagram

Sun, 26 Oct 2025 14:09:52 +0000

you could try something like

BR Helmut

Does PlantUML online server no longer support `http:` image references?

Sat, 25 Oct 2025 16:21:38 +0000

The C4 Readme contains some samples with images referenced via `http:` instead of `https:`.
Previously, the old online server displayed these images without any problems.
The new/current online server reports a "Cannot decode: http://...." error. Is this intentional?

https://www.plantuml.com/plantuml/uml/bP91RzGm48Nl_XL3L45MsYP5XSkAe5PB1KWBMwL572itddKjENPaEvGLuhypjfTi3d3OKvonvvltddtb0tTXx3LxeKodHu7m5CBWLtNj-7CbLNWQ7qUFhhCce0bLP_jwqDp4ddCVX5QFzVhD-MqiVVkogNlk0pegFQofWok3hXeYdxtAfo7IVAg1m1qTyE07fm92aRQAevHtThTJ7TQfNXyRtpF6heLeKTzpMHP_zHHBE0luCwojjgufpgxRTllzORtTRDkufMdMVxQoWAPGlLn5_wjwCfaSQoljPJKO-SjtN6DpKLt-JaYKQCJToTslPzttfBWfA5zlDK9mIafqA8e5OxTas9eo6b_cT40wEmuWbAS9UnJmJ3S4_93Wt4hEaY1ikeYoowj4cwePaPG9u4P05pEYzNP0yvbQL3VdljnPBOYGhRojBfRfV2CTtyTnTtiVi2zz-j2S_7_GQK3rNE99aKTeY_gGmiIbKe9c8fG_58V0fLz4U5mqntUnc06c3EQCoQhvbzTawnEzbytDnvkl7ye5kq8Z2Fm7

The issue is related to PlantUML online server no longer(?) supports http: image references (replace with https:) · Issue #405 · plantuml-stdlib/C4-PlantUML

Thank you and best regards
Helmut

Answered: Low quality render of scaled diagrams with transparent background using PlantUML online server

Sat, 18 Oct 2025 13:34:03 +0000

Thanks for the report.
This should be fixed with release V1.2025.9

Tell us if it's not working for you!

Answered: Timing Diagram participant/player title style color size

Thu, 16 Oct 2025 09:28:55 +0000

Hello N.,

Here is a first global proposal, with style, like:

@startuml
<style>
timingDiagram {
  FontStyle plain
  FontColor blue
  FontSize 10
  concise, robust, timeline {
    FontStyle bold
    FontColor #3
  }
}
</style>

clock   "Clock_0"   as C0 with period 50
clock   "Clock_1"   as C1 with period 50 pulse 15 offset 10
binary  "Binary"  as B
concise "Concise" as C
robust  "Robust"  as R
analog  "Analog"  as A

@0
C is Idle
R is Idle
A is 0

@100
B is high
C is Waiting
R is Processing
A is 2

@150
R is Waiting
A is 1
@enduml

Enjoy,
Regards,
Th.

Two workers on one task starting at different times

Wed, 15 Oct 2025 16:17:51 +0000

I have a question similar to

https://forum.plantuml.net/18397/gantt-how-handle-resource-starts-terminates-specific-date

One worker is working on Job-1.

Once he finished that, he will start Job-2.

A second worker will start on Job-2 while worker one is still on Job-1.

@startgantt
project starts the 2025/10/01
saturday are closed
sunday are closed

[Job-1] as [J1] on {BKI} lasts 13 days
[Job-2] as [J2] lasts 9 days
[J2] on {BKI} starts after [J1]'s end
[J2] on {AKI} starts at 2025-10-15

@endgantt

I came up with the following, but it requires manual adjustment of the workload.

I'd rather prefer to start Job-2 on 2025-10-15 and add resource BKI once Job-1 is finished.

@startgantt
project starts the 2025/10/01
saturday are closed
sunday are closed

[Job-1]   as [J1] on {BKI} lasts 13 days
[Job-2]   as [J2a] lasts 3 days
[Job-2]   as [J2b] lasts 6 days
[J2a] on {BKI} starts after [J1]'s end
[J2b] on {AKI} starts at 2025-10-15

@endgantt

Answered: In WBS diagrams generated by plantuml, can an additional connection be made directly from 1st box to 3rd box?

