I am developing a news app and I have implemented ViewModel in fragment class and getting data in fragment class but it is loading progress bar only not showing data which coming from server
below My MainViewModel.kt
class MainViewModel(newsRepository: Any?) : ViewModel(), CoroutineScope {
// Coroutine's background job
val job = Job()
val sportNewsInterface: SportNewsInterface? = null
// Define default thread for Coroutine as Main and add job
override val coroutineContext: CoroutineContext = Dispatchers.Main + job
val showLoading = MutableLiveData<Boolean>()
val sportList = MutableLiveData <List<Article>>()
val showError = SingleLiveEvent<String>()
fun loadNews(
) {
// Show progressBar during the operation on the MAIN (default) thread
showLoading.value = true
// launch the Coroutine
launch {
// Switching from MAIN to IO thread for API operation
// Update our data list with the new one from API
val result = withContext(Dispatchers.IO) {
sportNewsInterface?.getNews()
}
// Hide progressBar once the operation is done on the MAIN (default) thread
showLoading.value = false
when (result) {
is UseCaseResult.Success<*> -> {
sportList.value = result.data as List<Article>
}
is Error -> showError.value = result.message
}
}
}
override fun onCleared() {
super.onCleared()
// Clear our job when the linked activity is destroyed to avoid memory leaks
job.cancel()
}
}
below Adapter class
class TopHeadlinesAdapter(val context: Context) :
RecyclerView.Adapter<TopHeadlinesAdapter.MyViewHolder>() {
private var articleList: List<Article> by Delegates.observable(emptyList()) { _, _, _ ->
notifyDataSetChanged()
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
val view = LayoutInflater.from(parent.context).inflate(R.layout.news_list, parent, false)
return MyViewHolder(view)
}
override fun getItemCount(): Int {
return articleList.size
}
@SuppressLint("NewApi")
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.articleTitle.text = articleList.get(position).title
holder.articleSourceName.text = articleList.get(position).source.name
Picasso.get().load(articleList.get(position).urlToImage).into(holder.image)
val input = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX")
val output = SimpleDateFormat("dd/MM/yyyy")
var d = Date()
try {
d = input.parse(articleList[5].publishedAt)
} catch (e: ParseException) {
try {
val fallback = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'")
fallback.timeZone = TimeZone.getTimeZone("UTC")
d = fallback.parse(articleList[5].publishedAt)
} catch (e2: ParseException) {
// TODO handle error
val formatted = output.format(d)
val timelinePoint = LocalDateTime.parse(formatted)
val now = LocalDateTime.now()
var elapsedTime = Duration.between(timelinePoint, now)
println(timelinePoint)
println(now)
elapsedTime.toMinutes()
holder.articleTime.text = "${elapsedTime.toMinutes()}"
}
}
}
fun updateData(newList: List<Article>) {
articleList = newList
}
@SuppressLint("NewApi")
fun example() {
}
class MyViewHolder(itemView: View?) : RecyclerView.ViewHolder(itemView!!) {
val image: ImageView = itemView!!.findViewById(R.id.imageView)
val articleTitle: TextView = itemView!!.findViewById(R.id.articleTitle)
val articleSourceName: TextView = itemView!!.findViewById(R.id.articleSourceName)
val imageCategory: ImageView = itemView!!.findViewById(R.id.imageCategory)
val articleTime: TextView = itemView!!.findViewById(R.id.articleTime)
}
}
below TopHeadlinesFragment where I have implemented ViewModel
class TopHeadlinesFragment : Fragment() {
private var viewModel: MainViewModel? = null
private lateinit var topHeadlinesAdapter: TopHeadlinesAdapter
//3
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(
R.layout.fragment_top_headlines
, container, false
)
val recyclerView = view.findViewById(R.id.recyclerView) as RecyclerView
val pb = view.findViewById(R.id.pb) as ProgressBar
topHeadlinesAdapter = TopHeadlinesAdapter(recyclerView.context)
recyclerView.layoutManager = LinearLayoutManager(context)
recyclerView.adapter = topHeadlinesAdapter
initViewModel()
return view
}
private fun initViewModel() {
viewModel?.sportList?.observe(this, Observer { newList ->
topHeadlinesAdapter.updateData(newList)
})
viewModel?.showLoading?.observe(this, Observer { showLoading ->
pb.visibility = if (showLoading) View.VISIBLE else View.GONE
viewModel?.showError?.observe(this, Observer { showError ->
(showError)
})
viewModel?.loadNews()
})
}
}
below AppModules.kt
const val BASE_URL = "https://newsapi.org/"
val appModules = module {
// The Retrofit service using our custom HTTP client instance as a singleton
single {
createWebService<SportNewsInterface>(
okHttpClient = createHttpClient(),
factory = RxJava2CallAdapterFactory.create(),
baseUrl = BASE_URL
)
}
// Tells Koin how to create an instance of CatRepository
factory<NewsRepository> { (NewsRepositoryImpl(sportNewsInterface = get())) }
