Kotlin nature extension for SAP Commerce Cloud (Hybris)

Vote for feature - https://influence.sap.com/sap/ino/#/idea/320948

Purpose

Thanks to advanced pluggability of the SAP Commerce, it is possible to enable an alternative language which can be run on JVM.

The same way SAP Commerce enables Groovy code compilation via groovynature extension, this extension adds support of Kotlin language compilation.

Kotlin is a programming language that makes coding concise, cross-platform, and fun

Ultimately, the goal of this extension is to make SAP Commerce developers life easier and fun with Kotlin.

Overview

Kotlin source files have to be placed in kotlinsrc and test source in kotlintestsrc.

It is possible to change version of Kotlin compiler via local.properties without modifying the source of the kotlinnature extension. Kotlin compiler will be automatically downloaded from the JetBrains GitHub, if kotlin-ant.jar is not present in the kotlinnature/lib directory.

Available targets

kotlinnature_compile_mode

This build target provides possibility to adjust how kotlinnature compilation will be done and injected into the Platform.

Mode	Description
compiler_adapter	This mode will be set if current mode is <blank>. This mode changes YJavaC to javac and adds Kotline Compiler Adapter. In this mode Kotlin classes will have visibility to Java classes and vice-versa
after_ext_compile	Alternative compilation mode, similar to OOTB Groovy compilation. It will compile Kotlin classes after compilation of the Java classes. In this mode only Kotlin classes will have visibility to Java classes
uninstall	Special mode, which will undo any modifications to OOTB files (compiling.xml, antmacros.xml, util.xml)
<blank>	No value, initial state. Indicates that there are no changes to OOTB files.

Available macrodefs

Note: below macros will be invoked automatically (no need to make it manually)

Macro	Description
kotlinnature_before_build	macro which will download Kotlin compiler dependencies if kotlinnature/lib/kotlin-ant.jar is missing
kotlin_compile	macro for compiling Kotlin source files
kotlinnature_compile_core	invokes kotlin_compile on core source files
kotlinnature_compile_web	invokes kotlin_compile on web source files
_before_build	initialize kotlinnature extension by invoking kotlinnature_compile_mode to register of the Kotlin compilation

Available properties

Property	Default	Description
kotlinnature.compiler.version	1.9.10	must point to valid Kotlin compiler release version - releases can be found here https://github.com/JetBrains/kotlin/releases
kotlinc.fork	false	if set to true will Fork new process for Kotlin compilation
<ext>.kotlinc.fork		enables extension specific kotlin.fork property
kotlinnature.compiler.mode	<blank>	internal compilation mode flag, indicates how exactly Kotlin classes will be compiled

How-to use

• Checkout this repository and integrate into your project, preferably as a GIT submodule
• Add new kotlinnature extension dependency in localextensions.xml file
• Adjust project's .gitignore file to ignore kotlinnature completely
• Ensure that you're using latest version of the SAP Commerce Developers Toolset plugin for Intellij IDEA, as it will automatically register both kotlinsrc and kotlintestsrc as source directories

Tips & tricks

The below tricks are not needed if compiling.xml was adjusted via invocation of kotlinnature_extension_compile_register build target

• To be able to compile Kotlin source code of the individual extension by calling ant build from its directory, custom macrodef has to be registered

<macrodef name="<extname>_after_build">
    <sequential>
        <build_kotlinnature extname="<extname>"/>
    </sequential>
</macrodef>

• Alternatively, if modification of extension's buildcallback.xml file is not an option and Kotlin source code compilation per individual extension is still a case, one may adjust OOTB's compiling.xml file manually or via provided macro kotlinnature_extension_compile:

<macrodef name="extension_compile">
    <attribute name="extname"/>
    <sequential>
        <extension_compile_core extname="@{extname}"/>
        <kotlinnature_compile_core extname="@{extname}"/>
        <extension_generate_deployment extname="@{extname}"/>
        <extension_compile_web extname="@{extname}"/>
        <kotlinnature_compile_web extname="@{extname}"/>
        <extension_compile_hmc extname="@{extname}"/>
        <extension_compile_backoffice extname="@{extname}"/>
        <extension_compile_hac extname="@{extname}"/>
    </sequential>
</macrodef>