Krate ft. Moshi (Kotlin Budapest Meetup 2021 June)

Krate is a SharedPreferences wrapper library based on Kotlin's delegates. This talk takes you on a journey where you'll learn how the new Moshi-based addon for the library was implemented. We'll touch on type erasure and reflection, testing, debugging, and various advanced Kotlin features along the way.

Resources & more info: https://zsmb.co/talks/krate-ft-moshi/

Transcript

1. zsmb.co zsmb13 A Kotlin library design case study ft Krate Moshi Márton Braun
2. Krate AutSoft/Krate Moshi square/moshi
3. Krate AutSoft/Krate
4. Krate interface Krate { val sharedPreferences: SharedPreferences }
5. Krate interface Krate { val sharedPreferences: SharedPreferences } abstract class SimpleKrate(context: Context) : Krate { override val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context) }
6. interface Krate { val sharedPreferences: SharedPreferences } Krate class MyKrate(context: Context) : SimpleKrate(context) { var onboarded by booleanPref("onboarded") var appOpenCount by intPref("appOpenCount") var username by stringPref("username") } abstract class SimpleKrate(context: Context) : Krate { override val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context) }
7. interface Krate { val sharedPreferences: SharedPreferences } Krate myKrate.onboarded = true myKrate.appOpenCount++ myKrate.username = "t1gg3r" class MyKrate(context: Context) : SimpleKrate(context) { var onboarded by booleanPref("onboarded") var appOpenCount by intPref("appOpenCount") var username by stringPref("username") } abstract class SimpleKrate(context: Context) : Krate { override val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context) }
8. Krate myKrate.onboarded = true myKrate.appOpenCount++ myKrate.username = "t1gg3r" var onboarded by booleanPref("onboarded") var username by stringPref("username") abstract class SimpleKrate(context: Context) : Krate { override val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context) } } var appOpenCount by intPref("appOpenCount") class MyKrate(context: Context) : SimpleKrate(context) {
9. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by intPref("appOpenCount") }
10. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by IntDelegate("appOpenCount") }
11. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by IntDelegate("appOpenCount") } class IntDelegate(private val key: String)
12. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by IntDelegate("appOpenCount") } class IntDelegate(private val key: String) : ReadWriteProperty<Krate, Int> { }
13. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by IntDelegate("appOpenCount") } class IntDelegate(private val key: String) : ReadWriteProperty<Krate, Int> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): Int { } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: Int) { } }
14. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by IntDelegate("appOpenCount") } class IntDelegate(private val key: String) : ReadWriteProperty<Krate, Int> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): Int { } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: Int) { } }
15. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount: Int by IntDelegate("appOpenCount") } class IntDelegate(private val key: String) : ReadWriteProperty<Krate, Int> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): Int { } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: Int) { } }
16. Krate class IntDelegate(private val key: String) : ReadWriteProperty<Krate, Int> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): Int { } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: Int) { } } class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by IntDelegate("appOpenCount") }
17. Krate class IntDelegate(private val key: String) : ReadWriteProperty<Krate, Int> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): Int { return thisRef.sharedPreferences.getInt(key, 0) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: Int) { thisRef.sharedPreferences.edit().putInt(key, value).apply() } } class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by IntDelegate("appOpenCount") }
18. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by IntDelegate("appOpenCount") } class IntDelegate(private val key: String) : ReadWriteProperty<Krate, Int> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): Int { return thisRef.sharedPreferences.getInt(key, 0) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: Int) { thisRef.sharedPreferences.edit().putInt(key, value).apply() } } fun Krate.intPref(key: String): ReadWriteProperty<Krate, Int> { return IntDelegate(key) }
