I just released the first version of my Taming Thymeleaf book on leanpub. Since I am using Asciidoctor to generate the PDF, there is no automatic table of contents generation for the landing page. Luckily, leanpub allows to enter some HTML to manually create the TOC.
A perfect opportunity to use my rusty Groovy skills once more to generate this HTML.
I have my Asciidoc files all in a _chapters directory grouped per chapter:
chapter-01.adoc
chapter-02.adoc
chapter-03.adoc
chapter-04.adoc
chapter-05.adoc
...Asciidoc uses == and === indicate chapter titles.
This is an example from chapter-01.adoc:
== What are Spring Boot and Thymeleaf?
=== Spring Framework
Spring Boot is based upon the https://projects.spring.io/spring-framework/[Spring Framework], which is at its core
a dependency-injection container. Spring makes it easy to define everything in your application as loosely coupled
components which Spring will tie together at run time. Spring also has a programming model that allows you to make
abstractions from specific deployment environments.This Groovy script loops over all files and searches for the level 1 (==) and level 2 (===) Asciidoc headings:
println('<ul class="toc no-parts">')
int chapterNumber = 1;
def files = new File('_chapters').listFiles(new FilenameFilter() {
@Override
boolean accept(File dir, String name) {
return name.startsWith('chapter-')
}
})
files.sort().each { File file ->
def lines = file.readLines()
println('<li>')
int sectionNumber = 1;
lines.forEach({ it ->
if (it.startsWith("== ")) {
println("<span class=\"section-number\">${chapterNumber++}. </span>${it - "== "}")
println('<ul>')
}
if (it.startsWith("=== ")) {
println("""
<li>
<span class="section-number">${chapterNumber}.${sectionNumber++} </span>${it - "=== "}
</li>
""")
}
}
)
println('</ul>')
println('</li>')
}
println('</ul>')The resulting HTML is something like:
<ul class="toc no-parts">
<li>
<span class="section-number">1. </span>What are Spring Boot and Thymeleaf?
<ul>
<li>
<span class="section-number">2.1 </span>Spring Framework
</li>
<li>
<span class="section-number">2.2 </span>Spring Boot
</li>
<li>
<span class="section-number">2.3 </span>Thymeleaf
</li>
</ul>
</li>
<li>
<span class="section-number">2. </span>Getting started
<ul>
<li>
<span class="section-number">3.1 </span>Prerequisites
</li>
<li>
<span class="section-number">3.2 </span>Spring Initializer
</li>
<li>
<span class="section-number">3.3 </span>Summary
</li>
</ul>
</li>
...
</ul>See https://leanpub.com/taming-thymeleaf for the full generated Table of Contents.