BuildConfig Gradle Plugin

BuildConfig Gradle Plugin is a Gradle plugin for generating static fields from Gradle buildscript.

In Android, there is a feature called BuildConfig. Android Gradle Plugin generates BuildConfig class on build time that contains some static fields likes application id, version name and user defined values. It is very helpful for using build-related data in android source code. But, there is no feature in normal JVM project. This project's main goal is offering BuildConfig-like features in JVM gradle project.

Getting Started

Setup

This plugin requires JDK 8 or above.

BuildConfig Gradle Plugin is published on Maven Central. To use this plugin, set mavenCentral repository in pluginManagement or buildscript block.

Using pluginManagement block:

pluginManagement {
    repositories {
        mavenCentral()
    }
}

Using buildscript block:

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath "io.woong.buildconfig:buildconfig-gradle-plugin:x.y.z"
    }
}

Applying plugin

Apply plugin to where you want to configure build config. This plugin depends on java or kotlin-jvm plugin. Before applying this plugin, set java, java-library or org.jetbrains.kotlin.jvm plugin.

Using plugin DSL:

plugins {
    java
    id "io.woong.buildconfig" version "x.y.z"
}

Using apply method:

apply plugin: "java"
apply plugin: "io.woong.buildconfig"

Setting Static Fields

BuildConfig Gradle Plugin provides an extension named buildConfig. In buildConfig scope, you can define static fields and class configurations.

buildConfig {
    field("APP_NAME", "SampleApp")                    // String field.
    field("VERSION_CODE", 12)                         // Int field.
    field("VERSION_NAME", "1.5.0")                    // String field.
    field("API_KEY", System.getenv("SAMPLE_API_KEY")) // String field from system env variable.
}

Generating Static Fields

It offers a gradle task, genBuildConfig. Run this task to generate static class.

./gradlew genBuildConfig

After executing gradle task, You can access generated class in source code like below:

public class BuildConfigSample {
    public static void main(String[] args) {
        String appName = BuildConfig.APP_NAME;
        int versionCode = BuildConfig.VERSION_CODE;
        String versionName = BuildConfig.VERSION_NAME;
        String apiKey = BuildConfig.API_KEY;
    }
}

Configuration

Supported Types

This plugin only supports primitives and string type.

buildConfig {
    field("BYTE_FIELD", (byte) 12)
    field("SHORT_FIELD", (short) 400)
    field("INT_FIELD", 20000)
    field("LONG_FIELD", (long) 21000000000L)
    field("FLOAT_FIELD", 1601.5f)
    field("DOUBLE_FIELD", 12131.0)
    field("CHAR_FIELD", 'c')
    field("STRING_FIELD", "this is string sample")
}

Customizing Package and Class Name

If you want to create static fields in custom package or class, set packageName and className property in buildConfig block.

For instance, if you set build config like below:

buildConfig {
    packageName = "com.example.app.build" // Set custom package name.
    className = "BuildMetadata"           // Set custom class name.
    field("APP_NAME", "SampleApp")
    field("VERSION_CODE", 12)
    field("VERSION_NAME", "1.5.0")
    field("API_KEY", System.getenv("SAMPLE_API_KEY"))
}

The BuildMetadata class will be generated in com.example.app.build package.

package com.example.app;

import com.example.app.build.BuildMetadata;

public class BuildConfigSample {
    public static void main(String[] args) {
        String appName = BuildMetadata.APP_NAME;
        int versionCode = BuildMetadata.VERSION_CODE;
        String versionName = BuildMetadata.VERSION_NAME;
        String apiKey = BuildMetadata.API_KEY;
    }
}

License

This project is licensed under the Apache License, Version 2.0. See license file for more detail.

cheonjaeung/buildconfig-gradle-plugin