19. Krate class MyKrate(context: Context) : SimpleKrate(context) { var appOpenCount by intPref("appOpenCount") } class IntDelegate(private val key: String) : ReadWriteProperty<Krate, Int> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): Int { return thisRef.sharedPreferences.getInt(key, 0) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: Int) { thisRef.sharedPreferences.edit().putInt(key, value).apply() } } fun Krate.intPref(key: String): ReadWriteProperty<Krate, Int> { return IntDelegate(key) }
20. Krate AutSoft/Krate
21. Moshi square/moshi
22. Moshi
23. Moshi › Gson v3 in everything but name
24. Moshi › Gson v3 in everything but name › Part of the Ok libraries Okio Retrofit OkHttp Moshi
25. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API Okio Retrofit OkHttp Moshi
26. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API
27. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values
28. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String, )
29. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String, ) val moshi = Moshi.Builder().build()
30. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String, ) val moshi = Moshi.Builder().build() val burgerAdapter = moshi.adapter(Burger::class.java)
31. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String, ) val moshi = Moshi.Builder().build() val burgerAdapter = moshi.adapter(Burger::class.java) val burger = burgerAdapter.fromJson( "{\"name\": \"Cheeseburger\"}" )
32. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String, ) val moshi = Moshi.Builder().build() val burgerAdapter = moshi.adapter(Burger::class.java) val burger = burgerAdapter.fromJson( "{\"name\": \"Cheeseburger\"}" ) Exception in thread "main" com.squareup.moshi.JsonDataException: Required value 'description' missing at $
33. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String?, ) val moshi = Moshi.Builder().build() val burgerAdapter = moshi.adapter(Burger::class.java) val burger = burgerAdapter.fromJson( "{\"name\": \"Cheeseburger\"}" )
34. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String ) val moshi = Moshi.Builder().build() val burgerAdapter = moshi.adapter(Burger::class.java) val burger = burgerAdapter.fromJson( "{\"name\": \"Cheeseburger\"}" ) Burger(name=Cheeseburger, description=null) ?,
35. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String ) val moshi = Moshi.Builder().build() val burgerAdapter = moshi.adapter(Burger::class.java) val burger = burgerAdapter.fromJson( "{\"name\": \"Cheeseburger\"}" ) › Default parameter values ?,
36. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values val moshi = Moshi.Builder().build() val burgerAdapter = moshi.adapter(Burger::class.java) val burger = burgerAdapter.fromJson( "{\"name\": \"Cheeseburger\"}" ) @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String ) , = "Yummy!"
37. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values val moshi = Moshi.Builder().build() val burgerAdapter = moshi.adapter(Burger::class.java) val burger = burgerAdapter.fromJson( "{\"name\": \"Cheeseburger\"}" ) Burger(name=Cheeseburger, description=Yummy!) @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String ) , = "Yummy!"
38. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values › Codegen, reflection, or both @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String = "Yummy!", ) val moshi = Moshi.Builder().build()
39. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values › Codegen, reflection, or both data class Burger( val name: String, val description: String = "Yummy!", ) val moshi = Moshi.Builder().build()
40. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values › Codegen, reflection, or both data class Burger( val name: String, val description: String = "Yummy!", ) val moshi = Moshi.Builder() .add(KotlinJsonAdapterFactory()) .build()
41. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values › Codegen, reflection, or both @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String = "Yummy!", ) val moshi = Moshi.Builder() .add(KotlinJsonAdapterFactory()) .build()
42. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values › Codegen, reflection, or both › Always calls constructors @JsonClass(generateAdapter = true) data class Burger( val name: String, val description: String = "Yummy!", ) { init { println("$name coming up...") } }
43. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values › Always calls constructors › Named after Jake’s dog › Codegen, reflection, or both
44. Moshi › Gson v3 in everything but name › Part of the Ok libraries › Streaming API › Nullable values › Default parameter values › Always calls constructors › Named after Jake’s dog › Codegen, reflection, or both
45. Storing complex data
46. DISCLAIMER Consider using a database before storing data like this in SharedPreferences
47. Gson delegate
