I have an exisitng code which I integrate with Live data by using retrofit.
Now if I want to integrate databinding, where are all changes to be done to make the code looks perfect?
Here is my code.
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:background="#000000"
android:layout_height="match_parent"
tools:context=".MainActivity">
<LinearLayout
android:id="#+id/linearLayout2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="vertical"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="Android Versions"
android:textColor="#ffffff"
android:textSize="20sp" />
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
items.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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:background="#445566"
android:layout_margin="5dp"
android:layout_height="wrap_content">
<TextView
android:id="#+id/tvFname"
android:padding="5dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top|start"
android:layout_marginTop="8dp"
android:textColor="#ffffff"
android:layout_weight="1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
<TextView
android:id="#+id/tvLname"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center|start"
android:padding="5dp"
android:layout_marginTop="10dp"
android:layout_weight="1"
android:ellipsize="end"
android:textColor="#ffffff"
android:maxLines="5"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/tvFname"/>
</android.support.constraint.ConstraintLayout>
Here is view model class which I integrated
class AndroidViewModel:ViewModel() {
private val mService = RetrofitService()
fun getAndroidData():MutableLiveData<List<AndroidData>>?{
return mService.loadAndroidData()
}
}
Pojo class generated is just a simple one:
data class AndroidData (val name:String, val apiLevel:String)
Service integration:
class RetrofitService {
val liveUserResponse:MutableLiveData<List<AndroidData>> = MutableLiveData()
companion object Factory {
var gson = GsonBuilder().setLenient().create()
fun create(): ApiInterface {
Log.e("retrofit","create")
val retrofit = Retrofit.Builder()
.addCallAdapterFactory(RxJava2CallAdapterFactory.create())
.addConverterFactory(GsonConverterFactory.create(gson))
.baseUrl("https://learn2crack-json.herokuapp.com/api/")
.build()
return retrofit.create(ApiInterface::class.java)
}
}
fun loadAndroidData(): MutableLiveData<List<AndroidData>>? {
Log.e("loadAndroidData","yes")
val retrofitCall = create().getAndroid()
retrofitCall.enqueue(object : Callback<List<AndroidData>> {
override fun onFailure(call: Call<List<AndroidData>>, t: Throwable?) {
Log.e("on Failure :", "retrofit error")
}
override fun onResponse(call: Call<List<AndroidData>>, response: retrofit2.Response<List<AndroidData>>) {
val list = response.body()
for (i in list.orEmpty()){
Log.e("on response 1:", i.name)
}
liveUserResponse.value = list
Log.e("hasActiveObservers 1", liveUserResponse.hasActiveObservers().toString()+" check")
Log.e("on response 2 :", liveUserResponse.toString()+" check")
}
})
return liveUserResponse
}
Main Activity:
class MainActivity : AppCompatActivity(){
private lateinit var linearLayoutManager: LinearLayoutManager
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
linearLayoutManager = LinearLayoutManager(this)
recyclerView.setHasFixedSize(true)
getAndroidVersion()
}
private fun getAndroidVersion() {
Log.e("getAndroidVersion", "yes")
val mAndroidViewModel = ViewModelProviders.of(this#MainActivity).get(AndroidViewModel::class.java)
mAndroidViewModel.getAndroidData()?.observe(this, Observer<List<AndroidData>> { androidList ->
Log.e("list", androidList?.size.toString())
recyclerView.adapter = EmpAdapter(this#MainActivity, androidList as ArrayList<AndroidData>, object :
ItemClickListener {
override fun onItemClick(pos: Int, name:String) {
Toast.makeText(applicationContext, "item "+pos+ "clicked"+ name, Toast.LENGTH_LONG).show()
}
})
})
}
}
Adapter class:
class EmpAdapter(
var context: MainActivity,
var mEmpList: ArrayList<AndroidData>,
private val itemClick:ItemClickListener
) :
RecyclerView.Adapter<EmpAdapter.EmpHolder>() {
override fun getItemCount(): Int {
return mEmpList.size
}
companion object {
var mItemClickListener : ItemClickListener? = null
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): EmpHolder {
val view = LayoutInflater.from(context).inflate(R.layout.items, parent, false)
return EmpHolder(view)
}
override fun onBindViewHolder(holder: EmpHolder, position: Int) {
