PlantUML Pleasantness: Get PlantUML Definition From PNG

When we generate a PNG version of our PlantUML definition the original definition is stored in the PNG image. We can extract the definition using the command line option -metadata. We need to provide the PNG file and in the output we see the original PlantUML definition.

The following PNG image (activity.png) is created with PlantUML:

Next we run PlantUML from the command line using the option -metadata:

$ java -jar plantuml.jar -metadata activity.png
------------------------
activity.png

@startuml

' Make a dashed line, alternative syntax for ..>
(*) -[dashed]-> "Write outline"

' Make line bold and use color code
"Write outline" -[bold,#008000]-> "Find example"

' Only change the color
"Find example" -[#ff00ff]-> "Write blog"

' Order of line style and color can be reversed
"Write blog" -[#6666ff,dashed]-> "Publish"

' Use dotted line style
"Publish" -[dotted]-> (*)

@enduml

PlantUML version 8051(Thu Dec 01 18:52:05 CET 2016)
(GPL source distribution)
Java Runtime: Java(TM) SE Runtime Environment
JVM: Java HotSpot(TM) 64-Bit Server VM
Java Version: 1.8.0_112-b16
Operating System: Mac OS X
OS Version: 10.12.1
Default Encoding: UTF-8
Language: en
Country: US

------------------------
$

At the top we see the section @startuml..@enduml with the PlantUML syntax that was used to generate the PNG image.

Written with PlantUML 8051.

PlantUML Pleasantness: Change Line Style And Color

We can change the line style and color when we "draw" the line in our PlantUML definition. We must set the line style and color between square brackets ([]). We can choose the following line styles: bold, plain, dotted and dashed. The color is either a color name or a hexadecimal RGB code prefixed with a hash (#).

In the following example activity diagram we apply different styles and colors to the lines:

@startuml

' Make a dashed line, alternative syntax for ..>
(*) -[dashed]-> "Write outline"

' Make line bold and use color name
"Write outline" -[bold,#green]-> "Find example"

' Only change the color with hexadecimal RGB code
"Find example" -[#ff00ff]-> "Write blog"

' Order of line style and color can be reversed
"Write blog" -[#6666ff,dashed]-> "Publish"

' Use dotted line style
"Publish" -[dotted]-> (*)

@enduml

When we generate the activity diagram we see the different line styles and colors:

Written with PlantUML 8051.

PlantUML Pleasantness: Using Current Date

In PlantUML we can use the special variable %date% to get the current date and time. The default format shows day of the week, date, time and timezone. We can change the date format by specifying our format with the Java SimpleDateFromat symbols. For example to only get the hours and minutes we would write %date[HH:mm]%.

In the following example we use the %date% variable as is and with a custom format:

@startuml
' Use %date% to get date diagram is generated.
title Sample with date - %date%

' We can use Java SimpleDateFormat options
' to format the date. In this example we
' only want the day-month-year of the date.
footer Generated on %date[dd-MM-yyyy]%
@enduml

When we generate a graphical representation we get the following result:

Written with PlantUML 8051.

PlantUML Pleasantness: Check If PlantUML Is Up To Date

With the command line option -checkversion we can see if we have the latest PlantUML version. The command prints to the console our current PlantUML version and latest version that is available. Inside a PlantUML definition we can use the command checkversion and generate for example a PNG image with information about our PlantUML version and the latest version that can be downloaded.

First we use the command line option -checkversion for an out-of-date version:

$ plantuml -checkversion
PlantUML version 8048 (Thu Sep 29 19:04:02 CEST 2016)

Last available version for download : 8051

A newer version is available for download.
$

We update our PlantUML and run the command again:

$ plantuml -checkversion
PlantUML version 8051 (Thu Dec 01 18:52:05 CET 2016)

Last available version for download : 8051

Your version is up to date.
$

Now we use a PlantUML definition so we can generate a graphical representation of the information.

@startuml
checkversion
@enduml

First we use the older version of PlantUML to generate a PNG image:

Next we use the latest version that is available:

Written with PlantUML 8051.

PlantUML Pleasantness: Generate Graphical Version Information

If we want to know which version of PlantUML we are using we can use the command line option -version. PlantUML will print the version and also some extra information like the machine name, memory and more. But we can also create a PlantUML definition with the command version and we can transform it to a graphical presentation like a PNG image. This can be handy if we use PlantUML in an environment like Asciidoctor with diagram support and we want to know which version of PlantUML is used.

In our first example we run PlantUML from the command line and use the -version option:

$ plantuml -version
PlantUML version 8051 (Thu Dec 01 18:52:05 CET 2016)
(GPL source distribution)
Java Runtime: Java(TM) SE Runtime Environment
JVM: Java HotSpot(TM) 64-Bit Server VM
Java Version: 1.8.0_112-b16
Operating System: Mac OS X
OS Version: 10.12.1
Default Encoding: UTF-8
Language: en
Country: US
Machine: mrhaki-laptop-2015.fritz.box
PLANTUML_LIMIT_SIZE: 4096
Processors: 8
Max Memory: 3,817,865,216
Total Memory: 257,425,408
Free Memory: 249,050,832
Used Memory: 8,374,576
Thread Active Count: 2

The environment variable GRAPHVIZ_DOT has been set to /usr/local/bin/dot
Dot executable is /usr/local/bin/dot
Dot version: dot - graphviz version 2.38.0 (20140413.2041)
Installation seems OK. File generation OK
$

In the second example we create a file with the following PlantUML definition:

@startuml
version
@enduml

When we generate a PNG from this definition we get the following result:

Written with PlantUML 8051.