48. Gson delegate fun <T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key) }
49. Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> fun <T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key) }
50. Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { } } fun <T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key) }
51. Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<T>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { } } fun <T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key) }
52. Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<T>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } fun <T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key) }
53. Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<T>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } fun <T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key) } java.lang.ClassCastException: com.google.gson.internal.LinkedTreeMap cannot be cast to hu.autsoft.krate.gson.TestModel
54. Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<T>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } fun <T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key) }
55. Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<T>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } fun <T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key) }
56. Gson delegate class GsonDelegate<Object>( private val key: String, ) : ReadWriteProperty<Krate, Object> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): Object? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<Object>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: Object?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } fun <Object> Krate.gsonPref(key: String): ReadWriteProperty<Krate, Object?> { return GsonDelegate(key) }
57. Object T Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<T>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } inline fun <reified T : Any> ?> { return GsonDelegate(key) } Krate.gsonPref(key: String): ReadWriteProperty<Krate,
58. inline fun <reified T : Any> ?> { return GsonDelegate(key) } Object T Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<T>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } Krate.gsonPref(key: String): ReadWriteProperty<Krate,
59. Gson delegate class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, object : TypeToken<T>() {}.type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } inline fun <reified T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key, object : TypeToken<T>() {}.type) }
60. inline fun <reified T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key, object : TypeToken<T>() {}.type) } Gson delegate } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } class GsonDelegate<T : Any>( private val key: String, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, ) private val type: Type, type
61. Testing Krate
62. Gson delegate tests data class TestModel(val x: Int, val y: Double, val z: String)
63. Gson delegate tests class GsonTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by gsonPref("simpleValue") var listOfValues: List<TestModel>? by gsonPref("listOfValues") } data class TestModel(val x: Int, val y: Double, val z: String)
64. Gson delegate tests class GsonTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by gsonPref("simpleValue") var listOfValues: List<TestModel>? by gsonPref("listOfValues") } data class TestModel(val x: Int, val y: Double, val z: String) val krate = GsonTestKrate(targetContext)
65. Gson delegate tests class GsonTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by gsonPref("simpleValue") var listOfValues: List<TestModel>? by gsonPref("listOfValues") } @Test fun testSimpleValue() { val model = TestModel(x = 42, y = 3.141592, z = "shibboleth") krate.simpleValue = model assertEquals(model, krate.simpleValue) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = GsonTestKrate(targetContext)
66. Gson delegate tests class GsonTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by gsonPref("simpleValue") var listOfValues: List<TestModel>? by gsonPref("listOfValues") } @Test fun testSimpleValue() { val model = TestModel(x = 42, y = 3.141592, z = "shibboleth") krate.simpleValue = model assertEquals(model, krate.simpleValue) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = GsonTestKrate(targetContext)
67. Gson delegate tests class GsonTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by gsonPref("simpleValue") var listOfValues: List<TestModel>? by gsonPref("listOfValues") } @Test fun testListOfValues() { val list = listOf( TestModel(x = 42, y = 3.141592, z = "shibboleth"), TestModel(x = 13, y = 6.283185, z = "signal"), ) krate.listOfValues = list assertEquals(list, krate.listOfValues) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = GsonTestKrate(targetContext)
