Add null character to %filename() on server (and PicoWeb)

Question

Some plugins (Visual Studio code, Chrome, ...) can use a local version of plantuml or on a web sever. The web server is really faster but has a big issue with %filename(). This version return an empty string on a server and generate error with Title, Caption, ...

@startuml
Title %filename()
actor actor [[{actor}]]
caption %filename()
@enduml

See on PlantUML Server

The workaround is to add a null character after like this:

@startuml
Title %filename() <U+0000>
actor actor [[{actor}]]
caption %filename() <U+0000>
@enduml

Would it be possible to include the null character directly in the %filename() function in server mode? 

Comments

Hello PlantUML team,

Or the opposite (to avoid to add null char...) [That is only a proposal...]:

• Could you allow the common commands (title, caption, header, footer or legend) to accept empty string as argument, and does not produce a 'Syntax Error'?

Example:

@startuml
Title ""
Caption
@enduml

[See on PlantUML server]

Thank for your support,
Regards,
Th.

---

Or better, use the filename just after @startuml like this:

@startuml Thefilename
Title %filename()
actor actor [[{actor}]]
caption %filename()
@enduml

With local version of plantuml, it generate the image in TheFilename.png  (or svg)

In the server version %filename() could return Thefilename

---

Hello Serge and PlantUML team,

For %filename() and filename after @startuml [your Thefilename], see also:

• https://forum.plantuml.net/11628/access-diagram-name-from-preprocessor

Regards,
Th.

---

Hello PlantUML team,

Some news about one of the possibilities to solve this problem

---

With new beta http://beta.plantuml.net/plantuml.jar and on the online server, you can now have:

title ""

This was the easiest to implement.

Tell us if you find issues!

---

Thanks, for other use (caption, etc.) as workaround I create a function:

!function $filename2()
!if (%strlen(%filename())) 
!return %filename()
!else
!return "Generated from web server"
!endfunction

Answer 1

I think the simples solution of the problem are surrounding turned comma. This should work in all required scenarios.

@startuml
Title "%filename()"
actor actor [[{actor}]]
caption "%filename()"
@enduml

Best regards
Helmut