Did anyone implement google autocomplete suggestion text field or fragment in a jetpack compose project? If so kindly guide or share code snippets as I'm having difficulty in implementing it.
Update
Here is the intent that I'm triggering to open full-screen dialog, but when I start typing within it gets closed, and also I'm unable to figure out what the issue is and need a clue about handling on activity result for reading the result of the predictions within this compose function.
Places.initialize(context, "sa")
val fields = listOf(Place.Field.ID, Place.Field.NAME)
val intent = Autocomplete.IntentBuilder(
AutocompleteActivityMode.FULLSCREEN,fields).build(context)
startActivityForResult(context as MainActivity,intent, AUTOCOMPLETE_REQUEST_CODE, Bundle.EMPTY)
I am using the MVVM architecture and this is how I implemented it:
GooglePlacesApi
I've created an api for reaching google api named GooglePlacesApi
interface GooglePlacesApi {
#GET("maps/api/place/autocomplete/json")
suspend fun getPredictions(
#Query("key") key: String = <GOOGLE_API_KEY>,
#Query("types") types: String = "address",
#Query("input") input: String
): GooglePredictionsResponse
companion object{
const val BASE_URL = "https://maps.googleapis.com/"
}
}
The #Query("types") field is for specifiying what are you looking for in the query, you can look for establishments etc.
Types can be found here
Models
So I created 3 models for this implementation:
GooglePredictionsResponse
The way the response looks if you are doing a GET request with postman is:
Google Prediction Response
You can see that we have an object with "predictions" key so this is our first model.
data class GooglePredictionsResponse(
val predictions: ArrayList<GooglePrediction>
)
GooglePredictionTerm
data class GooglePredictionTerm(
val offset: Int,
val value: String
)
GooglePrediction
data class GooglePrediction(
val description: String,
val terms: List<GooglePredictionTerm>
)
I only needed that information, if you need anything else, feel free to modify the models or create your own.
GooglePlacesRepository
And finally we create the repository to get the information (I'm using hilt to inject my dependencies, you can ignore those annotations if not using it)
#ActivityScoped
class GooglePlacesRepository #Inject constructor(
private val api: GooglePlacesApi,
){
suspend fun getPredictions(input: String): Resource<GooglePredictionsResponse>{
val response = try {
api.getPredictions(input = input)
} catch (e: Exception) {
Log.d("Rently", "Exception: ${e}")
return Resource.Error("Failed prediction")
}
return Resource.Success(response)
}
}
Here I've used an extra class I've created to handle the response, called Resource
sealed class Resource<T>(val data: T? = null, val message: String? = null){
class Success<T>(data: T): Resource<T>(data)
class Error<T>(message: String, data:T? = null): Resource<T>(data = data, message = message)
class Loading<T>(data: T? = null): Resource<T>(data = data)
}
View Model
Again I'm using hilt so ignore annotations if not using it.
#HiltViewModel
class AddApartmentViewModel #Inject constructor(private val googleRepository: GooglePlacesRepository): ViewModel(){
val isLoading = mutableStateOf(false)
val predictions = mutableStateOf(ArrayList<GooglePrediction>())
fun getPredictions(address: String) {
viewModelScope.launch {
isLoading.value = true
val response = googleRepository.getPredictions(input = address)
when(response){
is Resource.Success -> {
predictions.value = response.data?.predictions!!
}
}
isLoading.value = false
}
}
fun onSearchAddressChange(address: String){
getPredictions(address)
}
}
If you need any further help let me know
I didn't include UI implementation because I assume it is individual but this is the easier part ;)
#Composable
fun MyComponent() {
val context = LocalContext.current
val intentLauncher = rememberLauncherForActivityResult(
contract = ActivityResultContracts.StartActivityForResult()
) {
when (it.resultCode) {
Activity.RESULT_OK -> {
it.data?.let {
val place = Autocomplete.getPlaceFromIntent(it)
Log.i("MAP_ACTIVITY", "Place: ${place.name}, ${place.id}")
}
}
AutocompleteActivity.RESULT_ERROR -> {
it.data?.let {
val status = Autocomplete.getStatusFromIntent(it)
Log.i("MAP_ACTIVITY", "Place: ${place.name}, ${place.id}")
}
}
Activity.RESULT_CANCELED -> {
// The user canceled the operation.