mItemClickListener = itemClick
holder.tvFname?.text = mEmpList[position].name
holder.tvLname?.text = mEmpList[position].apiLevel
RxView.clicks(holder.mView).subscribe {
mItemClickListener!!.onItemClick(position,mEmpList[position].name)
}
}
class EmpHolder(view: View) : RecyclerView.ViewHolder(view) {
val tvFname = view.tvFname
val tvLname = view.tvLname
val mView = view
}
}
interfaces for retrofit:
interface ApiInterface {
#GET("android")
fun getAndroid(): Call<List<AndroidData>>
}
Now my question is, if I integrate tag and in xml, which variable i need to specify for textview to integrate to connect for textview in adapter? Kindly guide me where are all I need to change to apply, if I use live data
First of all, i strongly recommend to use a Retrofit Adapter that converts the response into LiveData automatically for you. See this example
https://github.com/yasiralijaved/android-architecture-components/blob/master/component_http/src/main/java/com/yasiralijaved/android/arc/component/http/BackendService.java
Secondly there are detailed tutorials out there which can surely help you how to implement Data Bindings in RecyclerView Adapter. A few tutorials are:
https://medium.com/androiddevelopers/android-data-binding-recyclerview-db7c40d9f0e4
https://android.jlelse.eu/how-to-bind-a-list-of-items-to-a-recyclerview-with-android-data-binding-1bd08b4796b4
Do let me know if it is still not clear and i will share some more details.
Happy coding!!
Related
RecyclerView
class RecyclerViewAdapter: RecyclerView.Adapter<RecyclerViewAdapter.RepoViewHolder>(){
inner class RepoViewHolder(val binding: RepoelementBinding): RecyclerView.ViewHolder(binding.root)
private val diffCallBack = object : DiffUtil.ItemCallback<userReposItem>(){
override fun areItemsTheSame(oldItem: userReposItem, newItem: userReposItem): Boolean {
return oldItem.url == newItem.url
}
override fun areContentsTheSame(oldItem: userReposItem, newItem: userReposItem): Boolean {
return oldItem == newItem
}
}
private val differ= AsyncListDiffer(this, diffCallBack)
var repos: List<userReposItem>
get()=differ.currentList
set(value) {differ.submitList(value)}
override fun getItemCount() = repos.size
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RepoViewHolder {
return RepoViewHolder(RepoelementBinding.inflate(
LayoutInflater.from(parent.context),
parent,
false
))
}
override fun onBindViewHolder(holder: RepoViewHolder, position: Int) {
holder.binding.apply{
val repo = repos[position]
urlOfRepo.text = repo.url
nameOfRepo.text= repo.description
}
}
}
RepoService
private const val BASE_URL = "https://api.github.com/"
//private const val ENDPOINT_URL= "https://api.github.com/users/${username}/repos"
interface GitHubReposAPIService{
//using only GetUserRepos
#GET("/users/{username}/repos")
suspend fun getUserRepos(#Path("username") username: String) : Response<List<userReposItem>>
#GET(BASE_URL+"users/{username}/{repo}/language")
suspend fun getLanguages(#Path("username") username:String,
#Path("repo") repo: String) : String
}
object UserRepoAPI{
private val moshi= Moshi.Builder()
.add(KotlinJsonAdapterFactory())
.build()
val retrofitService : GitHubReposAPIService by lazy {
Retrofit.Builder()
.addConverterFactory(MoshiConverterFactory.create(moshi))
.baseUrl(BASE_URL)
.build()
.create(GitHubReposAPIService::class.java)
}
//val retrofitService : GitHubReposAPIService by lazy {
retrofit.create(GitHubReposAPIService::class.java)}
}
Activity with List
const val TAG= "Repos"
class UserProfile : AppCompatActivity() {
private lateinit var userName: String
private lateinit var Repos : RecyclerViewAdapter
private lateinit var binding: ActivityUserProfileBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
// val binding: ViewDataBinding? = DataBindingUtil.setContentView(this,
R.layout.activity_user_profile)
binding= ActivityUserProfileBinding.inflate(layoutInflater)
setContentView(binding.root)
userName = intent.getStringExtra("username").toString()
val viewUserName= findViewById<TextView>(R.id.userDisplay)
viewUserName.text=userName
setupRepos()
lifecycleScope.launchWhenCreated {
val response=try{
UserRepoAPI.retrofitService.getUserRepos(userName)
} catch (e: IOException){
Log.e(TAG, "Might not have internet connection")
return#launchWhenCreated
} catch (e: HttpException){
Log.e(TAG, "HttpException, invalid response")
return#launchWhenCreated
}
if(response.isSuccessful && response.body()!=null){
Repos.repos=response.body()!!
