I have model for planning schedule of events.
PlanningEntity Event has PlanningVariable Slot and Slot has two properties FullTimeSlot and RoomSlot.
I hasn't FullTimeSlot and RoomSlot in Event as different PlanningVariables because they are dependent on each other in a complicated way, and I combine it in one variable Slot.
I want to have ShadowVariable with List of Events in FullTimeSlot. And I do it with
Add property FullTimeSlot in Event and CustomShadowVariable for this Property that depends on Slot
Add property List of Event in FullTimeSlot and #InverseRelationShadowVariable(sourceVariableName = "FullTimeSlot") on it
When I run solver I get an exeption
Caused by: java.lang.IllegalArgumentException: The entity (custis.modeus.commonAutoScheduler.model.FullTimeSlot#6c84ad0e) was never added to this ScoreDirector.
Maybe that specific instance is not in the return values of the PlanningSolution's entity members ([EventList, FullTimeSlotList]).
I think it is because of FullTimeSlot #PlanningEntityCollectionProperty clone in solution, but property FullTimeSlot in Slot didn't clone.
But I dont understand how to do this case.
Code on Kotlin.
#PlanningEntity
class Event {
#SerialName("id") #PlanningId
var Id: Long = 0
#ValueRangeProvider(id = "slotRange")
lateinit var SlotList: ArrayList<Slot>
#PlanningVariable(valueRangeProviderRefs = arrayOf("slotRange"), nullable = false)
var Slot: Slot? = null
#CustomShadowVariable(
variableListenerClass = SlotVariableListener::class,
sources = [PlanningVariableReference(variableName = "Slot")]
)
var FullTimeSlot: FullTimeSlot? = null
}
class SlotVariableListener : VariableListener<Event> {
override fun beforeEntityRemoved(scoreDirector: ScoreDirector<*>?, entity: Event?) {
}
override fun afterVariableChanged(scoreDirector: ScoreDirector<*>?, entity: Event?) {
if (entity != null) {
scoreDirector!!.beforeVariableChanged(entity!!, "FullTimeSlot");
entity!!.FullTimeSlot = entity.Slot?.FullTimeSlot
scoreDirector!!.afterVariableChanged(entity!!, "FullTimeSlot");
}
}
override fun beforeEntityAdded(scoreDirector: ScoreDirector<*>?, entity: Event?) {
}
override fun afterEntityAdded(scoreDirector: ScoreDirector<*>?, entity: Event?) {
}
override fun afterEntityRemoved(scoreDirector: ScoreDirector<*>?, entity: Event?) {
}
override fun beforeVariableChanged(scoreDirector: ScoreDirector<*>?, entity: Event?) {
}
}
Related
I use MVVM and have a list of data elements in a database that is mapped through a DAO and repository to ViewModel functions.
Now, my problem is rather banal; I just want to use the data in fragment variables, but I get a type mismatch.
The MVVM introduces a bit of code, and for completeness of context I'll run through it, but I'll strip it to the essentials:
The data elements are of a data class, "Objects":
#Entity(tableName = "objects")
data class Objects(
#ColumnInfo(name = "object_name")
var objectName: String
) {
#PrimaryKey(autoGenerate = true)
var id: Int? = null
}
In ObjectsDao.kt:
#Dao
interface ObjectsDao {
#Query("SELECT * FROM objects")
fun getObjects(): LiveData<List<Objects>>
}
My database:
#Database(
entities = [Objects::class],
version = 1
)
abstract class ObjectsDatabase: RoomDatabase() {
abstract fun getObjectsDao(): ObjectsDao
companion object {
// create database
}
}
In ObjectsRepository.kt:
class ObjectsRepository (private val db: ObjectsDatabase) {
fun getObjects() = db.getObjectsDao().getObjects()
}
In ObjectsViewModel.kt:
class ObjectsViewModel(private val repository: ObjectsRepository): ViewModel() {
fun getObjects() = repository.getObjects()
}
In ObjectsFragment.kt:
class ObjectsFragment : Fragment(), KodeinAware {
private lateinit var viewModel: ObjectsViewModel
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
viewModel = ViewModelProvider(this, factory).get(ObjectsViewModel::class.java)
// I use the objects in a recyclerview; rvObjectList
rvObjectList.layoutManager = GridLayoutManager(context, gridColumns)
val adapter = ObjectsAdapter(listOf(), viewModel)
// And I use an observer to keep the recyclerview updated
viewModel.getObjects.observe(viewLifecycleOwner, {
adapter.objects = it
adapter.notifyDataSetChanged()
})
}
}
The adapter:
class ObjectsAdapter(var objects: List<Objects>,
private val viewModel: ObjectsViewModel):
RecyclerView.Adapter<ObjectsAdapter.ObjectsViewHolder>() {
// Just a recyclerview adapter
}
Now, all the above works fine - but my problem is that I don't want to use the observer to populate the recyclerview; in the database I store some objects, but there are more objects that I don't want to store.
