How do I configure asciidoctor-gradle-plugin to handle plantuml?

Question

I don't know any Ruby but I do like asciidoctor (and the gradle plugin). Is there a simple way to get the plugin to generate plantuml diagrams?

I looked at the basic asciidoctor-diagrams functionality which seems specific to using the native/ruby asciidoctor extension (which I don't have and would rather not install since I like using the gradle plugin).

The nicely done asciidoctor-gradle-plugin documentation page shows that it accepts a requires option for Ruby modules but having no grounding in Ruby whatsoever, I'm not sure if that's what I need or not.

I tried the path of least resistant, i.e.:

asciidoctor {
    logDocuments = true
    separateOutputDirs = false
    sourceDir = file("src")
    outputDir = file("$buildDir/html")
    backends = [ 'html5' ]
    requires "asciidoctor-diagram"
}

Against my basic plantuml test:

.The PlantUML block extension class
[plantuml, sample-plantuml-diagram, alt="Class diagram", width=135, height=118]
----
class BlockProcessor
class PlantUmlBlock
BlockProcessor <|-- PlantUmlBlock
----

But got:

* What went wrong:
Execution failed for task ':asciidoctor'.
> (LoadError) no such file to load -- asciidoctor-diagram

during the configuration phase.

How can I configure asciidoctor-gradle-plugin to handle plantuml?

Answer 1

mrhaki to the rescue. I don't want to totally rip-off his post, but in case that link ever goes bad, there are numerous other dependencies that need to be met in the gradle file the first that I didn't have was com.github.jruby-gradle:jruby-gradle-plugin:0.1.5 then he applies two plugins including com.github.jruby-gradle.base and has a dependency on ruby gems (rubygems:asciidoctor-diagram:1.2.0). I think his blog site is pretty reliable so I won't go into the details.