68. Gson delegate tests class GsonTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by gsonPref("simpleValue") var listOfValues: List<TestModel>? by gsonPref("listOfValues") } @Test fun testListOfValues() { val list = listOf( TestModel(x = 42, y = 3.141592, z = "shibboleth"), TestModel(x = 13, y = 6.283185, z = "signal"), ) krate.listOfValues = list assertEquals(list, krate.listOfValues) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = GsonTestKrate(targetContext)
69. ft Krate Moshi
70. class GsonDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val gson = Gson() val string = thisRef.sharedPreferences.getString(key, null) return gson.fromJson(string, type) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } } inline fun <reified T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key, object : TypeToken<T>() {}.type) } Moshi delegate
71. inline fun <reified T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key, object : TypeToken<T>() {}.type) } Moshi delegate gson Gson() = .fromJson(string ) , type gson class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val val string = thisRef.sharedPreferences.getString(key, null) return } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } }
72. inline fun <reified T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key, object : TypeToken<T>() {}.type) } Moshi delegate moshi.adapter<T?>(type) = adapter .fromJson(string) adapter class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val val string = thisRef.sharedPreferences.getString(key, null) return } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val gson = Gson() thisRef.sharedPreferences.edit() .putString(key, gson.toJson(value)) .apply() } }
73. class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val adapter = moshi.adapter<T?>(type) val string = thisRef.sharedPreferences.getString(key, null) return adapter.fromJson(string) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val adapter = moshi.adapter<T?>(type) thisRef.sharedPreferences.edit() .putString(key, adapter.toJson(value)) .apply() } } inline fun <reified T : Any> Krate.gsonPref(key: String): ReadWriteProperty<Krate, T?> { return GsonDelegate(key, object : TypeToken<T>() {}.type) } Moshi delegate
74. class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val adapter = moshi.adapter<T?>(type) val string = thisRef.sharedPreferences.getString(key, null) return adapter.fromJson(string) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val adapter = moshi.adapter<T?>(type) thisRef.sharedPreferences.edit() .putString(key, adapter.toJson(value)) .apply() } } inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, object : TypeToken<T>() {}.type) } Moshi delegate
75. class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val adapter = moshi.adapter<T?>(type) val string = thisRef.sharedPreferences.getString(key, null) return adapter.fromJson(string) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val adapter = moshi.adapter<T?>(type) thisRef.sharedPreferences.edit() .putString(key, adapter.toJson(value)) .apply() } } inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, object : TypeToken<T>() {}.type) } Moshi delegate
76. inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, } class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { override operator fun getValue(thisRef: Krate, property: KProperty<*>): T? { val adapter = moshi.adapter<T?>(type) val string = thisRef.sharedPreferences.getString(key, null) return adapter.fromJson(string) } override operator fun setValue(thisRef: Krate, property: KProperty<*>, value: T?) { val adapter = moshi.adapter<T?>(type) thisRef.sharedPreferences.edit() .putString(key, adapter.toJson(value)) .apply() } } Moshi delegate ???)
77. Class
78. java.lang.Class
79. java.lang.Class classes and interfaces in a running Java application
80. java.lang.Class classes and interfaces in a running Java application Class c1 = object.getClass();
81. java.lang.Class classes and interfaces in a running Java application Class c1 = object.getClass(); any.javaClass // Kotlin
82. java.lang.Class classes and interfaces in a running Java application Class c1 = object.getClass(); Class c2 = String.class; any.javaClass // Kotlin
83. java.lang.Class classes and interfaces in a running Java application Class c1 = object.getClass(); Class c2 = String.class; any.javaClass "hello world".getClass(); // class java.lang.String new ArrayList<String>().getClass(); // class java.util.ArrayList new Serializable() {}.getClass(); // class com.example.Main$1 // Kotlin
84. java.lang.Class classes and interfaces in a running Java application Class c1 = object.getClass(); Class c2 = String.class; any.javaClass c.getName(); c.getSimpleName(); c.getCanonicalName(); c.getTypeName(); // Kotlin [I int[] int[] int[] java.lang.String String java.lang.String java.lang.String com.example.Main$1 null com.example.Main$1
