package com.example.roomdemo
import androidx.databinding.Bindable
import androidx.databinding.Observable
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import com.example.roomdemo.db.Subscriber
import com.example.roomdemo.db.SubscriberRepository
import kotlinx.coroutines.launch
class SubscriberViewModel(private val repository: SubscriberRepository) : ViewModel(),Observable {
val subscribers = repository.subscribers
private var isUpdateOrDelete = false
private lateinit var subscriberToUpdateOrDelete : Subscriber
@Bindable
val inputName = MutableLiveData<String>()
@Bindable
val inputEmail = MutableLiveData<String>()
@Bindable
val saveOrUpdateButtonText = MutableLiveData<String>()
@Bindable
val clearAllOrDeleteButtonText = MutableLiveData<String>()
init {
saveOrUpdateButtonText.value = "Save"
clearAllOrDeleteButtonText.value = "Clear All"
}
fun saveOrUpdate() {
if(isUpdateOrDelete) {
subscriberToUpdateOrDelete.name = inputName.value!!
subscriberToUpdateOrDelete.email = inputEmail.value!!
update(subscriberToUpdateOrDelete)
}else {
val name = inputName.value!!
val email = inputEmail.value!!
insert(Subscriber(0, name, email))
inputName.value = null
inputEmail.value = null
}
}
fun clearAllOrDelete() {
if(isUpdateOrDelete) {
delete(subscriberToUpdateOrDelete)
}else {
clearAll()
}
}
fun insert(subscriber: Subscriber)= viewModelScope.launch {
repository.insert(subscriber)
}
fun update(subscriber: Subscriber) = viewModelScope.launch {
repository.update(subscriber)
inputName.value = null
inputEmail.value = null
isUpdateOrDelete = false
saveOrUpdateButtonText.value = "Save"
clearAllOrDeleteButtonText.value = "Clear All"
}
fun delete(subscriber: Subscriber) = viewModelScope.launch {
repository.delete(subscriber)
inputName.value = null
inputEmail.value = null
isUpdateOrDelete = false
saveOrUpdateButtonText.value = "Save"
clearAllOrDeleteButtonText.value = "Clear All"
}
fun clearAll()=viewModelScope.launch {
repository.deleteAll()
}
fun initUpdateAndDelete(subscriber: Subscriber) {
inputName.value = subscriber.name
inputEmail.value = subscriber.email
isUpdateOrDelete = true
subscriberToUpdateOrDelete = subscriber
saveOrUpdateButtonText.value = "Update"
clearAllOrDeleteButtonText.value = "Delete"
}
override fun removeOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback?) {
}
override fun addOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback?) {
}
}
package com.example.roomdemo
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import androidx.databinding.DataBindingUtil
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProvider
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.roomdemo.databinding.ActivityMainBinding
import com.example.roomdemo.db.Subscriber
import com.example.roomdemo.db.SubscriberDatabase
import com.example.roomdemo.db.SubscriberRepository
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
private lateinit var subscriberViewModel: SubscriberViewModel
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = DataBindingUtil.setContentView(this,R.layout.activity_main)
val dao = SubscriberDatabase.getInstance(application).subscriberDAO
val repository = SubscriberRepository(dao)
val factory = SubscriberViewModelFactory(repository)
subscriberViewModel = ViewModelProvider(this,factory).get(SubscriberViewModel::class.java)
binding.myViewModel = subscriberViewModel
binding.lifecycleOwner = this
initRecyclerView()
}
private fun initRecyclerView() {
binding.subscriberRecyclerView.layoutManager = LinearLayoutManager(this)
displaySubscribersList()
}
private fun displaySubscribersList() {
subscriberViewModel.subscribers.observe(this, Observer {
binding.subscriberRecyclerView.adapter = MyRecyclerViewAdapter(it, {selecteditem:Subscriber->listItemClicked(selecteditem)})