}
}
}
val launchMapInputOverlay = {
Places.initialize(context, YOUR_API_KEY)
val fields = listOf(Place.Field.ID, Place.Field.NAME)
val intent = Autocomplete
.IntentBuilder(AutocompleteActivityMode.OVERLAY, fields)
.build(context)
intentLauncher.launch(intent)
}
Column {
Button(onClick = launchMapInputOverlay) {
Text("Select Location")
}
}
}
Related
I have the following setup.
I have a screen with a list of items (PlantsScreen). When clicking on an item from the list I will be navigated to another screen (AddEditPlantScreen). After editing and saving the item and navigating back to the listScreen, I want to show the updated list of items. But the list is not displaying the updated list but the list before the edit of the item.
In order to have a single source of truth, I am fetching the data from a node.js Back-End and then saving it to the local repository (Room). I think I need to refresh the state in the ViewModel to fetch the updated list from my repository.
I know I can use a Job to do this, but it throws me an error. Is this the correct approach when returning a Flow?
If yes, how can I achieve this.
If not, what alternative approach do I have?
plantsListViewModel.kt
private val _state = mutableStateOf<PlantsState>(PlantsState())
val state: State<PlantsState> = _state
init {
getPlants(true, "")
}
private fun getPlants(fetchFromBackend: Boolean, query: String) {
viewModelScope.launch {
plantRepository.getPlants(fetchFromBackend, query)
.collect { result ->
when (result) {
is Resource.Success -> {
result.data?.let { plants ->
_state.value = state.value.copy(
plants = plants,
)
}
}
}
}
}
}
Here is my repository where I fetch the items in the list from.
// plantsRepository.kt
override suspend fun getPlants(
fetchFromBackend: Boolean,
query: String
): Flow<Resource<List<Plant>>> {
return flow {
emit(Resource.Loading(true))
val localPlants = dao.searchPlants(query)
emit(
Resource.Success(
data = localPlants.map { it.toPlant() },
)
)
val isDbEmpty = localPlants.isEmpty() && query.isBlank()
val shouldLoadFromCache = !isDbEmpty && !fetchFromBackend
if (shouldLoadFromCache) {
emit(Resource.Loading(false))
return#flow
}
val response = plantApi.getPlants().plants
dao.clearPlants()
dao.insertPlants(
response.map { it.toPlantEntity() }
)
emit(Resource.Success(
data = dao.searchPlants("").map { it.toPlant() }
))
emit(Resource.Loading(false))
}
}
The full code for reference can be found here:
https://gitlab.com/fiehra/plants
Thank you!
You actually have two sources of truth: One is the room database, the other the _state object in the view model.
To reduce this to a single source of truth you need to move the collection of the flow to the compose function where the data is needed. You will do this using the extension function StateFlow.collectAsStateWithLifecycle() from the artifact androidx.lifecycle:lifecycle-runtime-compose. This will automatically subscribe and unsubscribe the flow when your composable enters and leaves the composition.
Since you want the business logic to stay in the view model you have to apply it before the flow is collected. The idea is to only transform the flow in the view model:
class PlantsViewModel {
private var fetchFromBackend: Boolean by mutableStateOf(true)
private var query: String by mutableStateOf("")
#OptIn(ExperimentalCoroutinesApi::class)
val state: StateFlow<PlantsState> =
snapshotFlow { fetchFromBackend to query }
.flatMapLatest { plantRepository.getPlants(it.first, it.second) }
.mapLatest(PlantsState::of)
.stateIn(
scope = viewModelScope,
started = SharingStarted.WhileSubscribed(5_000),
initialValue = PlantsState.Loading,
)
// ...