}else{
Log.e(TAG, "Response not succesful")
}
}
}
private fun setupRepos() = binding.recyclerView?.apply{
Repos = RecyclerViewAdapter()
adapter = Repos
layoutManager = LinearLayoutManager(this#UserProfile)
}
}
Data class
I only want two parameters ( url of repo and its description). There is many more information, but I only need those 2 for every repo.
#JsonClass(generateAdapter = true)
#JsonIgnoreProperties(ignoreUnknown = true)
data class userReposItem(
#Json(name = "description")
val description: String? = "",
#Json(name = "url")
val url: String? = "",
) : Parcelable{
constructor(parcel: Parcel) : this(
parcel.readString()!!,
parcel.readString()!!
) {
}
override fun writeToParcel(parcel: Parcel, flags: Int) {
parcel.writeString(description)
parcel.writeString(url)
}
override fun describeContents(): Int {
return 0
}
companion object CREATOR : Parcelable.Creator<userReposItem> {
override fun createFromParcel(parcel: Parcel): userReposItem {
return userReposItem(parcel)
}
override fun newArray(size: Int): Array<userReposItem?> {
return arrayOfNulls(size)
}
}
}
Layouts:
Main layout for printing list of repos. At the top of layout we have name of user and below should be list of repos (but as I mentioned it doesnt work)
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".UserProfile">
<TextView
android:id="#+id/userDisplay"
android:layout_width="374dp"
android:layout_height="38dp"
android:layout_marginStart="16dp"
android:layout_marginTop="4dp"
android:layout_marginEnd="21dp"
android:text="#string/username"
app:layout_constraintBottom_toTopOf="#+id/recyclerView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="409dp"
android:layout_height="547dp"
android:layout_marginBottom="4dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
List item
I would like to print url of repo and its name ("description" as shown in github API)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:orientation="vertical">
<TextView
android:id="#+id/urlOfRepo"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="12dp"
android:layout_marginEnd="89dp"
android:layout_marginBottom="489dp"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/nameOfRepo" />
<TextView
android:id="#+id/nameOfRepo"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/urlOfRepo" />
</LinearLayout>
I hope is all well with you.
I have constructed my code and build according the MVP style as well pulling JSON data but when I run the the code the horizontal recycle view and the JSON data is not being displayed. I tried going through every line of code and watching other tutorials but still no results.