So, I try to do this instead (in the ObjectsFragment):
var otherObjects: List<Objects>
// ...
if (condition) {
adapter.objects = viewModel.getObjects()
} else {
adapter.objects = otherObjects
}
adapter.notifyDataSetChanged()
And, finally, my problem; I get type mismatch for the true condition assignment:
Type mismatch: inferred type is LiveData<List> but List was expected
I am unable to get my head around this. Isn't this pretty much what is happening in the observer? I know about backing properties, such as explained here, but I don't know how to do that when my data is not defined in the ViewModel.
We need something to switch data source. We pass switching data source event to viewModel.
mySwitch.setOnCheckedChangeListener { _, isChecked ->
viewModel.switchDataSource(isChecked)
}
In viewModel we handle switching data source
(To use switchMap include implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.4.0")
class ObjectsViewModel(private val repository: ObjectsRepository) : ViewModel() {
// Best practice is to keep your data in viewModel. And it is useful for us in this case too.
private val otherObjects = listOf<Objects>()
private val _loadDataFromDataBase = MutableLiveData<Boolean>()
// In case your repository returns liveData of favorite list
// from dataBase replace MutableLiveData(otherObjects) with repository.getFavorite()
fun getObjects() = _loadDataFromDataBase.switchMap {
if (it) repository.getObjects() else MutableLiveData(otherObjects)
}
fun switchDataSource(fromDataBase: Boolean) {
_loadDataFromDataBase.value = fromDataBase
}
}
In activity/fragment observe getObjects()
viewModel.getObjects.observe(viewLifecycleOwner, {
adapter.objects = it
adapter.notifyDataSetChanged()
})
You can do something like this:
var displayDataFromDatabase = true // Choose whatever default fits your use-case
var databaseList = emptyList<Objects>() // List we get from database
val otherList = // The other list that you want to show
toggleSwitch.setOnCheckedChangeListener { _, isChecked ->
displayDataFromDatabase = isChecked // Or the negation of this
// Update adapter to use databaseList or otherList depending upon "isChecked"
}
viewModel.getObjects.observe(viewLifecycleOwner) { list ->
databaseList = list
if(displayDataFromDatabase)
// Update adapter to use this databaseList
}
The Code A is from the project play-billing-samples, you can see it.
I don't know why the author design localCacheBillingClient as lateinit, it cause the code is little complex, if (::localCacheBillingClient.isInitialized == false) {...} are invoked many times.
I think Code B can works well, right?
Code A
class BillingRepository private constructor(private val application: Application) :
PurchasesUpdatedListener, BillingClientStateListener {
lateinit private var localCacheBillingClient: LocalBillingDb
val subsSkuDetailsListLiveData: LiveData<List<AugmentedSkuDetails>> by lazy {
if (::localCacheBillingClient.isInitialized == false) {
localCacheBillingClient = LocalBillingDb.getInstance(application)
}
localCacheBillingClient.skuDetailsDao().getSubscriptionSkuDetails()
}
val inappSkuDetailsListLiveData: LiveData<List<AugmentedSkuDetails>> by lazy {
if (::localCacheBillingClient.isInitialized == false) {
localCacheBillingClient = LocalBillingDb.getInstance(application)
}
localCacheBillingClient.skuDetailsDao().getInappSkuDetails()
}
fun startDataSourceConnections() {
Log.d(LOG_TAG, "startDataSourceConnections")
instantiateAndConnectToPlayBillingService()
localCacheBillingClient = LocalBillingDb.getInstance(application)
}
...
}
Code B
class BillingRepository private constructor(private val application: Application) :
PurchasesUpdatedListener, BillingClientStateListener {
private val localCacheBillingClient: LocalBillingDb by lazy {
LocalBillingDb.getInstance(application)
}
val subsSkuDetailsListLiveData: LiveData<List<AugmentedSkuDetails>> by lazy {
localCacheBillingClient.skuDetailsDao().getSubscriptionSkuDetails()
}
val inappSkuDetailsListLiveData: LiveData<List<AugmentedSkuDetails>> by lazy {
localCacheBillingClient.skuDetailsDao().getInappSkuDetails()
}
fun startDataSourceConnections() {
Log.d(LOG_TAG, "startDataSourceConnections")
instantiateAndConnectToPlayBillingService()
}
...
