PlantUML has a built-in icon set we can use in our diagram definitions. The icon set is open source icon set OpenIconic. We refer to an icon using the syntax <&iconName>.We can use an icon everywhere where we can use text in our diagrams.

In the following example we use different icons in different places:

PlantUML supports sprites to be used in diagrams. A sprite is text encoded monochrome graphic we can reference using the syntax <$spriteName>. The sprite is defined using hexadecimal values. We can define a set of hexadecimal values to create our sprite, but we can also generate the correct values from for example a PNG image.

We start with a simple example where we create a small triangle using hexadecimal values:

In a previous post we learned how to use a together block to keep elements together. We can also layout elements in a different way: using hidden lines. We define our elements and by using the keyword [hidden] in our line definition the elements are layout as if there was a line, but we don’t see it. This gives us great flexibility on how we layout our elements.

In the following sample we first have a PlantUML definition where we rely on the default layout:

We have a lot of ways to customize our PlantUML diagrams. We can change the colors and we can even set gradients as color. A gradient has two colors and a direction. The direction of the gradient is set by the separator between the two colors. We can use the following separators to set the gradient direction:

If a class implements the Closeable interface Groovy adds the withCloseable method to the class. The withCloseable method has a closure as argument. The code in the closure is executed and then the implementation of the close method of the Closeable interface is invoked. The Closeable object is passed as argument to the closure, so we can refer to it inside the closure.

In the following example we have two objects that implement the Closeable interface. By using withCloseable we know for sure the close method is invoked after all the code in the closure is executed:

When we define a list in Asciidoctor we usually have a list item that is a paragraph. But if we want to have a block as list item we need to add an extra element to make sure the block is parsed correctly as list item. Because a list item starts with a . or a * at the beginning of a line and a block also is defined on the beginning of the line, we must add the extra element. Together with the list item continuation (+) we can have a list with blocks.

In the following example we define a numbered list with three listing blocks:

PlantUML has some features that come from the underlying software to create diagrams. Graphviz is used by PlantUML and we can use Graphviz features in our PlantUML diagrams. For example we can align multi-line text of labels to be either center (default), left or right aligned using a Graphviz feature. When we want to text to be center aligned we simply use the new-line character \n. If we want to have our text left aligned we use \l instead of \n. And to right align the text we use \r.

In the following example we have three labels that are center, left and right aligned:

Normally if we type an URL in Asciidoctor that starts with a scheme Asciidoctor knows about, the URL is turned into a hyperlink. The following schemes are recognized by Asciidoctor:

With Asciidoctor markup we can position images in our document. We can even float images, so text can next to an image, inside only below or about the image. We can also define multiple images to float, so the images are displayed on the same line next to each other. Any text that follows these images is also displayed next to the images. If we want only to have floating images, but the text starting under the images we can place the images inside an open block and assign the block the role float-group.

In the next example we first define three images that all have roles to float left. In the second part we group these images using the role float-group, so the text will not be displayed next to the images, but under the images:

In a previous post we learned how to use data in CSV and DSV format. Recently we can also include tab separated values (TSV) in a Asciidoctor table. We must set the table attribute format to the value tsv. The data can be inside the document, but also defined in an external file which we add with the include macro.

In the following example markup we have a table with inline tab separated values. A second table includes an external file with tab delimited values:

When we write a list in Asciidoctor we can simply create a list item by starting the line with a dot (.). To create a another list item we simply start a new line with a dot (.). But what if we want to add a list item with multiple paragraphs, or text and a source code block element. We can use the list item continuation (+) to indicate to Asciidoctor we want to keep these together for a single list item.

In the following example we have a list in Asciidoctor markup. The second list item has multiple paragraphs , the third item has an extra admonition block and the fourth item contains a source code block:

Writing a parameterized specification in Spock is easy. We need to add the where: block and use data providers to specify different values. For each set of values from the data providers our specifications is run, so we can test for example very effectively multiple input arguments for a method and the expected outcome. A data provider can be anything that implements the Iterable interface. Spock also adds support for a data table. In the data table we define columns for each variable and in the rows values for each variable. Since Spock 1.1 we can reuse the value of the variables inside the data provider or data table. The value of the variable can only be reused in variables that are defined after the variable we want to reuse is defined.

In the following example we have two feature methods, one uses a data provider and one a data table. The variable sentence is defined after the variable search, so we can use the search variable value in the definition of the sentence variable.