KotlinPoet DSL

Lightweight Kotlin extension of KotlinPoet, providing Kotlin DSL functionality and other convenient solutions.

• Full of convenient methods to achieve minimum code writing possible.
• Options to invoke DSL. For example, method("main") { ... } is as good as methods { "main" { ... } }. Scroll down for more information.
• Smooth transition, existing KotlinPoet native specs can still be configured with DSL.

buildFileSpec("com.example.helloworld", "HelloWorld") {
    classType("HelloWorld") {
        modifiers(PUBLIC, FINAL)
        methods {
            "main" {
                modifiers(PUBLIC, STATIC)
                returns = UNIT
                parameter("args", STRING.array)
                appendLine("%T.out.println(%S)", System::class, "Hello, KotlinPoet!")
            }
        }
    }
}.writeTo(System.out)

Download

repositories {
    mavenCentral()
}
dependencies {
    implementation "com.hendraanggrian:kotlinpoet-dsl:$version"
}

Usage

Use T::class as parameters

KClass<*> can now be used as format arguments. There is also inline reified type function whenever possible.

buildMethodSpec("sortList") {
    returns = int
    parameters.add(classNamed("java.util", "List").parameterizedBy(hoverboard), "list")
    appendLine("%T.sort(list)", Collections::class)
    appendLine("return list")
}

buildFieldSpec("count", INT) {
    initializer("%L", 0)
}

Optional DSL

Some elements (field, method, parameter, etc.) are wrapped in container class. These containers have ability to add components with/without invoking DSL.

For example, 2 examples below will produce the same result.

types.addClass("Car") {
    methods {
        "getWheels" {
            returns = INT
            appendLine("return wheels")
        }
        "setWheels" {
            parameter("wheels", INT)
            appendLine("this.wheels = wheels")
        }
    }
}

types.addClass("Car") {
    method("getWheels") {
        returns = INT
        appendLine("return wheels")
    }
    method("setWheels") {
        paraneter("wheels", INT)
        appendLine("this.wheels = wheels")
    }
}

Property delegation

In spirit of Gradle Kotlin DSL, creating a spec can be done by delegating to a property.

val title by parametering(String::class) {
    annotation<NotNull>
}

val message by parametering(String::class) {
    annotation<Nullable>
}

Fluent TypeName API

Write TypeName and all its subtypes fluently.

val myClass: ClassName =
    classNamed("com.example", "MyClass")

val listener: LambdaTypeName =
    STRING.lambdaBy(returns = UNIT)

val memberOfString: MemberTypeName =
    myClass.memberOf("myField")

val pairOfInteger: ParameterizedTypeName =
    Pair::class.name.parameterizedBy(Int::class, Int::class)

val tVariable: TypeVariableName =
    "T".generics

val producerOfCharSequence: WildcardTypeName =
    CharSequence::class.name.producerOf()