85. java.lang.Class classes and interfaces in a running Java application Class c1 = object.getClass(); Class c2 = String.class; any.javaClass c.getName(); c.getSimpleName(); c.getCanonicalName(); c.getTypeName(); Annotation[] annotations = c.getAnnotations(); Class[] interfaces = c.getInterfaces(); Constructor[] constructors = c.getConstructors(); Field[] fields = c.getFields(); Method[] methods = c.getMethods(); // Kotlin [I int[] int[] int[] java.lang.String String java.lang.String java.lang.String com.example.Main$1 null com.example.Main$1
86. java.lang.reflect.Type
87. java.lang.reflect.Type all types in the Java programming language - raw types - parameterized types - array types - type variables - primitive types
88. java.lang.reflect.Type all types in the Java programming language - raw types - parameterized types - array types - type variables - primitive types String getTypeName();
89. java.lang.reflect.Type all types in the Java programming language - raw types - parameterized types - array types - type variables - primitive types Class String getTypeName();
90. java.lang.reflect.Type all types in the Java programming language - raw types - parameterized types - array types - type variables - primitive types Class ParameterizedType Type getRawType(); Type[] getActualTypeArguments(); String getTypeName();
91. Class Type No generics Supports generics Java reflection
92. Class Type No generics Supports generics Java reflection Kotlin reflection
93. Class Type No generics Supports generics Java reflection Kotlin reflection KClass
94. kotlin.reflect.KClass
95. kotlin.reflect.KClass val k1: KClass<*> = any::class val k2: KClass<*> = String::class
96. kotlin.reflect.KClass val simpleName: String? val qualifiedName: String? val members: Collection<KCallable<*>> val constructors: Collection<KFunction<T>> val nestedClasses: Collection<KClass<*>> val typeParameters: List<KTypeParameter> val supertypes: List<KType> val sealedSubclasses: List<KClass<out T>> val visibility: KVisibility? val k1: KClass<*> = any::class val k2: KClass<*> = String::class
97. kotlin.reflect.KClass val k1: KClass<*> = any::class val k2: KClass<*> = String::class val isFinal: Boolean val isOpen: Boolean val isAbstract: Boolean val isSealed: Boolean val isData: Boolean val isInner: Boolean val isCompanion: Boolean val isFun: Boolean
98. val c: Class<*> = String::class.java kotlin.reflect.KClass val k1: KClass<*> = any::class val k2: KClass<*> = String::class
99. val c: Class<*> = String::class.java kotlin.reflect. val k1: KClass<*> = any::class val k2: KClass<*> = String::class String.class // Java // Kotlin KClass
100. Class Type No generics Supports generics Java reflection Kotlin reflection KClass
101. Class Type No generics Supports generics Java reflection Kotlin reflection KClass KType ParameterizedType
102. Class Type No generics Supports generics Java reflection Kotlin reflection KClass KType ParameterizedType
103. Class Type No generics Supports generics Java reflection Kotlin reflection KClass KType rawType actualTypeArguments ParameterizedType
104. Class Type No generics Supports generics Java reflection Kotlin reflection KClass KType rawType actualTypeArguments ParameterizedType classifier arguments
105. rawType actualTypeArguments ParameterizedType classifier arguments isMarkedNullable Class Type No generics Supports generics Java reflection Kotlin reflection KClass KType
106. rawType actualTypeArguments ParameterizedType classifier arguments Class Type No generics Supports generics Java reflection Kotlin reflection KClass KType
107. Looking for a Type inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, ???) } class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { ... }
108. Looking for a Type inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { ... }
109. Looking for a Type inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } class MoshiDelegate<T : Any>( private val key: String, private val type: Type, ) : ReadWriteProperty<Krate, T?> { ... }
110. Moshi delegate tests class GsonTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by gsonPref("simpleValue") var listOfValues: List<TestModel>? by gsonPref("listOfValues") } @Test fun testSimpleValue() { val model = TestModel(x = 42, y = 3.141592, z = "shibboleth") krate.simpleValue = model assertEquals(model, krate.simpleValue) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = GsonTestKrate(targetContext)