}
Kotlin - Property initialization using "by lazy" vs. "lateinit"
I believe the answer lies in this thread and precisely below point.
lateinit var can be initialized from anywhere the object is seen from, e.g. from inside a framework code, and multiple initialization scenarios are possible for different objects of a single class. by lazy { ... }, in turn, defines the only initializer for the property, which can be altered only by overriding the property in a subclass. If you want your property to be initialized from outside in a way probably unknown beforehand, use lateinit.
suppose there are 2 classes:
class MyLiveData:LiveData<Int>()
class MyMutableLiveData:MutableLiveData<Int>()
Casting from MutableLiveData to LiveData is permitted:
val ld1=MutableLiveData<Int>()
val ld2:LiveData<Int> = ld1 //ok
But you can't cast your own implementations this way:
val mutable=MyMutableLiveData()
val immutable:MyLiveData = mutable //type missmatch
I understand that MutableLiveData extends LiveData thats why they are castable.But I can't have MyMutableLiveData extending MyLiveData as it won't be mutable in this case
Are there any workarounds?
UPD:I guess I need to show motivation of extending LiveData.I'm trying to implement MutableLiveDataCollection which notifies not just value changes via setValue/postValue but also value modification like adding new elements.I'm surprised there is no native solution for this.
Anyway to obseve modify events there have to be additional observe method.And this method have to be inside immutable part aka LiveDataCollection because views will call it.Inheritance is natural solution here IMHO.
The key idea sits in the MutableLiveData class.The only thing this class does - is it changes access modifiers on setValue/postValue methods.I can do the same trick.Therefore the final code will be:
open class LiveDataCollection<K,
L:MutableCollection<K>,
M:Collection<K>>: LiveData<L>() {
private var active=false
private var diffObservers = ArrayList<Observer<M>>()
fun observe(owner: LifecycleOwner, valueObserver: Observer<L>, diffObserver: Observer<M>) {
super.observe(owner,valueObserver)
diffObservers.add(diffObserver)
}
protected open fun addItems(toAdd:M) {
value?.addAll(toAdd)
if (active)
for (observer in diffObservers)
observer.onChanged(toAdd)
}
override fun removeObservers(owner: LifecycleOwner) {
super.removeObservers(owner)
diffObservers= ArrayList()
}
override fun onActive() {
super.onActive()
active=true
}
override fun onInactive() {
super.onInactive()
active=false
}
}
class MutableLiveDataCollection<K,L:MutableCollection<K>,
M:Collection<K>>: LiveDataCollection<K,L,M>() {
public override fun addItems(toAdd:M) {
super.addItems(toAdd)
}
public override fun postValue(value: L) {
super.postValue(value)
}
public override fun setValue(value: L) {
super.setValue(value)
}
}
I have a tornadoFX application following the MVVM pattern with the model:
data class Person (
val name: String,
val cars: List<Car>
)
data class Car (
val brand: String,
val model: String
)
The application defines the following view:
There is a list-view that lists all persons. Besides the listView is a details-view with a text-field for the person´s name and a table-view for the person´s cars.
A double click on a car entry in the table opens a dialog, in which one can edit the car´s properties.
I want, that if I open the car-details and edit an entry, the changes will be reflected in the table-view. Since i can´t alter the Car-model (which is an immutable type) by adding fx-properties, i came up with the following view-model:
class PersonViewModel(): ItemViewModel<Person> {
val name = bind(Person::name)
val cars = bind { SimpleListProperty<CarViewModel>(item?.cars?.map{CarViewModel(it)}?.observable()) }
override fun onCommit {
// create new person based on ViewModel and store it
}
}
class CarViewModel(item: Car): ItemViewModel<Car> {
val brand = bind(Car::name)
val model = bind(Car::model)
init {
this.item = item
}
}
This way, if double-click on a car-entry in the table-view and open the car-detail-view, an update on the car will be directly reflected in the table-view.
My Problem here is, that I can´t find a way to bind the dirty properties of all my CarViewModels in the table to the PersonViewModel. So if I change a car, the PersonViewModel is not marked as dirty.
Is there a way to bind the dirty-properties of PersonViewModel and CarViewModel? (And also rebind them, if another person is selected).
Or is there even a better way to define my view-models?
I've made a change to the framework to allow ViewModel bindings towards lists to observe ListChange events. This enables you to trigger the dirty state of a list property by altering the list somehow. Merely changing a property inside an item in the list will not trigger it, so in the following example I just get the index of the Car before committing, and reassigning the Car to the same index. This will trigger a ListChange event, which the framework now listens for.
The important action happens in the Car dialog save function:
button("Save").action {
val index = person.cars.indexOf(car.item)
car.commit {
person.cars[index] = car.item
close()
}
}
The index of the car is recorded before the values are committed (to make sure that equals/hashCode matches the same entry), then the newly committed item is inserted in the same index, thus triggering a change event on the list.
