gastsail

const functions = require('firebase-functions');
const rp = require('request-promise')
var admin = require("firebase-admin");

var serviceAccount = require("./service_key.json");

admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
  databaseURL: "https://melitest-5bc38.firebaseio.com"
});

gastsail

enum class Status {
    SUCCESS,
    ERROR,
    LOADING
}

gastsail

data class Resource<out T>(val status: Status, val data: T?, val message: String?) {

    companion object {
        fun <T> success(data: T?): Resource<T> {
            return Resource(Status.SUCCESS, data, null)
        }

        fun <T> error(msg: String, data: T?): Resource<T> {
            return Resource(Status.ERROR, data, msg)
        }

gastsail

class MainActivity : AppCompatActivity() {

    private val viewModel by lazy { ViewModelProviders.of(this,MainViewModelFactory(UserUseCase())).get(MainViewModel::class.java) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        observeForUserDetails("Gaston")
    }

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class MainViewModel(private val useCase: UserUseCase) : ViewModel() {

    fun retrieveUserData(userId:String):LiveData<Resource<String>> {
        val userData = MutableLiveData<Resource<String>>()
        useCase.retrieveUserData(userId).observeForever {
            userData.postValue(it)
        }
        return userData
    }
}

gastsail

class UserUseCase {

    private val userDao = UserDao()
    fun retrieveUserData(userId:String): LiveData<Resource<String>> {
        return userDao.getUserName(userId)
    }
}

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class UserDao {

    fun getUserName(userId:String): LiveData<Resource<String>> {
        var userName = MutableLiveData<Resource<String>>()
        FirebaseFirestore.getInstance()
            .collection("users")
            .document(userId)
            .get()
            .addOnSuccessListener {
                userName.value = Resource.success(it.getString("name"))

gastsail

<uses-permission android:name="android.permission.INTERNET"/>

gastsail

fun postEventData(email:String,name:String,surname:String,dollarqty:Int):LiveData<Resource<Boolean>>{
        val datastatus = MutableLiveData<Resource<Boolean>>()
        val userData = User(email,name,surname,dollarqty)
        FirebaseFirestore.getInstance()
            .collection("purchases")
            .add(userData)
            .addOnCompleteListener {
                if(it.isSuccessful) datastatus.value = Resource.success(true)
            }.addOnFailureListener {
                datastatus.value = Resource.error(it.message!!,false)

gastsail

exports.onItemCreation = functions.firestore.document('purchases/{purchaseId}')
 .onCreate(async(snapshot, context) => {
     const itemDataSnap = await snapshot.ref.get()
     console.log("Name of user requesting the ticket "+itemDataSnap.data().name):
 });