dector / gradle-buildconfig-plugin

A plugin for generating BuildConstants for any kind of Gradle projects: Java, Kotlin, Groovy, etc. Designed for KTS scripts.

gradle-buildconfig-plugin

A plugin for generating BuildConstants for any kind of Gradle projects: Java, Kotlin, Groovy, etc. Designed for KTS scripts, with experimental support for Kotlin's multi-platform plugin

Usage in KTS

On your build.gradle.kts add:

plugins {
    id("org.jetbrains.kotlin.jvm") version embeddedKotlinVersion
    id("com.github.gmazzo.buildconfig") version <current version>
}

buildConfig {
    buildConfigField("String", "APP_NAME", "\"${project.name}\"")
    buildConfigField("String", "APP_VERSION", provider { "\"${project.version}\"" })
    buildConfigField("String", "APP_SECRET", "\"Z3JhZGxlLWphdmEtYnVpbGRjb25maWctcGx1Z2lu\"")
    buildConfigField("long", "BUILD_TIME", "${System.currentTimeMillis()}L")
    buildConfigField("boolean", "FEATURE_ENABLED", "${true}")
    buildConfigField("IntArray", "MAGIC_NUMBERS", "intArrayOf(1, 2, 3, 4)")
    buildConfigField("com.github.gmazzo.SomeData", "MY_DATA", "new SomeData(\"a\",1)")
}

Will generate BuildConfig.kt:

object BuildConfig {
    const val APP_NAME: String = "example-kts"

    const val APP_VERSION: String = "0.0.1"

    const val APP_SECRET: String = "Z3JhZGxlLWphdmEtYnVpbGRjb25maWctcGx1Z2lu"

    const val BUILD_TIME: Long = 1551108377126L

    const val FEATURE_ENABLED: Boolean = true

    val MAGIC_NUMBERS: IntArray = intArrayOf(1, 2, 3, 4)

    val MY_DATA: SomeData = SomeData("a",1)

    val RESOURCE_CONFIG_LOCAL_PROPERTIES: File = File("config/local.properties")

    val RESOURCE_CONFIG_PROD_PROPERTIES: File = File("config/prod.properties")

    val RESOURCE_FILE2_JSON: File = File("file2.json")

    val RESOURCE_FILE1_JSON: File = File("file1.json")
}

Usage in Groovy

On your build.gradle add:

plugins {
    id 'java'
    id 'com.github.gmazzo.buildconfig' version <current version>
}

buildConfig {
    buildConfigField('String', 'APP_NAME', "\"${project.name}\"")
    buildConfigField('String', 'APP_VERSION', provider { "\"${project.version}\"" })
    buildConfigField('String', 'APP_SECRET', "\"Z3JhZGxlLWphdmEtYnVpbGRjb25maWctcGx1Z2lu\"")
    buildConfigField('long', 'BUILD_TIME', "${System.currentTimeMillis()}L")
    buildConfigField('boolean', 'FEATURE_ENABLED', "${true}")
    buildConfigField('int[]', 'MAGIC_NUMBERS', '{1, 2, 3, 4}')
    buildConfigField("com.github.gmazzo.SomeData", "MY_DATA", "new SomeData(\"a\",1)")
}

Will generate BuildConfig.java:

public final class BuildConfig {
    public static final String APP_NAME = "example-groovy";

    public static final String APP_VERSION = "0.0.1";

    public static final String APP_SECRET = "Z3JhZGxlLWphdmEtYnVpbGRjb25maWctcGx1Z2lu";

    public static final long BUILD_TIME = 1550999393550L;

    public static final boolean FEATURE_ENABLED = true;

    public static final int[] MAGIC_NUMBERS = {1, 2, 3, 4};

    public static final SomeData MY_DATA = new SomeData("a", 1);

  private BuildConfig() {
  }
}

Customizing the class

If you add in your build.gradle.kts:

buildConfig {
    className("MyConfig")   // forces the class name. Defaults to 'BuildConfig'
    packageName("com.foo")  // forces the package. Defaults to '${project.group}'

    useJavaOutput()                                 // forces the outputType to 'java'
    useKotlinOutput()                               // forces the outputType to 'kotlin', generating an `object`
    useKotlinOutput { topLevelConstants = true }    // forces the outputType to 'kotlin', generating top-level declarations
    useKotlinOutput { internalVisibility = true }   // adds `internal` modifier to all declarations
}

Will generate com.foo.MyConfig in a MyConfig.java file.