Here is a complete example, using mutable JavaFX properties, since they are the idiomatic JavaFX way. You can pretty easily adapt it to using immutable items, or use wrappers.
class Person(name: String, cars: List<Car>) {
val nameProperty = SimpleStringProperty(name)
var name by nameProperty
val carsProperty = SimpleListProperty<Car>(FXCollections.observableArrayList(cars))
var cars by carsProperty
}
class PersonModel : ItemViewModel<Person>() {
val name = bind(Person::nameProperty)
val cars: SimpleListProperty<Car> = bind(Person::carsProperty)
}
class Car(brand: String, model: String) {
val brandProperty = SimpleStringProperty(brand)
var brand by brandProperty
val modelProperty = SimpleStringProperty(model)
var model by modelProperty
}
class CarModel(car: Car? = null) : ItemViewModel<Car>(car) {
val brand = bind(Car::brandProperty)
val model = bind(Car::modelProperty)
}
class DataController : Controller() {
val people = FXCollections.observableArrayList<Person>()
init {
people.add(
Person("Person 1", listOf(Car("BMW", "M3"), Car("Ford", "Fiesta")))
)
}
}
class PersonMainView : View() {
val data: DataController by inject()
val selectedPerson: PersonModel by inject()
override val root = borderpane {
center {
tableview(data.people) {
column("Name", Person::nameProperty)
bindSelected(selectedPerson)
}
}
right(PersonEditor::class)
}
}
class PersonEditor : View() {
val person: PersonModel by inject()
val selectedCar : CarModel by inject()
override val root = form {
fieldset {
field("Name") {
textfield(person.name).required()
}
field("Cars") {
tableview(person.cars) {
column("Brand", Car::brandProperty)
column("Model", Car::modelProperty)
bindSelected(selectedCar)
onUserSelect(2) {
find<CarEditor>().openModal()
}
}
}
button("Save") {
enableWhen(person.dirty)
action {
person.commit()
}
}
}
}
}
class CarEditor : View() {
val car: CarModel by inject()
val person: PersonModel by inject()
override val root = form {
fieldset {
field("Brand") {
textfield(car.brand).required()
}
field("Model") {
textfield(car.model).required()
}
button("Save").action {
val index = person.cars.indexOf(car.item)
car.commit {
person.cars[index] = car.item
close()
}
}
}
}
}
The feature is available in TornadoFX 1.7.17-SNAPSHOT.
I have a class that writes a user to SharedPreferences every time it is set:
class UserManager #Inject constructor(
val prefs: SharedPreferences,
val jsonAdapter: JsonAdapter<User>
) {
companion object {
val USER = "user"
}
var user: User = User()
set(value) {
field = value
prefs.edit().putString(USER, jsonAdapter.toJson(user)).apply()
}
init {
val userString = prefs.getString(USER, null)
if (userString != null) {
user = jsonAdapter.fromJson(userString)
}
}
}
Problem: If the user is set in the init block, it calls the setter and writes the user that we just got from the shared prefs... to the shared prefs.
Question 1: How can I directly set the property from the init block?
Question 2: Why do I have to initialize the User when I define a custom setter, but can omit the initialization when the default setter is used?
You need to directily initiliaze the property with the correct value. You can do this using the run function from the stdlib:
class UserManager #Inject constructor(
val prefs: SharedPreferences,
val jsonAdapter: JsonAdapter<User>
) {
companion object {
val USER = "user"
}
var user: User = run {
val userString = prefs.getString(USER, null)
if (userString != null) {
jsonAdapter.fromJson(userString)
} else {
User()
}
}
set(value) {
field = value
prefs.edit().putString(USER, jsonAdapter.toJson(user)).apply()
}
}
Shorter syntax proposed by Ilya Ryzhenkov on the Kotlin Slack:
var user: User = prefs.getString(USER, null)?.let { jsonAdapter.fromJson(it) } ?: User()
set(value) {
field = value
prefs.edit().putString(USER, jsonAdapter.toJson(user)).apply()
}
I believe the best solution is to use the 'backing property' concept described here: https://kotlinlang.org/docs/reference/properties.html#backing-properties
private var _table: Map<String, Int>? = null
public val table: Map<String, Int>
get() {
if (_table == null)
_table = HashMap() // Type parameters are inferred
return _table ?: throw AssertionError("Set to null by another thread")
}
Then initialize the backing property in the constructor and do <backingproperty> = value instead of field = value as well as point the getter to the backing property.
Take a look at by map delegate, seems like this is the pattern you want:
class User(val map: MutableMap<String, Any?>) {
var name: String by map
var age: Int by map
}
https://kotlinlang.org/docs/reference/delegated-properties.html#storing-properties-in-a-map