}
If you want other values for fetchFromBackend and query you just need to update the variables; the flow will automatically recalculate the state object. It can be as simple as just calling something like this:
fun requestPlant(fetchFromBackend: Boolean, query: String) {
this.fetchFromBackend = fetchFromBackend
this.query = query
}
The logic to create a PlantsState from a result can then be done somewhere else in the view model. Replace your PlantsViewModel.getPlants() with this and place it at file level outside of the PlantsViewModel class:
private fun PlantsState.Companion.of(result: Resource<List<Plant>>): PlantsState = when (result) {
is Resource.Success -> {
result.data?.let { plants ->
PlantsState.Success(
plants = plants,
)
} ?: TODO("handle case where result.data is null")
}
is Resource.Error -> {
PlantsState.Error("an error occurred")
}
is Resource.Loading -> {
PlantsState.Loading
}
}
With the PlantsState class replaced by this:
sealed interface PlantsState {
object Loading : PlantsState
data class Success(
val plants: List<Plant> = emptyList(),
val plantOrder: PlantOrder = PlantOrder.Name(OrderType.Descending),
val isOrderSectionVisible: Boolean = false,
) : PlantsState
data class Error(
val error: String,
) : PlantsState
companion object
}
Then, wherever you need the state (in PlantsScreen f.e.), you can get a state object with
val state by viewModel.state.collectAsStateWithLifecycle()
Thanks to kotlin flows state will always contain the most current data from the room database, and thanks to the compose magic your composables will always update when anything in the state object updates, so that you really only have one single source of truth.
Additionally:
PlantRepository.getPlants() should not be marked as a suspend function because it just creates a flow and won't block; long running data retrieval will be done in the collector.
You will need to manually import androidx.compose.runtime.getValue and the androidx.compose.runtime.setValue for some of the delegates to work.
After #Leviathan was able to point me in the right direction i refactored my code by changing the return types of my repository functions, implementing use cases and returning a Flow<List<Plant>> instead of Flow<Resource<List<Plant>>> for simplicity purposes.
Further removed the suspend marker of the functions in the PlantDao.kt and PlantRepository.kt as pointed out by Leviathan.
// PlantRepositoryImplementation.kt
override fun getPlants(
fetchFromBackend: Boolean,
query: String
): Flow<List<Plant>> {
return flow {
if (fetchFromBackend) {
val response = plantApi.getPlants().plants
dao.clearPlants()
dao.insertPlants(
response.map { it.toPlantEntity() }
)
val localPlants = dao.searchPlants(query)
localPlants.collect { plants ->
emit(plants.map { it.toPlant() })
return#collect
}
} else {
val localPlants = dao.searchPlants(query)
localPlants.collect { plants ->
emit(plants.map { it.toPlant() })
return#collect
}
}
}
}
I started using a Job and GetPlants usecase in my viewModel like this:
// PlantsViewModel.kt
private fun getPlants(plantOrder: PlantOrder, fetchFromBackend: Boolean, query: String) {
getPlantsJob?.cancel()
getPlantsJob = plantUseCases.getPlants(plantOrder, fetchFromBackend, query)
.onEach { plants ->
_state.value = state.value.copy(
plants = plants,
plantOrder = plantOrder
)
}.launchIn(viewModelScope)
I also had to remove the suspend in the PlantDao.kt
// PlantDao.kt
fun searchPlants(query: String): Flow<List<PlantEntity>>
This is the code for my GetPlants usecase:
// GetPlantsUsecase.kt
class GetPlants
(
private val repository: PlantRepository,
) {
operator fun invoke(
plantOrder: PlantOrder = PlantOrder.Name(OrderType.Descending),
fetchFromBackend: Boolean,
query: String
): Flow<List<Plant>> {
return repository.getPlants(fetchFromBackend, query).map { plants ->
when (plantOrder.orderType) {
is OrderType.Ascending -> {
// logic for sorting
}
}
is OrderType.Descending -> {
// logic for sorting
}
}
}
}
}
I want to implement search functionality among lists of banks in my app.
So somehow I need to use stringResId() but you can't call it without composable func(). Also by using Resources.getSystem().getString() is giving me resources not found exception.
