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:

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.

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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:

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

Written with PlantUML 8051.

Original blog post

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]%.

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First we use the command line option -checkversion for an out-of-date version:

We update our PlantUML and run the command again:

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

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.

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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.

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PlantUML has a fun command to create a Sudoku puzzle. We must use sudoku in our PlantUML definition and a random puzzle is generated. We can even give a seed value for a given Sudoku so it is generated again.

In the following example PlantUML definition we use the sudoku command:

We create a PNG file with PlantUML and we get the following result:

To regenerate the same Sudoku we must use the seed value cinnld556e0o:

Written with PlantUML 8048.

Original blog post

With PlantUML we can include external files in our definition with the !include directive. We specify the file name and the content is included in our PlantUML definition. The included file can also have multiple @startuml ... @enduml sections and we can refer to individual sections with the !include directive. We must append to the include file name an exclamation mark (!) followed by either a number or identifier. If we use a number we specify which section we want to include, where section are numbered starting from 0. So to get the second section from a file commons.puml we would write !include commons.puml!1. Alternatively we can use identifiers in the include file. We append to @startuml an identifier as (id=idValue). Then from the definition that is including the file we refer to the identifier after an exclamation mark (!). If our included file commons.puml has a section with id user then we would include it as !include commons.puml!user.

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To change the styling of our generated diagrams with PlantUML we can use the skinparam command. We can set for example font size, style, color, background colors and much more. We can change the style for a specific element or for the whole diagram. We can even set specific styling options for stereotypes. The settings for the stereotype are then applied to all elements in our diagram with that stereotype. We must append <<stereotype name>> to the skin parameter name.

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When we write a PlantUML definition the generated graphical diagram is laid out by PlantUML. In a previous post we learned how to move elements using the length of the connection. But we can also use a together block with all elements that should be at the same level. PlantUML will try to keep the elements together when the diagram is drawn.

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By default elements in a PlantUML generated diagram have shadows. To disable shadows we must set the skin parameter shadowing to the value false. PlantUML will then not create shadows on elements.

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