SassFX

SassFX is a pure Java 17 Sass compiler. It compiles SCSS, indented Sass, and plain CSS to standard CSS, validated JavaFX CSS, or JavaFX binary stylesheets (BSS).

SassFX does not invoke Dart Sass or Node.js, use FFI, load JavaFX, or ship native libraries.

Features

• Pure Java compiler and frontends targeting Java 17.
• Standard CSS, JavaFX CSS, and JavaFX BSS output.
• JavaFX 8 through 27 target models and BSS versions 5 through 9.
• Java API with source maps, diagnostics, custom importers, and custom functions.
• Cacheable Gradle plugin for compiling project resources.
• Command-line and Embedded Sass Protocol frontends.

Modules

Module	Purpose
sassfx-core	Compiler and reusable Java API
sassfx-cli	Standalone command-line application
sassfx-embedded	Embedded Sass Protocol endpoint for host tools
sassfx-gradle-plugin	Gradle build integration

The core artifact is a regular library JAR. The CLI, Embedded endpoint, and Gradle plugin are published as self-contained JARs with relocated runtime dependencies.

Gradle Plugin

Apply the plugin and configure the desired output target:

plugins {
    java
    id("org.glavo.sassfx") version "<version>"
}

sassfx {
    target.set("css/javafx@21")
    style.set("compressed")
    loadPaths.from(layout.projectDirectory.dir("src/shared/scss"))
}

By default, compileScss compiles entrypoints under src/main/scss into build/generated/sassfx/main. When the Java plugin is present, the generated files are included in processResources automatically.

The target selector accepts:

Selector	Output
css	Standard CSS
css/javafx@8 through css/javafx@27	Validated JavaFX CSS
bss/javafx@8 through bss/javafx@27	JavaFX BSS

Java API

Add the core library from Maven Central:

dependencies {
    implementation("org.glavo:sassfx-core:<version>")
}

Compile a stylesheet to standard CSS:

import org.glavo.sassfx.CssTarget;
import org.glavo.sassfx.SassCompiler;
import org.glavo.sassfx.SassSource;

import java.nio.file.Files;
import java.nio.file.Path;

var result = new SassCompiler().compile(
        SassSource.fromFile(Path.of("style.scss")),
        CssTarget.DEFAULT
);

Files.writeString(Path.of("style.css"), result.output());

Use JavaFXCssTarget for validated JavaFX CSS and BssTarget for binary stylesheets. CompileOptions configures source maps, load paths, diagnostics, custom importers, and custom Sass functions.

Command Line

Run the self-contained CLI JAR:

java -jar sassfx-cli-<version>.jar style.scss -o style.css

Select a JavaFX target when needed:

java -jar sassfx-cli-<version>.jar \
  --target bss/javafx@27 \
  style.scss \
  -o style.bss

Use --help for the complete option reference:

java -jar sassfx-cli-<version>.jar --help

Embedded Sass

The sassfx-embedded artifact provides a standalone Embedded Sass Protocol endpoint:

java -jar sassfx-embedded-<version>.jar

The CLI artifact exposes the same endpoint through --embedded. This interface is intended for Sass host implementations; ordinary application builds should normally use the Gradle plugin, CLI, or Java API.

Building

Use the checked-in Gradle Wrapper:

./gradlew check

On Windows:

.\gradlew.ps1 check

Product code and artifacts target Java 17. Generating Javadoc requires a JDK 25 toolchain because the sources use Markdown-style /// documentation comments.

Project Documentation

• CHANGELOG.md records user-visible changes and current limitations.
• UPSTREAM.md records pinned Sass compatibility baselines.
• ORACLES.md describes JavaFX runtime verification.
• RELEASING.md describes the release workflow.
• THIRD-PARTY-NOTICES.md contains attribution and compatibility-source notices.

License

SassFX is licensed under the Mozilla Public License 2.0.