111. Moshi delegate tests class MoshiTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by moshiPref("simpleValue") var listOfValues: List<TestModel>? by moshiPref("listOfValues") } @Test fun testSimpleValue() { val model = TestModel(x = 42, y = 3.141592, z = "shibboleth") krate.simpleValue = model assertEquals(model, krate.simpleValue) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = GsonTestKrate(targetContext)
112. Moshi delegate tests class MoshiTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by moshiPref("simpleValue") var listOfValues: List<TestModel>? by moshiPref("listOfValues") } @Test fun testSimpleValue() { val model = TestModel(x = 42, y = 3.141592, z = "shibboleth") krate.simpleValue = model assertEquals(model, krate.simpleValue) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = MoshiTestKrate(targetContext)
113. Moshi delegate tests class MoshiTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by moshiPref("simpleValue") var listOfValues: List<TestModel>? by moshiPref("listOfValues") } @Test fun testSimpleValue() { val model = TestModel(x = 42, y = 3.141592, z = "shibboleth") krate.simpleValue = model assertEquals(model, krate.simpleValue) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = MoshiTestKrate(targetContext)
114. Moshi delegate tests class MoshiTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by moshiPref("simpleValue") var listOfValues: List<TestModel>? by moshiPref("listOfValues") } @Test fun testListOfValues() { val list = listOf( TestModel(x = 42, y = 3.141592, z = "shibboleth"), TestModel(x = 13, y = 6.283185, z = "signal"), ) krate.listOfValues = list assertEquals(list, krate.listOfValues) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = MoshiTestKrate(targetContext)
115. Moshi delegate tests class MoshiTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by moshiPref("simpleValue") var listOfValues: List<TestModel>? by moshiPref("listOfValues") } @Test fun testListOfValues() { val list = listOf( TestModel(x = 42, y = 3.141592, z = "shibboleth"), TestModel(x = 13, y = 6.283185, z = "signal"), ) krate.listOfValues = list assertEquals(list, krate.listOfValues) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = MoshiTestKrate(targetContext)
116. class MoshiTestKrate(context: Context) : SimpleKrate(context) { var simpleValue: TestModel? by moshiPref("simpleValue") var listOfValues: List<TestModel>? by moshiPref("listOfValues") } @Test fun testListOfValues() { val list = listOf( TestModel(x = 42, y = 3.141592, z = "shibboleth"), TestModel(x = 13, y = 6.283185, z = "signal"), ) krate.listOfValues = list assertEquals(list, krate.listOfValues) } data class TestModel(val x: Int, val y: Double, val z: String) val krate = MoshiTestKrate(targetContext) Moshi delegate tests java.lang.AssertionError: Expected :[ TestModel(x=42, y=3.141592, z=shibboleth), TestModel(x=13, y=6.283185, z=signal) ] Actual :[ {x=42.0, y=3.141592, z=shibboleth}, {x=13.0, y=6.283185, z=signal} ]
117. java.lang.AssertionError: Expected :[ TestModel(x=42, y=3.141592, z=shibboleth), TestModel(x=13, y=6.283185, z=signal) ] Actual :[ {x=42.0, y=3.141592, z=shibboleth}, {x=13.0, y=6.283185, z=signal} ]
118. Actual :[ {x=42.0, y=3.141592, z=shibboleth}, {x=13.0, y=6.283185, z=signal} ]
119. inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } Moshi delegate tests
120. inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } Moshi delegate tests
121. inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } Moshi delegate tests
122. var simpleValue by moshiPref<TestModel>("simpleValue") var listOfValues by moshiPref<List<TestModel>>("listOfValues") inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } Moshi delegate tests
123. var simpleValue by moshiPref<TestModel>("simpleValue") var listOfValues by moshiPref<List<TestModel>>("listOfValues") inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } class hu.autsoft.krate.moshi.TestModel Moshi delegate tests
124. class hu.autsoft.krate.moshi.TestModel interface java.util.List var simpleValue by moshiPref<TestModel>("simpleValue") var listOfValues by moshiPref<List<TestModel>>("listOfValues") inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } Moshi delegate tests
125. inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } Looking for a Type
126. inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } Types.newParameterizedType(List::class.java, TestModel::class.java) Looking for a Type
127. inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, T::class.java) } Types.newParameterizedType(List::class.java, TestModel::class.java) java.util.List<hu.autsoft.krate.moshi.TestModel> Looking for a Type
128. inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate( key, Types.newParameterizedType(T::class.java, ???::class.java) ) } Types.newParameterizedType(List::class.java, TestModel::class.java) java.util.List<hu.autsoft.krate.moshi.TestModel> Looking for a Type