This is my viewModel code
class BankViewModel: ViewModel() {
private val _bankAccount = MutableStateFlow(BankAccount())
val bankAccount: StateFlow<BankAccount> = _bankAccount.asStateFlow()
var bankList = mutableStateOf(Banks)
private var cachedBankList = listOf<Bank>()
private var isSearchStarting = true
var isSearching = mutableStateOf(false)
fun updateBankSearch(searchName: String) {
_bankAccount.update { bankAccount ->
bankAccount.copy(bankName = searchName)
}
}
fun searchBankName(query: String) {
val listToSearch = if(isSearchStarting) {
bankList.value
}else {
cachedBankList
}
viewModelScope.launch {
if (query.isEmpty()) {
bankList.value = cachedBankList
isSearching.value = false
isSearchStarting = true
return#launch
}
val results = listToSearch.filter {
Resources.getSystem().getString(it.bankName).contains(query.trim(), ignoreCase = true)
}
if (isSearchStarting) {
cachedBankList = bankList.value
isSearchStarting = false
}
bankList.value = results
isSearching.value = true
}
}
}
This is my Bank
data class Bank (
#StringRes val bankName: Int,
#DrawableRes val bankLogo: Int = R.drawable.bank_image_2
)
So my question is how can I get a string by using id so that I can compare it with the query??
You need to use the Application Context to retrieve resources like these.
If you're not using any DI framework, or you don't want to use custom ViewModelProvider.Factory, extend AndroidViewModel (which holds a reference to Application) instead of regular ViewModel.
Ideally ViewModels shouldn't contain any Android-specific objects, and you would use some custom StringProvider, or something similar, but that's not a topic of your question.
I'm a junior Android developer and trying to build a Facebook-like social media app. My issue is that when I bookmark a post in Screen B and the action succeeds, (1) I want to launch an API request in Screen A while in Screen B and (2) update the bookmarked icon ONLY for that particular post.
For the second part of the issue, I tried these two solutions.
I relaunched a manual API request on navigating back to Screen A. This updates the whole list when there's only one small change, hence very inefficient.
I built another URL route to fetch that updated post only and launched it on navigating back to Screen A. But to insert the newly updated post at the old index, the list has to be mutable and I ain't sure this is a good practice.
Please help me on how to solve this issue or similar issues. I'm not sure if this should be done by passing NavArg to update locally and then some or by using web sockets. Thanks in advance.
data class ScreenAState(
val posts: List<Post> = emptyList(),
val isLoading: Boolean = false)
data class ScreenBState(
val post: PostDetail? = null,
val isBookmarked: Boolean? = null)
data class Post(
val title: String,
val isBookMarked: Boolean,
val imageUrl: String)
data class PostDetail(
val title: String,
val content: String,
val isBookMarked: Boolean,
val imageUrl: String)
I suggest you continue with using your logic that will update your list on return from screen B to screen A, but instead of using simple list, you could use:
https://developer.android.com/reference/kotlin/androidx/compose/runtime/snapshots/SnapshotStateList
This list is designed for what you need I think. Update just that one element.
In mean time, you can change that item from list to some loading dummy item, if you want to have loading like view while you wait for API call to finish.
The problem is how to handle data consistency, which is not directly related to jetpack compose. I suggest you solve this problem at the model level. Return flow instead of static data in the repository, and use collectAsState in the jetpack compose to monitor data changes.
It's hard to give an example, because it depends on the type of Model layer. If it's a database, androidx's room library supports returning flow; if it's a network, take a look at this.
https://gist.github.com/FishHawk/6e4706646401bea20242bdfad5d86a9e
Triggering a refresh is not a good option. It is better to maintain an ActionChannel in the repository for each list that is monitored. use the ActionChannel to modify the list locally to notify compose of the update.
