Markdown script for usage of PegDown - converts md files into html

markdown.gradle

/*
 * Adapted from https://raw.github.com/geb/geb-seconf-2012-slides/master/buildSrc/pegdown/src/main/groovy/org/gradle/plugins/pegdown/PegDown.groovy
 */
 
buildscript {
  repositories {
    mavenCentral()
  }

  dependencies {
    classpath "org.pegdown:pegdown:1.1.0"
  }
}

class FileConcatTask extends SourceTask {
   @Input @Optional byte[] joiner

   private destination
   @OutputFile File getDestination() { project.file(destination) }
   void setDestination(destination) { this.destination = destination }

   @TaskAction
   void doFileConcat() {
       getDestination().withOutputStream { out ->
           getSource().files.sort { it.name }.each {
               it.withInputStream { out << it }
               if (joiner) {
                   out << joiner
               }
           }
       }
   }
}

task concatMarkdown(type: FileConcatTask) {
   source fileTree("docs") { include "*.md" }
   destination "$buildDir/all.md"
   joiner "\n\n".getBytes("UTF-8")
}

task markdown(type: PegDown) {
   inputEncoding "utf-8"
   outputEncoding "utf-8"
   source concatMarkdown
   destination "$buildDir/html/raw.html"
}

import org.gradle.api.tasks.Input
import org.gradle.api.tasks.Optional
import org.gradle.api.tasks.SourceTask
import org.gradle.api.tasks.OutputFile
import org.gradle.api.tasks.TaskAction
import org.pegdown.Extensions
import org.gradle.api.InvalidUserDataException
import org.pegdown.PegDownProcessor

class PegDown extends SourceTask {

    @Input
    @Optional
    List<String> options

    @Input
    String inputEncoding

    @Input
    String outputEncoding

    private destination
    
    void setDestination(destination) {
        this.destination = destination
    }

    @OutputFile
    def getDestination() {
        return project.file(destination)
    }

    @TaskAction
    void process() {
        int optionsValue = getCalculatedOptions()
        PegDownProcessor processor = new PegDownProcessor(optionsValue)
        String markdown = getSource().singleFile.getText(getInputEncoding())
        String html = processor.markdownToHtml(markdown)
        getDestination().write(html, getOutputEncoding())
    }
    
    int getCalculatedOptions() {
        getOptions().inject(0) { acc, val -> acc | toOptionValue(val) } as int
    }
    
    protected int toOptionValue(String optionName) {
        String upName = val.toUpperCase()
        try {
            Extensions."$upName"
        } catch (MissingPropertyException e) {
            throw new InvalidUserDataException("$optionName is not a valid PegDown extension name")
        }
    }
    
    void options(String... options) {
        this.options.addAll(options)
    }
}