Wed, 24 Sep 2025 20:50:43 +0000

Hello A.,

Here is a possible (funny) workaround:

@startwbs
* R
** Level 1
*** L 2
**** L3
**** L3
***_ \_
**** L3
**** L3
@endwbs

Regards,
Th.

Answered: How do I use themes in the eclipse plugin

Wed, 24 Sep 2025 10:37:13 +0000

Hello A.,

What theme are you going to talk about?

If you are talking about the theme of plantuml, you can use:

!theme amiga

Eclipse PlantUML view states "Cannot find style sysmic" in red text

Wed, 17 Sep 2025 17:21:01 +0000

I'm new to Eclipse. I have followed the instructions in the ReadME but when I select show view PlantUML I get a message this is an old version and a "Cannot find style sysmic". It was working until it came up with the error that it was 1229 days old, so I updated, and still get the error.

But now have in green on black image:

PlantUML 1.2024.5

This version of PlantUML is 479 days old, so you should

consider upgrading from https://plantUML.com/download

[From string (line 2) ]

@startuml

skin sysmic

Cannot find style sysmic

Preferences state PlantUML installation seems OK, File generation OK. Help!

Can I hide the closed days or move them behing the task in Gantt?

Wed, 17 Sep 2025 16:10:39 +0000

The closed days are shown on top of the tasks and cut it in a very ugly way, especially in bigger scales (monthly, quarterly, yearly).

Is there a way to move them behind the tasks (change the z-order)? Or maybe hide them in big project scales?

I thought I could export it as svg and bring the task to the front. But the task is really cut in smaller rectangles!

@startgantt

printscale quarterly zoom 5
saturday are closed
sunday are closed

project starts 2025-10-01

[Task1] lasts 55 days

[Task2] lasts 85 days and starts at [Task1]'s end

@endgantt

//www.plantuml.com/plantuml/png/NSwn2i8m4CRn_PxYsvmARI3Ws8Tm4uSZEKIDYUOkGtrwGsqNbnj-yFsvMOshNJcR4RtgBPi6Je9twomrBVYKyeGdPMiryWAkWf2AIYHj-Kzwejmb6DQimetE3zCuZ1FH-SJwc2v8hARm7dsh6xkTZpy6vxWtsB1D3mh9aMZkTttv2m00

Most of the images-links are not correct resolved

Thu, 11 Sep 2025 16:44:16 +0000

If I open ex. the README.md of the stdlib (plantuml-stdlib/README.md at master · plantuml/plantuml-stdlib) or the Themes.md of the C4-PlanrUML C4-PlantUML/Themes.md at master · plantuml-stdlib/C4-PlantUML then most of the images are not correct displayed or invisible (if I have no alternative text). In my extended brach I added an alternative text that all not correct resolved images are shown too C4-PlantUML/Themes.md at extended · kirchsth/C4-PlantUML

How can I avoid the broken links/images?

Thank you and best regards
Helmut

PS.: one alternative would be the PlantUML Editor Online - Free & Fast UML Diagram Tool | PlantText server, but this server does not have the last PlantUML release

Activity Diagram with swimlanes and fork: how to disable horizontal shift

Thu, 11 Sep 2025 14:36:04 +0000

Hi there,

I'm having trouble with the width of swimlanes and the horizontal positioning / vertical alignment of boxes therein. The activities should be vertically aligned and no space should be wasted. How could this be achieved?

Thanks for any hint.

@startuml
|P1|
|P2|
|P3|
|P4|
|P5|
|P1|
start
:Do1;
|P2|
:Do2-is-something-really-long;
|P5|
if (Cond1?) then (ok)
|P2|
:Do3-is-longer;
|P1|
:Do4;
floating note right
Comm1
end note
|P5|
:Do5-is-longer-too;
|P1|
:Do6;
:Do7;
fork
|P2|
:Do8-is-something;
:Do9-is-another-thing;
fork again
|P3|
:Do10;
:Do11;
fork again
|P5|
:Do12-leads-to-more-and-more-width;
end fork
|P4|
:Do13;
|P5|
:Do14;
else (not ok)
stop
endif
stop
@enduml