129. Looking for a Type inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, } ) ???
130. Looking for a Type inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, object : TypeToken<T>() {}.type) }
131. TypeToken object : TypeToken<T>() {}.type
132. TypeToken public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass.getGenericSuperclass(); if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return canonicalize(parameterized.getActualTypeArguments()[0]); } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... } } object : TypeToken<T>() {}.type
133. TypeToken public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass.getGenericSuperclass(); if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return canonicalize(parameterized.getActualTypeArguments()[0]); } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... } } object : TypeToken<T>() {}.type
134. TypeToken public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass.getGenericSuperclass(); if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return canonicalize(parameterized.getActualTypeArguments()[0]); } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... } } object : TypeToken<T>() {}.type
135. TypeToken public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass.getGenericSuperclass(); if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return canonicalize(parameterized.getActualTypeArguments()[0]); } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... } } object : TypeToken<T>() {}.type
136. TypeToken public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass. if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return canonicalize(parameterized.getActualTypeArguments()[0]); } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... } } object : TypeToken<T>() {}.type getGenericSuperclass();
137. getGenericSuperclass(); * ... */ public Type /** * Returns the Type representing the direct superclass of the entity * represented by this Class. *
138. * If the superclass is a parameterized type, the Type object returned must * accurately reflect the actual type parameters used in the source code. * getGenericSuperclass(); * ... */ public Type /** * Returns the Type representing the direct superclass of the entity * represented by this Class. *
139. * Non-parameterized -> Class * Parameterized -> ParameterizedType * If the superclass is a parameterized type, the Type object returned must * accurately reflect the actual type parameters used in the source code. * getGenericSuperclass(); * ... */ public Type /** * Returns the Type representing the direct superclass of the entity * represented by this Class. *
140. TypeToken public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass. if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return canonicalize(parameterized.getActualTypeArguments()[0]); } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... } } object : TypeToken<T>() {}.type getGenericSuperclass();
141. TypeToken public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass.getGenericSuperclass(); if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return canonicalize(parameterized.getActualTypeArguments()[0]); } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... } } object : TypeToken<T>() {}.type
142. TypeToken public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass.getGenericSuperclass(); if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return canonicalize(parameterized.getActualTypeArguments()[0]); } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... } } object : TypeToken<T>() {}.type
143. TypeToken object : TypeToken<T>() {}.type public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass.getGenericSuperclass(); if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; parameterized.getActualTypeArguments()[0] canonicalize( ); return } } /** * Returns a type that is functionally equal but not necessarily equal * according to Object.equals(). */ public static Type canonicalize(Type type) { ... }
144. parameterized.getActualTypeArguments()[0] TypeToken object : TypeToken<T>() {}.type ; public class TypeToken<T> { final Type type = getSuperclassTypeParameter(getClass()); protected TypeToken() {} static Type getSuperclassTypeParameter(Class<?> subclass) { Type superclass = subclass.getGenericSuperclass(); if (superclass instanceof Class) { throw new RuntimeException("Missing type parameter."); } ParameterizedType parameterized = (ParameterizedType) superclass; return } }
145. open constructor val fun : * : val is <*> val as getGenericSuperclass() getActualTypeArguments() TypeToken object : TypeToken<T>() {}.type subclass getSuperclassTypeParameter Class< >) Type ( type = getSuperclassTypeParameter( ) class TypeToken<T> { { { } } } return parameterized. parameterized = () protected javaClass if (superclass Class superclass = subclass. ) superclass ParameterizedType RuntimeException("Missing type parameter.") throw [0] actualTypeArguments genericSuperclass
146. : Type requireNotNull token::class.java if (superclass is Class<*>) { throw RuntimeException("Missing type parameter.") } val parameterized = superclass as ParameterizedType return parameterized.actualTypeArguments[0] } TypeToken object : TypeToken<T>() {}.type abstract ): Type { .genericSuperclass ( ) class TypeToken<T> val token = object : TypeToken<T>() {} inline <reified T> makeType = val superclass ( fun
