https://github.com/vuzi/play-json-auto-sealed-trait
Auto generation of writer/reader/format for sealed trait, using play-json
https://github.com/vuzi/play-json-auto-sealed-trait
json-format play-json scala scala-macros
Last synced: about 1 month ago
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Auto generation of writer/reader/format for sealed trait, using play-json
- Host: GitHub
- URL: https://github.com/vuzi/play-json-auto-sealed-trait
- Owner: Vuzi
- License: apache-2.0
- Created: 2018-01-25T14:29:23.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2018-02-20T16:30:00.000Z (about 7 years ago)
- Last Synced: 2025-01-25T23:38:50.751Z (3 months ago)
- Topics: json-format, play-json, scala, scala-macros
- Language: Scala
- Size: 17.6 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Auto format for sealed trait using `play-json`
## Features
- Automatic generation of reader/writer for sealed trait
- Handle case class, case object, objects, nested case class/object and sub type extending the sealed trait
- Customisable JSON type field
## Description
Auto generation of writer/reader/format for sealed trait, using `play-json`. The key difference with `play-json` sealed trait macro is that here the readers/writers of every class or object implementing the sealed trait is automatically generated using the `play-json` existing macros. This allow for quick `format` generation where the default format would have been used.
## Example/Usage
```scala
sealed trait Test
case class TestA(value: Int) extends Test
case class TestB(value: String) extends Test
object TestC extends Test
sealed trait Test2 extends Test
case class Test2A(a: Int) extends Test2
sealed trait Test3 extends Test2
case class Test3A(a: String) extends Test3
object Test {
case class TestD(value: String) extends Test
object TestE extends Test
case object TestF extends Test
object InnerTest {
case object TestInner extends Test
}
implicit val writer: Format[Test] = format[Test]
}
object MacroTest extends App {
val testA = TestA(42)
val testB = TestB("hello")
val testC = TestC
val testD = TestD("hey")
val testE = TestE
val testF = TestF
val testI = TestInner
val test2A = Test2A(42)
val test3A = Test3A("42")
assert(Json.fromJson[Test](Json.toJson(testA)) == JsSuccess(testA))
assert(Json.fromJson[Test](Json.toJson(testB)) == JsSuccess(testB))
assert(Json.fromJson[Test](Json.toJson(testC)) == JsSuccess(testC))
assert(Json.fromJson[Test](Json.toJson(testD)) == JsSuccess(testD))
assert(Json.fromJson[Test](Json.toJson(testE)) == JsSuccess(testE))
assert(Json.fromJson[Test](Json.toJson(testF)) == JsSuccess(testF))
assert(Json.fromJson[Test](Json.toJson(testI)) == JsSuccess(testI))
assert(Json.fromJson[Test](Json.toJson(test2A)) == JsSuccess(test2A))
assert(Json.fromJson[Test](Json.toJson(test3A)) == JsSuccess(test3A))
}
```
Heavily inspired by [`play-json`](https://github.com/playframework/play-json) own macros!