// Specific viewModel pattern to tell Koin how to build MainViewModel
viewModel { MainViewModel (newsRepository = get ()) }
}
/* Returns a custom OkHttpClient instance with interceptor. Used for building Retrofit service */
fun createHttpClient(): OkHttpClient {
val client = OkHttpClient.Builder()
client.readTimeout(5 * 60, TimeUnit.SECONDS)
return client.addInterceptor {
val original = it.request()
val requestBuilder = original.newBuilder()
requestBuilder.header("Content-Type", "application/json")
val request = requestBuilder.method(original.method, original.body).build()
return@addInterceptor it.proceed(request)
}.build()
}
/* function to build our Retrofit service */
inline fun <reified T> createWebService(
okHttpClient: OkHttpClient,
factory: CallAdapter.Factory, baseUrl: String
): T {
val retrofit = Retrofit.Builder()
.baseUrl(baseUrl)
.addConverterFactory(GsonConverterFactory.create(GsonBuilder().setLenient().create()))
.addCallAdapterFactory(CoroutineCallAdapterFactory())
.addCallAdapterFactory(factory)
.client(okHttpClient)
.build()
return retrofit.create(T::class.java)
}
below fragment_top_headlines.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ProgressBar
android:id="@+id/pb"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
below news_list.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:layout_marginBottom="16dp">
<ImageView
android:id="@+id/imageView"
android:layout_width="100dp"
android:layout_height="85dp"
android:layout_marginStart="16dp"
android:layout_marginLeft="16dp"
android:contentDescription="bbc"
tools:background="@color/colorPrimary" />
<TextView
android:id="@+id/articleTitle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginEnd="16dp"
android:layout_toEndOf="@id/imageView"
android:layout_toRightOf="@id/imageView"
android:ellipsize="end"
android:lines="3"
android:maxLines="3"
android:text="1\n2\n3\n" />
<ImageView
android:id="@+id/imageCategory"
android:layout_width="32dp"
android:layout_height="32dp"
android:layout_below="@id/articleTitle"
android:layout_marginStart="16dp"
android:layout_marginLeft="16dp"
android:layout_toEndOf="@id/imageView"
android:layout_toRightOf="@id/imageView"
android:src="@drawable/ic_espn"
tools:background="@color/colorPrimary" />
<TextView
android:id="@+id/articleSourceName"
android:layout_width="wrap_content"
android:layout_height="32dp"
android:layout_below="@id/articleTitle"
android:layout_marginStart="16dp"
android:layout_marginLeft="16dp"
android:layout_toEndOf="@id/imageCategory"
android:layout_toRightOf="@id/imageCategory"
android:gravity="center|start"
android:text="Onefootbal" />
<TextView
android:id="@+id/articleTime"
android:layout_width="wrap_content"
android:layout_height="32dp"
android:layout_below="@id/articleTitle"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_marginStart="16dp"
android:layout_marginEnd="16dp"
android:layout_toEndOf="@id/articleSourceName"
android:layout_toRightOf="@id/articleSourceName"
android:gravity="center|start"
android:text="- 1h"
android:textColor="@android:color/darker_gray"
tools:ignore="NotSibling" />
</RelativeLayout>
</androidx.cardview.widget.CardView>
below NewsRepository.kt
interface NewsRepository {
// Suspend is used to await the result from Deferred
suspend fun getNewsList(): UseCaseResult<Deferred<List<SportNewsResponse>>>
}
class NewsRepositoryImpl(private val sportNewsInterface: SportNewsInterface) : NewsRepository {
override suspend fun getNewsList(): UseCaseResult<Deferred<List<SportNewsResponse>>> {
/*
We try to return a list of cats from the API
Await the result from web service and then return it, catching any error from API
*/
return try {
val result = sportNewsInterface.getNews()
UseCaseResult.Success(result) as UseCaseResult<Deferred<List<SportNewsResponse>>>
} catch (ex: Exception) {
UseCaseResult.Error(ex)
}
}
}
below SportInterface.kt where I am getting ending points
interface SportNewsInterface {
@GET("v2/top-headlines?country=us&apiKey=da331087e3f3462bb534b3b0917cbee9")
suspend fun getNews(): List<SportNewsResponse>
@GET("/v2/top-headlines?sources=espn&apiKey=da331087e3f3462bb534b3b0917cbee9")
fun getEspn(): Deferred<List<SportNewsResponse>>
@GET("/v2/top-headlines?sources=football-italia&apiKey=da331087e3f3462bb534b3b0917cbee9")
fun getFootballItalia(): Deferred<List<SportNewsResponse>>
@GET("/v2/top-headlines?sources=bbc-sport&apiKey=da331087e3f3462bb534b3b0917cbee9")
fun getBBCSport(): Deferred<List<SportNewsResponse>>
}
below SportNewsResponse.kt
data class SportNewsResponse(
val articles: List<Article>,
val status: String,
val totalResults: Int
)
below Article.kt
@Entity(tableName = "news_table")
data class Article(@ColumnInfo(name = "author")val author: String,
val content: String,
val description: String,
val publishedAt: String,
val source: Source,
val title: String,
val url: String,
val urlToImage: String
)