147. TypeToken makeType<T>() : Type requireNotNull token::class.java if (superclass is Class<*>) { throw RuntimeException("Missing type parameter.") } val parameterized = superclass as ParameterizedType return parameterized.actualTypeArguments[0] } abstract ): Type { .genericSuperclass ( ) class TypeToken<T> val token = object : TypeToken<T>() {} inline <reified T> makeType = val superclass ( fun
148. TypeToken inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, ) } makeType<T>() : Type requireNotNull token::class.java if (superclass is Class<*>) { throw RuntimeException("Missing type parameter.") } val parameterized = superclass as ParameterizedType return parameterized.actualTypeArguments[0] } abstract ): Type { .genericSuperclass ( ) class TypeToken<T> val token = object : TypeToken<T>() {} inline <reified T> makeType = val superclass ( fun
149. TypeToken
150. typeOf inline fun <reified T> makeType(): Type inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, makeType<T>()) }
151. typeOf inline fun <reified T> makeType(): Type /** * Returns a runtime representation of the given * reified type [T] as an instance of [KType]. */ inline fun <reified T> typeOf(): KType inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, makeType<T>()) }
152. typeOf inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>()) } /** * Returns a runtime representation of the given * reified type [T] as an instance of [KType]. */ inline fun <reified T> typeOf(): KType
153. typeOf inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>()) } /** * Returns a runtime representation of the given * reified type [T] as an instance of [KType]. */ inline fun <reified T> typeOf(): KType
154. typeOf inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>()) } /** * Returns a runtime representation of the given * reified type [T] as an instance of [KType]. */ inline fun <reified T> typeOf(): KType /** * Returns a Java [Type] instance corresponding * to the given Kotlin type. */ val KType.javaType: Type
155. typeOf inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>().javaType) } /** * Returns a runtime representation of the given * reified type [T] as an instance of [KType]. */ inline fun <reified T> typeOf(): KType /** * Returns a Java [Type] instance corresponding * to the given Kotlin type. */ val KType.javaType: Type
156. typeOf inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>().javaType) } /** * Returns a runtime representation of the given * reified type [T] as an instance of [KType]. */ inline fun <reified T> typeOf(): KType /** * Returns a Java [Type] instance corresponding * to the given Kotlin type. */ val KType.javaType: Type NotImplementedError: Java type is not yet supported for types created with createType
157. typeOf inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>().javaType) } /** * Returns a runtime representation of the given * reified type [T] as an instance of [KType]. */ /** * Returns a Java [Type] instance corresponding * to the given Kotlin type. */ val KType.javaType: Type inline fun <reified T> typeOf(): KType NotImplementedError: Java type is not yet supported for types created with createType
158. makeType typeOf inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>().javaType) } inline fun <reified T> typeOf(): KType val KType.javaType: Type fun KClassifier.createType(...): KType { ... return KTypeImpl(kotlinType) { TODO("Java type is not yet supported for types created with createType") } }
159. typeOf inline fun <reified T> typeOf(): KType val KType.javaType: Type inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, makeType<T>()) }
160. typeOf inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>().javaType) } inline fun <reified T> typeOf(): KType val KType.javaType: Type
161. typeOf @OptIn(ExperimentalStdlibApi::class) inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>().javaType) } inline fun <reified T> typeOf(): KType val KType.javaType: Type
162. typeOf @OptIn(ExperimentalStdlibApi::class) inline fun <reified T : Any> Krate.moshiPref(key: String): ReadWriteProperty<Krate, T?> { return MoshiDelegate(key, typeOf<T>().javaType) } inline fun <reified T> typeOf(): KType val KType.javaType: Type
163. Resources
164. • Krate  https://github.com/AutSoft/Krate • Moshi  https://github.com/square/moshi Resources
165. • Krate  https://github.com/AutSoft/Krate • Moshi  https://github.com/square/moshi • Delightful Delegate Design  https://www.droidcon.com/media-detail?video=481186381 • Say “hi” to Moshi!  https://www.youtube.com/watch?v=qadYVYc-8mc Resources
166. • Krate  https://github.com/AutSoft/Krate • Moshi  https://github.com/square/moshi • Delightful Delegate Design  https://www.droidcon.com/media-detail?video=481186381 • Say “hi” to Moshi!  https://www.youtube.com/watch?v=qadYVYc-8mc • Library design articles  https://zsmb.co/maintaining-compatibility-in-kotlin-libraries/  https://zsmb.co/mastering-api-visibility-in-kotlin/  https://zsmb.co/talks/how-to-build-awesome-android-libraries/ Resources
167. zsmb13 zsmb.co/talks
168. ft Krate Moshi A Kotlin library design case study zsmb.co/talks zsmb13 Márton Braun › Krate is great › Moshi is awesome › Type erasure is evil › Tests are your friend