Après beaucoup de difficultés, j'ai réussi à résoudre ce problème. Voici ma solution utilisant l' architecture MMVM:
Student.kt
@Entity(tableName = "students")
data class Student(
@NotNull var name: String,
@NotNull var password: String,
var subject: String,
var email: String
) {
@PrimaryKey(autoGenerate = true)
var roll: Int = 0
}
StudentDao.kt
interface StudentDao {
@Insert
fun insertStudent(student: Student) : Long
}
StudentRepository.kt
class StudentRepository private constructor(private val studentDao: StudentDao)
{
fun getStudents() = studentDao.getStudents()
fun insertStudent(student: Student): Single<Long>? {
return Single.fromCallable(
Callable<Long> { studentDao.insertStudent(student) }
)
}
companion object {
// For Singleton instantiation
@Volatile private var instance: StudentRepository? = null
fun getInstance(studentDao: StudentDao) =
instance ?: synchronized(this) {
instance ?: StudentRepository(studentDao).also { instance = it }
}
}
}
StudentViewModel.kt
class StudentViewModel (application: Application) : AndroidViewModel(application) {
var status = MutableLiveData<Boolean?>()
private var repository: StudentRepository = StudentRepository.getInstance( AppDatabase.getInstance(application).studentDao())
private val disposable = CompositeDisposable()
fun insertStudent(student: Student) {
disposable.add(
repository.insertStudent(student)
?.subscribeOn(Schedulers.newThread())
?.observeOn(AndroidSchedulers.mainThread())
?.subscribeWith(object : DisposableSingleObserver<Long>() {
override fun onSuccess(newReturnId: Long?) {
Log.d("ViewModel Insert", newReturnId.toString())
status.postValue(true)
}
override fun onError(e: Throwable?) {
status.postValue(false)
}
})
)
}
}
Dans le fragment:
class RegistrationFragment : Fragment() {
private lateinit var dataBinding : FragmentRegistrationBinding
private val viewModel: StudentViewModel by viewModels()
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
initialiseStudent()
viewModel.status.observe(viewLifecycleOwner, Observer { status ->
status?.let {
if(it){
Toast.makeText(context , "Data Inserted Sucessfully" , Toast.LENGTH_LONG).show()
val action = RegistrationFragmentDirections.actionRegistrationFragmentToLoginFragment()
Navigation.findNavController(view).navigate(action)
} else
Toast.makeText(context , "Something went wrong" , Toast.LENGTH_LONG).show()
//Reset status value at first to prevent multitriggering
//and to be available to trigger action again
viewModel.status.value = null
//Display Toast or snackbar
}
})
}
fun initialiseStudent() {
var student = Student(name =dataBinding.edName.text.toString(),
password= dataBinding.edPassword.text.toString(),
subject = "",
email = dataBinding.edEmail.text.toString())
dataBinding.viewmodel = viewModel
dataBinding.student = student
}
}
J'ai utilisé DataBinding, voici mon XML:
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="student"
type="com.kgandroid.studentsubject.data.Student" />
<variable
name="listener"
type="com.kgandroid.studentsubject.view.RegistrationClickListener" />
<variable
name="viewmodel"
type="com.kgandroid.studentsubject.viewmodel.StudentViewModel" />
</data>
<androidx.core.widget.NestedScrollView
android:id="@+id/nestedScrollview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
tools:context="com.kgandroid.studentsubject.view.RegistrationFragment">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/constarintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:isScrollContainer="true">
<TextView
android:id="@+id/tvRoll"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:gravity="center_horizontal"
android:text="Roll : 1"
android:textColor="@color/colorPrimary"
android:textSize="18sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<EditText
android:id="@+id/edName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="24dp"
android:layout_marginEnd="16dp"
android:ems="10"
android:inputType="textPersonName"
android:text="Name"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@+id/tvRoll" />
<TextView
android:id="@+id/tvName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginEnd="16dp"
android:text="Name:"
android:textColor="@color/colorPrimary"
android:textSize="18sp"
app:layout_constraintBaseline_toBaselineOf="@+id/edName"
app:layout_constraintEnd_toStartOf="@+id/edName"
app:layout_constraintStart_toStartOf="parent" />
<TextView
android:id="@+id/tvEmail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Email"
android:textColor="@color/colorPrimary"
android:textSize="18sp"
app:layout_constraintBaseline_toBaselineOf="@+id/edEmail"
app:layout_constraintEnd_toStartOf="@+id/edEmail"
app:layout_constraintStart_toStartOf="parent" />
<EditText
android:id="@+id/edEmail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="24dp"
android:layout_marginEnd="16dp"
android:ems="10"
android:inputType="textPersonName"
android:text="Name"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@+id/edName" />
<TextView
android:id="@+id/textView6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Password"
android:textColor="@color/colorPrimary"
android:textSize="18sp"
app:layout_constraintBaseline_toBaselineOf="@+id/edPassword"
app:layout_constraintEnd_toStartOf="@+id/edPassword"
app:layout_constraintStart_toStartOf="parent" />
<EditText
android:id="@+id/edPassword"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="24dp"
android:layout_marginEnd="16dp"
android:ems="10"
android:inputType="textPersonName"
android:text="Name"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@+id/edEmail" />
<Button
android:id="@+id/button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginTop="24dp"
android:layout_marginEnd="32dp"
android:background="@color/colorPrimary"
android:text="REGISTER"
android:onClick="@{() -> viewmodel.insertStudent(student)}"
android:textColor="@android:color/background_light"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/edPassword" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>
</layout>
J'ai beaucoup de mal à accomplir cela avec asynctask car l'opération d'insertion et de suppression de pièce doit être effectuée dans un thread séparé. Enfin capable de le faire avec Single
type observable dans RxJava.
Voici les dépendances Gradle pour rxjava:
implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'
implementation 'io.reactivex.rxjava2:rxjava:2.0.3'
int
ou à lalong
place devoid
suite à l'@Insert
opération?