For example, you can make a PagedList if the data layer is network. With onStart and onClose, channels can be added or removed from the repository, thus giving the repository the ability to update all the observed lists.
sealed interface RemoteListAction<out T> {
data class Mutate<T>(val transformer: (MutableList<T>) -> MutableList<T>) : RemoteListAction<T>
object Reload : RemoteListAction<Nothing>
object RequestNextPage : RemoteListAction<Nothing>
}
typealias RemoteListActionChannel<T> = Channel<RemoteListAction<T>>
suspend fun <T> RemoteListActionChannel<T>.mutate(transformer: (MutableList<T>) -> MutableList<T>) {
send(RemoteListAction.Mutate(transformer))
}
suspend fun <T> RemoteListActionChannel<T>.reload() {
send(RemoteListAction.Reload)
}
suspend fun <T> RemoteListActionChannel<T>.requestNextPage() {
send(RemoteListAction.RequestNextPage)
}
class RemoteList<T>(
private val actionChannel: RemoteListActionChannel<T>,
val value: Result<PagedList<T>>?,
) {
suspend fun mutate(transformer: (MutableList<T>) -> MutableList<T>) =
actionChannel.mutate(transformer)
suspend fun reload() = actionChannel.reload()
suspend fun requestNextPage() = actionChannel.requestNextPage()
}
data class PagedList<T>(
val list: List<T>,
val appendState: Result<Unit>?,
)
data class Page<Key : Any, T>(
val data: List<T>,
val nextKey: Key?,
)
fun <Key : Any, T> remotePagingList(
startKey: Key,
loader: suspend (Key) -> Result<Page<Key, T>>,
onStart: ((actionChannel: RemoteListActionChannel<T>) -> Unit)? = null,
onClose: ((actionChannel: RemoteListActionChannel<T>) -> Unit)? = null,
): Flow<RemoteList<T>> = callbackFlow {
val dispatcher = Dispatchers.IO.limitedParallelism(1)
val actionChannel = Channel<RemoteListAction<T>>()
var listState: Result<Unit>? = null
var appendState: Result<Unit>? = null
var value: MutableList<T> = mutableListOf()
var nextKey: Key? = startKey
onStart?.invoke(actionChannel)
suspend fun mySend() {
send(
RemoteList(
actionChannel = actionChannel,
value = listState?.map {
PagedList(
appendState = appendState,
list = value,
)
},
)
)
}
fun requestNextPage() = launch(dispatcher) {
nextKey?.let { key ->
appendState = null
mySend()
loader(key)
.onSuccess {
value.addAll(it.data)
nextKey = it.nextKey
listState = Result.success(Unit)
appendState = Result.success(Unit)
mySend()
}
.onFailure {
if (listState?.isSuccess != true)
listState = Result.failure(it)
appendState = Result.failure(it)
mySend()
}
}
}
var job = requestNextPage()
launch(dispatcher) {
actionChannel.receiveAsFlow().flowOn(dispatcher).collect { action ->
when (action) {
is RemoteListAction.Mutate -> {
value = action.transformer(value)
mySend()
}
is RemoteListAction.Reload -> {
job.cancel()
listState = null
appendState = null
value.clear()
nextKey = startKey
mySend()
job = requestNextPage()
}
is RemoteListAction.RequestNextPage -> {
if (!job.isActive) job = requestNextPage()
}
}
}
}
launch(dispatcher) {
Connectivity.instance?.interfaceName?.collect {
if (job.isActive) {
job.cancel()
job = requestNextPage()
}
}
}
awaitClose {
onClose?.invoke(actionChannel)
}
}
And in repository:
val postListActionChannels = mutableListOf<RemoteListActionChannel<Post>>()
suspend fun listPost() =
daoFlow.filterNotNull().flatMapLatest {
remotePagingList(
startKey = 0,
loader = { page ->
it.mapCatching { dao ->
/* dao function, simulate network operation, return List<Post> */
dao.listPost(page)
}.map { Page(it, if (it.isEmpty()) null else page + 1) }
},
onStart = { postListActionChannels.add(it) },
onClose = { postListActionChannels.remove(it) },
)
}
suspend fun markPost(title: String) =
oneshot {
/* dao function, simulate network operation, return Unit */
it.markPost(title)
}.onSuccess {
postListActionChannels.forEach { ch ->
ch.mutate { list ->
list.map {
if (it.title == title && !it.isBookMarked)
it.copy(isBookMarked = true)
else it
}.toMutableList()
}
}
}
I used this CodeLabs tutorial to learn how to make an HTTP request from the Google Books API
https://codelabs.developers.google.com/codelabs/kotlin-android-training-internet-data/#4
Right now, I'm trying to access a nested JSON object that the Google Books API spits out
I.e
"items": [{
"kind": "books#volume",
"id": "mOsbHQAACAAJ",
"volumeInfo" : {
"description": "Young wizard Harry Potter finds himself back at the miserable Hogwarts School of Witchcraft and Wizardry. He doesn't realize the difficulty of the task that awaits him. Harry must pull out all the stops in order to find his missing friend. No Canadian Rights for the Harry Potter Series HARRY POTTER and all related characters and elements are trademarks of and (c) Warner Bros. Entertainment Inc. Harry Potter publishing rights (c) J. K. Rowling. (s05)",
"imageLinks": {
"smallThumbnail": "http://books.google.com/books/content?id=mOsbHQAACAAJ&printsec=frontcover&img=1&zoom=5&source=gbs_api",
"thumbnail": "http://books.google.com/books/content?id=mOsbHQAACAAJ&printsec=frontcover&img=1&zoom=1&source=gbs_api"
}
},
I just want the description and thumbnail property.