})
}
private fun listItemClicked(subscriber: Subscriber) {
subscriberViewModel.initUpdateAndDelete(subscriber)
}
}
package com.example.roomdemo
import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.databinding.DataBindingUtil
import androidx.recyclerview.widget.RecyclerView
import com.example.roomdemo.databinding.ListItemBinding
import com.example.roomdemo.db.Subscriber
class MyRecyclerViewAdapter(
private val subscribersList: List<Subscriber>,
private val clickListener: (Subscriber) -> Unit
) : RecyclerView.Adapter<MyViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
val layoutInflater = LayoutInflater.from(parent.context)
val binding: ListItemBinding =
DataBindingUtil.inflate(layoutInflater, R.layout.list_item, parent, false)
return MyViewHolder(binding)
}
override fun getItemCount(): Int {
return subscribersList.size
}
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.bind(subscribersList[position], clickListener)
}
}
class MyViewHolder(val binding: ListItemBinding) : RecyclerView.ViewHolder(binding.root) {
fun bind(subscriber: Subscriber, clickListener: (Subscriber) -> Unit) {
binding.nameTextView.text = subscriber.name
binding.emailTextView.text = subscriber.email
binding.listItemLayout.setOnClickListener{
clickListener(subscriber)
}
}
}
package com.example.roomdemo
import androidx.lifecycle.ViewModel
import androidx.lifecycle.ViewModelProvider
import com.example.roomdemo.db.SubscriberRepository
class SubscriberViewModelFactory(private val repository: SubscriberRepository) : ViewModelProvider.Factory {
override fun <T : ViewModel?> create(modelClass: Class<T>): T {
if (modelClass.isAssignableFrom(SubscriberViewModel::class.java)) {
return SubscriberViewModel(repository) as T
}
throw IllegalArgumentException("Unknown View Model class")
}
}
package com.example.roomdemo.db
import androidx.room.ColumnInfo
import androidx.room.Entity
import androidx.room.PrimaryKey
@Entity(tableName = "subscriber_data_table")
data class Subscriber (
@PrimaryKey(autoGenerate = true)
@ColumnInfo(name = "subscriber_name")
var id : Int,
@ColumnInfo(name = "subscriber_id")
var name : String,
@ColumnInfo(name = "subscriber_email")
var email : String
)
package com.example.roomdemo.db
import androidx.lifecycle.LiveData
import androidx.room.*
@Dao
interface SubscriberDAO {
@Insert
suspend fun insertSubscriber(subscriber: Subscriber): Long
@Update
suspend fun updateSubscriber(subscriber: Subscriber)
@Delete
suspend fun deleteSubscriber(subscriber: Subscriber)
@Query("DELETE FROM subscriber_data_table")
suspend fun deleteAll()
@Query("SELECT * FROM subscriber_data_table")
fun getAllSubscribers(): LiveData<List<Subscriber>>
}
package com.example.roomdemo.db
import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase
@Database(entities = [Subscriber::class],version = 1)
abstract class SubscriberDatabase : RoomDatabase() {
abstract val subscriberDAO: SubscriberDAO
companion object {
@Volatile
private var INSTANCE: SubscriberDatabase? = null
fun getInstance(context: Context): SubscriberDatabase {
synchronized(this) {
var instance = INSTANCE
if (instance == null) {
instance = Room.databaseBuilder(
context.applicationContext,
SubscriberDatabase::class.java,
"subscriber_data_database"
).build()
}
return instance
}
}
}
}
package com.example.roomdemo.db
class SubscriberRepository(private val dao : SubscriberDAO) {
val subscribers = dao.getAllSubscribers()
suspend fun insert(subscriber: Subscriber) {
dao.insertSubscriber(subscriber)
}
suspend fun update(subscriber: Subscriber) {
dao.updateSubscriber(subscriber)
}
suspend fun delete(subscriber: Subscriber) {
dao.deleteSubscriber(subscriber)
}
suspend fun deleteAll() {
dao.deleteAll()
}
}
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