Secondary classes

Sometimes one generated does not fits your needs or code style. You may add multiple classes with the following syntax:

buildConfig {
    buildConfigField("String", "FIELD1", "\"field1\"")

    forClass("OtherClass") {
        buildConfigField("String", "FIELD2", "\"field2\"")
    }

    forClass(packageName = "", className = "RootConfig") {
        buildConfigField("String", "FIELD3", "\"field3\"")
    }
}

Will generate the files:

• com.github.gmazzo.BuildConfig
• com.github.gmazzo.OtherClass
• RootConfig (in the root package)

Generate top-level constants

On your build.gradle.kts add:

buildConfig {
    useKotlinOutput { topLevelConstants = true }

    buildConfigField("String", "APP_NAME", "\"${project.name}\"")
    buildConfigField("String", "APP_VERSION", "\"0.0.1\"")
}

Will generate BuildConfig.kt:

const val APP_NAME: String = "example-kts"

const val APP_VERSION: String = "0.0.1"
}

Values greater than 100 characters

In some cases, such as embedded public certs, your build config values may exceed 100 characters in length and will become subject to line wrapping by the Kotlin Poet output. If you need to workaround this behavior, you can explicitly control or prevent line wrapping by replacing spaces with a · character.

val alphabet = (65..90)
    .map { it.toChar() }
    .joinToString(separator = ",·")

buildConfigField("String", "Example", "\"$alphabet\"")

will generate BuildConfig.kt:

object BuildConfig {
    const val Example: String =
            "A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z"
}

Advanced

Generate constants for 'test' sourceSet (or any)

If you add in your build.gradle.kts:

buildConfig {
    sourceSets.getByName("test") {
        buildConfig {
            buildConfigField("String", "TEST_CONSTANT", "\"aTestValue\"")
        }
    }
}

Will generate in TestBuildConfig.kt:

object TestBuildConfig {
    const val TEST_CONSTANT: String = "aTestValue"
}

Or in Groovy:

sourceSets {
    test {
        buildConfig {
            buildConfigField('String', 'TEST_CONSTANT', '"aTestValue"')
        }
    }
}

Generate constants from resources files

Assuming you have the following structure:

myproject
- src
  - main
    - resources
      - config
        - local.properties
        - prod.properties
      - file1.json
      - file1.json

If you add in your build.gradle.kts:

val generateBuildConfig by tasks

task("generateResourcesConstants") {
    val buildResources = buildConfig.forClass("BuildResources")

    doFirst {
        sourceSets["main"].resources.asFileTree.visit(Action<FileVisitDetails> {
            val name = path.toUpperCase().replace("\\W".toRegex(), "_")

            buildResources.buildConfigField("java.io.File", name, "File(\"$path\")")
        })
    }

    generateBuildConfig.dependsOn(this)
}

Will generate in BuildResources.kt:

object BuildResources {
    val CONFIG_LOCAL_PROPERTIES: File = File("config/local.properties")

    val CONFIG_PROD_PROPERTIES: File = File("config/prod.properties")

    val FILE1_JSON: File = File("file1.json")

    val FILE2_JSON: File = File("file2.json")
}

Or in Groovy:

task("generateResourcesConstants") {
    def buildResources = buildConfig.forClass("BuildResources")

    doFirst {
        sourceSets["main"].resources.asFileTree.visit { file ->
            def name = file.path.toUpperCase().replaceAll("\\W", "_")

            buildResources.buildConfigField("java.io.File", name, "new File(\"$file.path\")")
        }
    }

    generateBuildConfig.dependsOn(it)
}

Will generate in BuildResources.java:

  public static final File CONFIG_LOCAL_PROPERTIES = new File("config/local.properties");

  public static final File CONFIG_PROD_PROPERTIES = new File("config/prod.properties");

  public static final File FILE2_JSON = new File("file2.json");

  public static final File FILE1_JSON = new File("file1.json");