My interface for the API service is
package com.example.customapp.network
import com.squareup.moshi.Moshi
import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
import retrofit2.Call
import retrofit2.Retrofit
import retrofit2.converter.moshi.MoshiConverterFactory
import retrofit2.http.GET
//Code from https://codelabs.developers.google.com/codelabs/kotlin-android-training-internet-data/#3
private const val BASE_URL = "https://www.googleapis.com/books/v1/"
private val moshi = Moshi.Builder()
.add(KotlinJsonAdapterFactory())
.build()
private val retrofit = Retrofit.Builder()
.addConverterFactory(MoshiConverterFactory.create(moshi))
.baseUrl(BASE_URL)
.build()
interface BookApiService {
//Get annotation specifies the endpoint for this web service method.
//when getProperties() method is invoked, Retrofit appends the endpoint 'book' to the base URL
//And creates a Call object. The Call object is used to start the request.
#GET("volumes?q='harry+potter")
suspend fun getProperties(): BookProperty
}
object BookApi {
val retrofitService: BookApiService by lazy {
retrofit.create(BookApiService::class.java)
}
}
}
My BookProperty.kt is
data class BookProperty(#field:Json(name = "items" ) val bookDetail: List<BookDetail>)
data class BookDetail(#field:Json(name = "volumeInfo") val volumeInfo: VolumeInfo)
data class VolumeInfo(#field:Json(name = "description") val description: String, #field:Json(name= "imageLinks") val imageLink: ImageLink)
data class ImageLink(#field:Json(name = "thumbnail") val thumbnail: String)
I'm calling the API from my ViewModel
val readAllData: LiveData<List<BookItem>>
private val repository: BookRepository
private val _response = MutableLiveData<String>()
val response: LiveData<String>
get() = _response
init {
val bookDao = BookDatabase.getDatabase(application).bookDao()
repository = BookRepository(bookDao)
readAllData = repository.readAllData
}
fun addBook(book: BookItem) {
viewModelScope.launch(Dispatchers.IO) {
repository.addBook(book)
}
}
fun updateBook(book: BookItem) {
viewModelScope.launch(Dispatchers.IO) {
repository.updateBook(book)
}
}
fun getBookDetailProperties() {
viewModelScope.launch {
try {
//calling get properties from the BookApi service creates and starts the network call
//on a background thread
var listResult = BookApi.retrofitService.getProperties()
_response.value = "${
listResult.bookDetail[0].volumeInfo.description} book properties received"
} catch (e: Exception) {
_response.value = "Failure: ${e.message}"
}
}
}
I'm trying to make an HTTP request each time I update an item on my CRUD app i.e when I click a button, but I can't seem to get any response back. This is my UpdateFragment where I initiate the API call.
