I have the feeling that what you actually want is that T should be able to copy itself with a new ID, and have an ID. Not necessarily that it is a data class. So you could just use an interface to define that. For example: interface CopyableWithId<out T> where T: CopyableWithId<T> { fun copy(newId: … Read more
Realm doesn’t support Data classes currently. You can see an example of how to write Realm compatible model classes in Kotlin here: https://github.com/realm/realm-java/tree/master/examples/kotlinExample/src/main/kotlin/io/realm/examples/kotlin/model public open class Person( @PrimaryKey public open var name: String = “”, public open var age: Int = 0, public open var dog: Dog? = null, public open var cats: RealmList<Cat> = … Read more
You can’t use generics with class, as easily observable here: List<Int>::class.java It gives you the same error. To use the generic typ in GSON deserialization, do what is suggested here: https://stackoverflow.com/a/5554296/8073652 EDIT: In Kotlin it looks like this: val type: Type = object : TypeToken<ServiceCall<SurveyListModel>>() {}.type Gson().fromJson<ServiceCall<SurveyListModel>>(json, type).result Here’s a small proof of concept, I’ve … Read more
The problem here is that Kotlin loads the Java class Entity first and it sees getId as a function, not as a getter of some property. A property getter in a Kotlin class cannot override a function, so the property id is not bound as an implementation of the getId function. To workaround this, you … Read more
To fix the problem I moved the model classes to model package and added new ProGuard rule for the package. -keep class com.company.myfeature.model.** { *; } Another solution would be to use @Keep annotation from support library to disable the obfuscation for the class: @Keep data class MyRequestBody(val value: String) Using @Keep may cause problems … Read more
I’ve used this approach. data class Person(val id: String, val name: String) { override fun equals(other: Person) = EssentialData(this) == EssentialData(other) override fun hashCode() = EssentialData(this).hashCode() override fun toString() = EssentialData(this).toString().replaceFirst(“EssentialData”, “Person”) } private data class EssentialData(val id: String) { constructor(person: Person) : this(id = person.id) }
Here is a function to read a property from an instance of a class given the property name (throws exception if property not found, but you can change that behaviour): import kotlin.reflect.KProperty1 import kotlin.reflect.full.memberProperties @Suppress(“UNCHECKED_CAST”) fun <R> readInstanceProperty(instance: Any, propertyName: String): R { val property = instance::class.members // don’t cast here to <Any, R>, it … Read more
Options 3 and 4 would result in the class holding messageId twice. Once in the new class and once in its superclass. The solution is to declare but not define the variable in the superclass: sealed class Message { abstract val messageId: String } data class Track(val event: String, override val messageId: String): Message() This … Read more
You need to use Annotation use-site targets since the default for a property declared in the constructor is to target the annotation on the constructor parameter instead of the getter (which will be seen by JavaBeans compliant hosts) when there are multiple options available. Also using a data class might be inappropriate here (see note … Read more
The copy method of Kotlin is not supposed to be a deep copy at all. As explained in the reference doc (https://kotlinlang.org/docs/reference/data-classes.html), for a class such as: data class User(val name: String = “”, val age: Int = 0) the copy implementation would be: fun copy(name: String = this.name, age: Int = this.age) = User(name, … Read more