Config4k

Config for Kotlin.

Config4k is a lightweight Typesafe Config wrapper for Kotlin and inspired by ficus, providing simple extension functions

Config.extract

Any.toConfig

Config

Table of Contents

• Installation
• Usage
  • Delegated Properties
  • Deserialization
  • Data Classes
  • Nullable
  • Enum
  • Serialization
  • String
  • ConfigRenderOptions
• Supported types
• Contribute ## Installation

Gradle:

repositories {
    mavenCentral()
}


dependencies {
    compile 'io.github.config4k:config4k:xxx' // See the Download badge
}

Usage

Delegated Properties

By far the simplest way to use config4k is via Kotlin Delegated Properties:

val config = ConfigFactory.parseString("""
                                          |stringValue = hello
                                          |booleanValue = true
                                          |""".trimMargin())

val stringValue: String by config
println(stringValue) // hello
val nullableStringValue: String? by config
println(nullableStringValue) // null
val booleanValue: Boolean by config
println(booleanValue) // true

Deserialization

Config.extract

Config

T

Map

Maps can be serialized with

String

kotlin
val config = ConfigFactory.parseString("""
                                          |map {  
                                          |  foo = 5
                                          |  bar = 6
                                          |}""".trimMargin())
val map: Map = config.extract

kotlin
val config = ConfigFactory.parseString("""
                                          |map = [{  
                                          |  key = 5
                                          |  value = "foo"
                                          |}
                                          |{
                                          |  key = 6
                                          |  value = "bar"
                                          |}]""".trimMargin())
val map: Map = config.extract

Data Classes

Config4k has no option to use different names between code and config file. ```kotlin data class Person(val name: String, val age: Int)

val config = ConfigFactory.parseString(""" |key {
| name = "foo" | age = 20 |}""".trimMargin()) val person: Person = config.extract("key") println(person.name == "foo") // true println(person.age == 20) // true ``` For more details, please see TestArbitraryType.kt

Nullable

Using

extract

Config.hasPath()

extract

T

null

kotlin
val config = ConfigFactory.parseString("""key = 10""")
val key = config.extract("key")
val foo = config.extract("foo")
println(key == 10) // true
println(foo == null) // true

Enum

Config4k also supports Enum. Enum is converted to String of its name in the config file. ```kotlin enum class Size { SMALL, MEDIUM, LARGE }

val config = ConfigFactory.parseString("""key = SMALL""") val small = config.extract("key") println(small == Size.SMALL) // true ``` Test Class: TestEnum.kt

Serialization

Any.toConfig

Config

String

You can use ConfigValue.render() to serialize

Config

Config

kotlin
data class Person(val name: String, val age: Int)
val person = Person("foo", 20).toConfig("person")
println(person.root().render())

{
    # hardcoded value
    "person" : {
        # hardcoded value
        "age" : 20,
        # hardcoded value
        "name" : "foo"
    }
}

ConfigRenderOptions

Typesafe Config's class

ConfigRenderOptions

ConfigValue.render

kotlin
// If setJson(false) is called, ConfigValue.render returns HOCON
data class Person(val name: String, val age: Int)
val person = Person("foo", 20).toConfig("person")
val options = ConfigRenderOptions.defaults().setJson(false)
println(person.root().render(options))

    # hardcoded value
person {
    # hardcoded value
    age=20
    # hardcoded value
    name=foo
}

// setOriginComments(false) removes comments
data class Person(val name: String, val age: Int)
val person = Person("foo", 20).toConfig("person")
val options = ConfigRenderOptions.defaults()
                        .setJson(false)
                        .setOriginComments(false)
println(person.root().render(options))

Output:

person {
    age=20
    name=foo
}

Supported types

Property delegation,

extract

toConfig

Boolean

Byte

Int

Long

Float

Double

String

import java.io.File

import java.nio.file.Path

java.time.Duration

java.time.Period

java.time.temporal.TemporalAmount

kotlin.text.Regex

List

Set

Map

Array

Array

Array>

T?

toConfig

com.typesafe.config.Config

com.typesafe.config.ConfigValue

com.typesafe.config.ConfigMemorySize

See SelectReader.kt for the exhaustive list.

Snapshots

All snapshot artifacts are available in the Sonatype snapshots repository.

Contribute

Would you like to contribute to Config4k?
Take a look at CONTRIBUTING.md