带有协程的 Firestore 快照?
Firestore Snapshot with Coroutines?
您好,我尝试制作 Coroutines Flow(使用 callbackFlow)并尝试将其转换为实时数据,但它似乎没有更新。
你可以在下面看到我的代码:
@ExperimentalCoroutinesApi
suspend fun checkInDanger(): Flow<NetworkStatus<List<UserFire>>> = callbackFlow {
val check = fs.collection(UserFire.COLLECTION).whereEqualTo(UserFire.DANGER, true)
.addSnapshotListener { value, e ->
if (e != null) {
trySend(NetworkStatus.Failed("Error occurred\n${e.code}"))
return@addSnapshotListener
}
if (value == null || value.isEmpty) trySend(NetworkStatus.Empty)
else {
val users = value.map { it.toObject(UserFire::class.java) }
trySend(NetworkStatus.Success(users))
}
}
awaitClose { }
}.flowOn(Dispatchers.IO)
在我的存储库中:
@ExperimentalCoroutinesApi
override suspend fun checkInDanger(): Flow<Status<List<User>>> = flow {
when (val result = network.checkInDanger().first()) {
is NetworkStatus.Success -> emit(Status.Success(result.data.map {
MapVal.userFireToDom(it)
}))
is NetworkStatus.Empty -> emit(Status.Success(listOf<User>()))
is NetworkStatus.Failed -> emit(Status.Error(null, result.error))
}
}
在我的 ViewModel 中:
val checkInDanger = liveData(Dispatchers.IO) {
try {
useCase.checkInDanger().collectLatest {
emit(it)
}
} catch (e: Exception) {
e.printStackTrace()
}
}
但是当我更改 Firebase 中的值时,它没有获取新数据...
任何人都知道为什么它没有修复
我找到了方法,但它有回调,如果我们使用回调,即使没有实时数据也可以获取数据更新,但对于我来说,我试图再次将回调推送到实时数据,
所以代码将是这样的:
fun checkInDanger(networkStatus: (NetworkStatus<List<UserFire>>) -> Unit) {
fs.collection(UserFire.COLLECTION).whereEqualTo(UserFire.DANGER, true)
.addSnapshotListener { value, e ->
if (e != null) {
networkStatus(NetworkStatus.Failed("Error occurred\n${e.code}"))
return@addSnapshotListener
}
if (value == null || value.isEmpty) networkStatus(NetworkStatus.Empty)
else {
val users = value.map { it.toObject(UserFire::class.java) }
networkStatus(NetworkStatus.Success(users))
}
}
}
在我的存储库中:
override fun checkInDanger(callback: (Status<List<User>>) -> Unit) {
network.checkInDanger { result ->
when (result) {
is NetworkStatus.Success -> callback(Status.Success(result.data.map {
MapVal.userFireToDom(it)
}))
is NetworkStatus.Empty -> callback(Status.Success(listOf<User>()))
is NetworkStatus.Failed -> callback(Status.Error(null, result.error))
}
}
}
在我的 ViewModel 中:
fun checkInDanger(callback: (Status<List<User>>) -> Unit) = useCase.checkInDanger { callback(it) }
val setUsers = MutableLiveData<List<User>>().apply { this.value = listOf() }
val users: LiveData<List<User>> = setUsers
在我的 UI Class(主要片段)中:
val inDangerCallback: (Status<List<User>>) -> Unit = {
if (relative != null) {
when (it) {
is Status.Success ->
viewModel.setUsers.value =
it.data?.filter { user -> user.username in relative!!.pure }
else -> requireView().createSnackBar(it.error!!, 1000)
}
}
}
viewModel.checkInDanger(inDangerCallback)
viewModel.users.observe(viewLifecycleOwner) { users ->
println(users.size})
users?.forEach { user -> println(user.username) }
}
并且代码可以运行完美并自动更新...
您好,我尝试制作 Coroutines Flow(使用 callbackFlow)并尝试将其转换为实时数据,但它似乎没有更新。
你可以在下面看到我的代码:
@ExperimentalCoroutinesApi
suspend fun checkInDanger(): Flow<NetworkStatus<List<UserFire>>> = callbackFlow {
val check = fs.collection(UserFire.COLLECTION).whereEqualTo(UserFire.DANGER, true)
.addSnapshotListener { value, e ->
if (e != null) {
trySend(NetworkStatus.Failed("Error occurred\n${e.code}"))
return@addSnapshotListener
}
if (value == null || value.isEmpty) trySend(NetworkStatus.Empty)
else {
val users = value.map { it.toObject(UserFire::class.java) }
trySend(NetworkStatus.Success(users))
}
}
awaitClose { }
}.flowOn(Dispatchers.IO)
在我的存储库中:
@ExperimentalCoroutinesApi
override suspend fun checkInDanger(): Flow<Status<List<User>>> = flow {
when (val result = network.checkInDanger().first()) {
is NetworkStatus.Success -> emit(Status.Success(result.data.map {
MapVal.userFireToDom(it)
}))
is NetworkStatus.Empty -> emit(Status.Success(listOf<User>()))
is NetworkStatus.Failed -> emit(Status.Error(null, result.error))
}
}
在我的 ViewModel 中:
val checkInDanger = liveData(Dispatchers.IO) {
try {
useCase.checkInDanger().collectLatest {
emit(it)
}
} catch (e: Exception) {
e.printStackTrace()
}
}
但是当我更改 Firebase 中的值时,它没有获取新数据... 任何人都知道为什么它没有修复
我找到了方法,但它有回调,如果我们使用回调,即使没有实时数据也可以获取数据更新,但对于我来说,我试图再次将回调推送到实时数据, 所以代码将是这样的:
fun checkInDanger(networkStatus: (NetworkStatus<List<UserFire>>) -> Unit) {
fs.collection(UserFire.COLLECTION).whereEqualTo(UserFire.DANGER, true)
.addSnapshotListener { value, e ->
if (e != null) {
networkStatus(NetworkStatus.Failed("Error occurred\n${e.code}"))
return@addSnapshotListener
}
if (value == null || value.isEmpty) networkStatus(NetworkStatus.Empty)
else {
val users = value.map { it.toObject(UserFire::class.java) }
networkStatus(NetworkStatus.Success(users))
}
}
}
在我的存储库中:
override fun checkInDanger(callback: (Status<List<User>>) -> Unit) {
network.checkInDanger { result ->
when (result) {
is NetworkStatus.Success -> callback(Status.Success(result.data.map {
MapVal.userFireToDom(it)
}))
is NetworkStatus.Empty -> callback(Status.Success(listOf<User>()))
is NetworkStatus.Failed -> callback(Status.Error(null, result.error))
}
}
}
在我的 ViewModel 中:
fun checkInDanger(callback: (Status<List<User>>) -> Unit) = useCase.checkInDanger { callback(it) }
val setUsers = MutableLiveData<List<User>>().apply { this.value = listOf() }
val users: LiveData<List<User>> = setUsers
在我的 UI Class(主要片段)中:
val inDangerCallback: (Status<List<User>>) -> Unit = {
if (relative != null) {
when (it) {
is Status.Success ->
viewModel.setUsers.value =
it.data?.filter { user -> user.username in relative!!.pure }
else -> requireView().createSnackBar(it.error!!, 1000)
}
}
}
viewModel.checkInDanger(inDangerCallback)
viewModel.users.observe(viewLifecycleOwner) { users ->
println(users.size})
users?.forEach { user -> println(user.username) }
}
并且代码可以运行完美并自动更新...