Docgen

About

Apache FreeMarker Docgen is an internal project under the Apache FreeMarker TLP, used for generating the FreeMarker Manual, the FreeMarker homepage, and maybe some more.

Docgen generates static web pages from a DocBook 5 “book” XML. But, it only implements the small subset of DocBook elements that we actually use, and it has no backward compatibility guarantees.

Usage

For some examples see:

• The freemarker-site project
• FreeMarker Manual source code
• legacy-tests in this project

For editing DocBook, we are using XXE, with the xxe-addon installed, which you can find in this project.

Building

These tools must be installed:

• JDK 8 (or later), was tested with Oracle 17.0.9
• Apache Maven, was tested with 3.8.1
• Node.js was tested with 22.15.0. (Node.js is only used to generate static content while building Docgen itself.)

To build, ensure that npm and bpx (from Node.js) are in the path, then in the top project directory (freemarker-docgen) issue this:

mvn install

Node.js troubleshooting

Possible node.js related problems and solutions:

• “Error: ENOENT, stat “: create that directory manually, then retry.
• If the system doesn’t find npm: Open a new terminal (command window) so that it picks up the PATH environment variable changes. Adjust it if necessary.
• If the build has once worked, but now keeps failing due to some missing modules, or anything strange, delete the “node_modules” directory, and issue npm install to recreate it.

Running Docgen from your IDE

If you develop/debug Docgen, it’s convenient to launch it from your IDE. As an example, let’s generate the FreeMarker Manual. For that, create a Run Configuration in you IDE, with main class org.freemarker.docgen.cli.Main, and these command line arguments (replace <FREEMARKER_PROJECT_DIR> with the actual directory):

<FREEMARKER_PROJECT_DIR>\src\manual
<FREEMARKER_PROJECT_DIR>\build\manual
offline=true

To ease comparing the outputs of different runs, you can set a fixed value for the last modification with a java argument like this:

-Ddocgen.generationTime=2020-07-15T17:00Z

Compiling LESS and JS

This happens automatically during build, in the generate-resources Maven phase. The generated output is in target\resources-gulp, which will be included in the core jar artifact.

Pagefind (search) support

Can be enabled in the docgen.cjson (a file that’s normally next to the DocBook XML) via pagefindBasedSearch: true.

Pagefind indexing is done when generating the docgen output from the DocBook XML. The output is fully static HTML, with purely cline-side JavaScript that generates the search results. However, due to browser security restrictions, the search functionality will only work if you visit via HTTP(S), and not via a file: URL. For local testing you can use npx http-server for example.

When pagefindBasedSearch is true, Node.js has to be available where Docgen generates its output (the HTML-s), and not just when building Docgen itself! That’s because Pagefind indexing depends on Node.js.

Releasing a new Docgen version

[TODO] Standard ASF release procedure (staging, voting, etc.), so that we can release to the Maven Central. Not advertised, no announcements, no backward compatibility promises, but makes building our dependent projects easier.

Icon Font Attribution

The icon font in this project was built using IcoMoon and contains selected icons from:

• Entypo by Daniel Bruce
• Font Awesome by Dave Gandy.
• Material Design Icons by Google