Chart Java API

Relevant source files

• charts/pom.xml

The Chart Java API (patternfly-java-charts module) provides Java component wrappers for PatternFly chart visualizations. This module packages chart components as a GWT library (gwt-lib) that integrates with both GWT and J2CL applications. The Java API serves as a type-safe interface to chart web components that are implemented using React and distributed via the @patternfly-java/charts NPM package.

For information about the underlying web component implementation, see Chart Web Components. For details on the NPM package build process, see Chart Build and Publishing.

Module Overview

The patternfly-java-charts module follows the standard PatternFly Java architecture but uses specialized packaging to support chart-specific requirements. The module provides Java component classes that extend BaseComponent and integrate with the chart web components at runtime.

Sources: charts/pom.xml1-77

GWT Library Packaging

The charts module uses the gwt-lib packaging type, which differs from standard JAR packaging in several important ways:

Aspect	Configuration	Purpose
Packaging Type	gwt-lib	Produces a GWT library archive suitable for both GWT and J2CL consumption
Module Name	org.patternfly.Charts	Defines the GWT module descriptor location
Resource Inclusion	.js files from src/main/java and src/main/resources	Includes JavaScript resources needed by chart components

The gwt-lib packaging is configured via the gwt-maven-plugin:

charts/pom.xml68-74

This packaging type ensures that:

1. Java source files are included in the artifact for compilation
2. GWT module descriptors (.gwt.xml files) are preserved
3. JavaScript resources are bundled with the library
4. The artifact can be consumed by both GWT and J2CL projects

Sources: charts/pom.xml31 charts/pom.xml68-74

Module Dependencies

The charts module depends on two core PatternFly Java modules:

Core Dependencies

1. patternfly-java-core - Provides foundational classes:

   • BaseComponent for HTML element wrapping
   • Elemento builder API integration
   • Component lifecycle management
   • Event handling infrastructure

2. patternfly-java-tokens - Provides design system integration:

   • Token enum with CSS custom properties
   • Design token constants for styling
   • Access to PatternFly theme variables

charts/pom.xml35-43

Sources: charts/pom.xml35-43

JavaScript Resource Handling

The charts module includes JavaScript files as resources, which are packaged with the GWT library for runtime access. This configuration allows chart components to load necessary JavaScript code when integrated into applications.

The resource configuration includes two directories:

charts/pom.xml52-64

This dual-directory approach allows:

• Co-location of JavaScript code with Java components (src/main/java)
• Separation of pure JavaScript resources (src/main/resources)
• Flexible resource organization while maintaining GWT compatibility

Sources: charts/pom.xml52-64

GWT Module Descriptor

The module defines a GWT module descriptor named org.patternfly.Charts, which serves as the entry point for integrating chart components into GWT applications. Applications using charts must inherit this module in their own .gwt.xml file:

The module descriptor:

1. Declares dependencies on patternfly-java-core and patternfly-java-tokens modules
2. Specifies source paths for Java-to-JavaScript compilation
3. Configures resource loading for JavaScript files
4. Ensures proper inheritance chain for GWT compilation

charts/pom.xml72

Sources: charts/pom.xml72

Chart Component Architecture

Chart components in the Java API follow the standard PatternFly Java component pattern, extending BaseComponent and implementing chart-specific interfaces. The architecture bridges Java code with React-based web components:

The Java components:

1. Provide type-safe configuration methods for chart properties
2. Generate custom element tags recognized by the web component layer
3. Set attributes that are parsed by the React wrapper
4. Integrate with PatternFly design tokens for theming

Sources: charts/pom.xml36-39

Integration with Applications

Applications using the charts module must:

1. Add the Maven dependency:

2. For GWT applications: Inherit the Charts module in .gwt.xml:

3. For J2CL applications: Include the charts module in the classpath; the patternfly-java-j2cl module handles integration automatically.

4. Include runtime dependencies: The @patternfly-java/charts NPM package must be available at runtime, as documented in Chart Web Components.

Sources: charts/pom.xml1-77

Testing Configuration

The charts module includes JUnit Jupiter for unit testing, following the standard PatternFly Java testing approach:

charts/pom.xml45-48

Tests verify:

• Component initialization and configuration
• Attribute serialization for web component integration
• Design token application
• Element hierarchy construction

Sources: charts/pom.xml45-48