class UpdateFragment : Fragment() {
//Read up on delegation
//https://codelabs.developers.google.com/codelabs/kotlin-bootcamp-classes/#7
//UpdateFragmentArgs is a class that is automatically generated
//when we created an argument for our Update Fragment in the nav graph
//UpdateFragmentArgs will contain our current book
//we can also use bundle
private val args by navArgs<UpdateFragmentArgs>()
private lateinit var mBookViewModel: BookViewModel
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
val view = inflater.inflate(R.layout.fragment_update, container, false)
//So the keyboard doesn't push the EditText fields up
this.activity?.window?.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN)
Glide
.with(this)
.load(args.currentBook.image)
.into(view.bookImageDetail)
mBookViewModel = ViewModelProvider(this).get(BookViewModel::class.java)
view.apply {
updateInputName.setText(args.currentBook.title)
updateInputAuthor.setText(args.currentBook.author)
updateBookDesc.text = args.currentBook.desc
updateRatingBar.rating = args.currentBook.rating.toFloat()
updateBookCompleted.isChecked = args.currentBook.finished
updateBookCompleted.text =
if (updateBookCompleted.isChecked) getString(R.string.book_completed) else getString(
R.string.book_not_completed
)
updateDateCreated.text = getString(R.string.date_created, args.currentBook.dateCreated)
}
view.updateBtn.setOnClickListener {
updateItem()
}
view.updateBookCompleted.setOnCheckedChangeListener { _, isChecked ->
if (isChecked) {
view.updateBookCompleted.text = getString(R.string.book_completed)
} else {
view.updateBookCompleted.text = getString(R.string.book_not_completed)
}
}
return view
}
private fun updateItem() {
val bookName = updateInputName.text.toString()
val bookAuthor = updateInputAuthor.text.toString()
val bookRating = updateRatingBar.rating.toDouble()
val bookFinished = updateBookCompleted.isChecked
if (inputCheck(bookName, bookAuthor)) {
//***Initiate API call here ****
mBookViewModel.getBookDetailProperties()
//Get description and image from API
mBookViewModel.response.observe(viewLifecycleOwner, {
println("Get resp " + it)
})
//Create book object
val updatedBook = BookItem(
args.currentBook.id,
bookName,
bookAuthor,
args.currentBook.desc,
args.currentBook.image,
bookRating,
args.currentBook.dateCreated,
bookFinished
)
//update current book
mBookViewModel.updateBook(updatedBook)
Toast.makeText(requireContext(), "Updated book successfully!", Toast.LENGTH_SHORT)
.show()
//navigate back
findNavController().navigate(R.id.action_updateFragment_to_listFragment)
}
}
private fun inputCheck(bookName: String, authorName: String): Boolean {
return !(TextUtils.isEmpty(bookName) && TextUtils.isEmpty(authorName))
}
}
The issue is I can't get any response from the API call - I'm not sure if it's because of the nested objects in the JSON. Please help me shed some light on this, I'm still new to Kotlin programming.
I found out the reason why I was not getting any response.
In my UpdateFragment, I'm doing this:
//Get description and image from API
mBookViewModel.response.observe(viewLifecycleOwner, {
println("Get resp " + it)
})
//Create book object
val updatedBook = BookItem(
args.currentBook.id,
bookName,
bookAuthor,
args.currentBook.desc,
args.currentBook.image,
bookRating,
args.currentBook.dateCreated,
bookFinished
)
//update current book
mBookViewModel.updateBook(updatedBook)
Toast.makeText(requireContext(), "Updated book successfully!", Toast.LENGTH_SHORT)
.show()
//navigate back
findNavController().navigate(R.id.action_updateFragment_to_listFragment)
I am navigating back to another fragment before I can observe any changes from the HTTP response. This causes the observer to stop observing any changes, and thus I can't get a response. I just need to put my code inside the callback, so I can do something with the data I received. Like so:
//Get description and image from API
mBookViewModel.response.observe(viewLifecycleOwner, {
println("Get resp " + it)
//Create book object
val updatedBook = BookItem(
args.currentBook.id,
bookName,
bookAuthor,
args.currentBook.desc,
args.currentBook.image,
bookRating,
args.currentBook.dateCreated,
bookFinished
)
//update current book
mBookViewModel.updateBook(updatedBook)
Toast.makeText(requireContext(), "Updated book successfully!", Toast.LENGTH_SHORT)
.show()
//navigate back
findNavController().navigate(R.id.action_updateFragment_to_listFragment)
})
Hopefully this helps out anyone who has just started out learning LiveData and using HTTP requests.
