Forge is a JSON parsing library that helps you map your Kotlin class from a JSON in a functional way. Forge is highly inspired by Aeson, JSON parsing library in Haskell.
repositories {
jcenter()
}
dependencies {
compile 'com.github.kittinunf.forge:forge:<latest-version>'
}
Given you have JSON as such
{
"id": 1,
"name": "Clementina DuBuque",
"age": 46,
"email": "Rey.Padberg@karina.biz",
"friends": [
{
"id": 11,
"name": "Ervin Howell",
"age": 32,
"email": "Shanna@melissa.tv",
"friends": []
}
],
"dogs": [
{
"name": "Lucy",
"breed": "Dachshund",
"is_male": false
}
]
}You can write your Kotlin class definition as such
data class User(val id: Int,
val name: String,
val age: Int,
val email: String?,
val friends: List<User>,
val dogs: List<Dog>?)
data class Dog(val name: String, val breed: String, val male: Boolean)
fun userDeserializer(json: JSON) =
::User.create.
map(json at "id").
apply(json at "name").
apply(json at "age").
apply(json maybeAt "email").
apply(json.list("friends", ::userDeserializer)). //userDeserializer is a function, use :: as a function reference
apply(json.maybeList("dogs", dogDeserializer)) //dogDeserializer is a lambda, use it directly
val dogDeserializer = { json: JSON ->
::Dog.create.
map(json at "name").
apply(json at "breed").
apply(json at "is_male")
}
Viola!, then, you can deserialize your JSON like
//jsonContent is when you receive data as a JSON
val result = Forge.modelFromJson(jsonContent, ::userDeserializer)
when (result) {
DeserializedResult.Success -> {
val user = result.value
//success, do something with user
}
DeserializedResult.Failure -> {
val error = result.error
//failure, do something with error
}
}