I'm new to kotlin so this maybe a very easy issue to resolve.
What I'm trying to do is filter the json response that I receive using Retrofit2 before I display the images in a grid with a RecyclerView.
instagram.com/explore/tags/{hashtag}/?__a=1&max_id= Using Retrofit2 I'm able to get the data response fine and also display the given url images in a RecyclerView.
I have not been successful in using the filter, map, loops and conditions to remove elements from the Arraylist. I do not understand these to the fullest extent but I have searched looking for solutions and those are what I came apon.
Interface
interface InstagramDataFetcher
{
#GET("tags/{tag}/?__a=1&max_id=")
fun getInstagramData(#Path("tag") hashtag: String) : Call <InstagramResponse>
}
Where I get my response from and also get StringIndexOutOfBoundsException
class InstagramFeedFragment : Fragment()
{
private fun onResponse()
{
val service = RestAPI.retrofitInstance?.create(InstagramDataFetcher::class.java)
val call = service?.getInstagramData("hashtag")
call?.enqueue(object : Callback<InstagramResponse>
{
override fun onFailure(call: Call<InstagramResponse>, t: Throwable)
{
Log.d("FEED", " $t")
}
override fun onResponse(
call: Call<InstagramResponse>, response: Response<InstagramResponse>
)
{
//for ((index, value) in data.withIndex())
if (response.isSuccessful)
{
var data: ArrayList<InstagramResponse.InstagramEdgesResponse>? = null
val body = response.body()
data = body!!.graphql.hashtag.edge_hashtag_to_media.edges
for ((index, value) in data.withIndex())
{
if(value.node.accessibility_caption[index].toString().contains("text") ||
value.node.accessibility_caption[index].toString().contains("person"))
{
data.drop(index)
}
}
recyclerView.adapter = InstagramGridAdapter(data, parentFragment!!.context!!)
}
}
})
}
}
This is my model class
data class InstagramResponse(val graphql: InstagramGraphqlResponse)
{
data class InstagramGraphqlResponse(val hashtag: InstagramHashtagResponse)
data class InstagramHashtagResponse(val edge_hashtag_to_media: InstagramHashtagToMediaResponse)
data class InstagramHashtagToMediaResponse(
val page_info: InstagramPageInfo,
val edges: ArrayList<InstagramEdgesResponse>
)
data class InstagramPageInfo(
val has_next_page: Boolean,
val end_cursor: String
)
data class InstagramEdgesResponse(val node: InstagramNodeResponse)
data class InstagramNodeResponse(
val __typename: String,
val shortcode: String,
val display_url: String,
val thumbnail_src: String,
val thumbnail_resources: ArrayList<InstagramThumbnailResourceResponse>,
val is_video: Boolean,
val accessibility_caption: String
)
data class InstagramThumbnailResourceResponse(
val src: String,
val config_width: Int,
val config_height: Int
)
}
Simply again, I want to just remove elements from the arraylist that match certain things what I don't want. For instance. the "is_video" value that comes from the json. I want to go through the arraylist and remove all elements that have "is_video" as true.
Thanks
If you asking how to filter the list then below is the demo.
You just need to use filter on your data which is an ArrayList. I've tried keeping the same structure for the models so that you can get a better understanding.
fun main() {
val first = InstagramNodeResponse(
title = "first",
is_video = true
)
val second = InstagramNodeResponse(
title = "second",
is_video = false
)
val list: ArrayList<InstagramEdgesResponse> = arrayListOf(
InstagramEdgesResponse(node = first),
InstagramEdgesResponse(node = second)
)
val itemsWithVideo = list.filter { it.node.is_video == true }
val itemsWithoutVideo = list.filter { it.node.is_video == false }
println(itemsWithVideo.map { it.node.title }) // [first]
println(itemsWithoutVideo.map { it.node.title }) // [second]
}
// Models
data class InstagramEdgesResponse(val node: InstagramNodeResponse)
data class InstagramNodeResponse(
val title: String,
val is_video: Boolean
)