Here is below my main activity:
class ProductCategoryActivity : BaseMvpActivity<ProductCategoryActivityView, ProductCategoryActivityPresnter> (),
ProductCategoryActivityView, CategoryAdapter.onItemClickListener{
private lateinit var binding: FragmentProductCategoryBinding
val data :MutableList<CateogryResponse> = ArrayList()
val adapter= CategoryAdapter(data, this)
#Inject
lateinit var presenter: ProductCategoryActivityPresnter
#Inject
lateinit var progressDialog: ProgressDialog
override fun onCreateComponent() {
userComponent.plus(CategoryActivityModule(this)).inject(this)
}
override fun providePresenter(): ProductCategoryActivityPresnter {
return presenter
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = FragmentProductCategoryBinding.inflate(layoutInflater)
val view = binding.root
setContentView(view)
presenter.fetchcatogries()
showdata(ArrayList())
}
override fun showError(message: String) {
}
override fun showProgress() {
}
override fun hideProgress() {
}
override fun showdata(data: ArrayList<CateogryResponse>) {
val layoutManager = LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false)
recyclerViewPrimary.layoutManager = layoutManager
recyclerViewPrimary.setHasFixedSize(true)
recyclerViewPrimary.adapter = adapter
for(i in data)
data.add(CateogryResponse("product"))
}
override fun onItemClick(position: Int) {
Toast.makeText(this, "Item $position clicked", Toast.LENGTH_SHORT).show()
val clickedItem = data[position]
adapter.notifyItemChanged(position)
}
}
Here is my presenter:
#ActivityScope
class ProductCategoryActivityPresnter #Inject constructor(
private val stringProvider: StringProvider,
#AndroidScheduler private val observeOnScheduler: Scheduler,
#IOScheduler private val subscribeOnScheduler: Scheduler,
private val getCategoryUseCase: CategoryUseCase
) : BasePresenter<ProductCategoryActivityView>() {
lateinit var catogriesservice: CategoryRepositoryImpl
val catogriesLoadError = MutableLiveData<Boolean>()
val loading = MutableLiveData<Boolean>()
var catogries: ArrayList<CateogryResponse> = arrayListOf()
override fun onCreatePresenter(savedInstanceState: Bundle?) {
}
override fun onSaveInstanceState(outState: Bundle?) {
}
override fun onLoadData(arguments: Bundle?) {
fetchcatogries()
}
fun fetchcatogries() {
getCategoryUseCase.execute()
.observeOn(observeOnScheduler)
.subscribeOn(subscribeOnScheduler)
.subscribe(
SingleRequestSubscriber(
{
it
if (it != null && it.size > 0) {
catogries.removeAll(catogries)
catogries.addAll(it)
}
},
onFailure = { appException ->
view?.showError(
ErrorHandler.getErrorMessage(
appException,
stringProvider
)
)
},
onApiError = { apiException ->
view?.showError(
ErrorHandler.getErrorMessage(
apiException,
stringProvider
)
)
},
onAuthenticationError = { requestxception ->
view?.showError(
ErrorHandler.getErrorMessage(
requestxception,
stringProvider
)
)
},
onShowProgress = {
if (it) {
view?.showProgress()
} else {
view?.hideProgress()
}
},
onSubscribed = {
disposable.add(it)
})
)
}
}
Here is my view:
interface ProductCategoryActivityView {
fun showError(message: String)
fun showProgress()
fun hideProgress()
fun showdata ( data: ArrayList<CateogryResponse>)
}
Here is my adapter:
class CategoryAdapter(
private val data: List<CateogryResponse>,
private val listener: onItemClickListener
) : RecyclerView.Adapter<CategoryAdapter.ViewHolder>() {
private val items: MutableList<CardView>
init {
this.items = ArrayList()
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val v = LayoutInflater.from(parent.context)
.inflate(R.layout.fragment_category_adapter, parent, false)
return ViewHolder(v)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.tvTitle.text = data[position].product
items.add(holder.card)
}
override fun getItemCount(): Int {
return data.size
}
inner class ViewHolder(itemView: View
) : RecyclerView.ViewHolder(itemView),
View.OnClickListener {
val tvTitle: TextView = itemView.featured_title
val card: CardView = itemView.CardView
init {
itemView.setOnClickListener(this)
}
override fun onClick(v: View?) {
val position: Int = adapterPosition
if (position != RecyclerView.NO_POSITION) {
listener.onItemClick(position)
}
}
}
interface onItemClickListener {
fun onItemClick(position: Int)
}
}
Image:
Fragment Category Adapter:
android:id="#+id/CardView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
app:cardCornerRadius="2dp"
app:cardElevation="8dp">
<!-- We Will Add here the card & ImageViews -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="15dp">
<ImageView
android:id="#+id/featured_image"
android:layout_width="match_parent"
android:layout_height="140dp"
android:scaleType="centerCrop" />
<TextView
android:id="#+id/featured_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineHeight="23dp"
android:text="Chairs"
android:textColor="#color/colorAccent"
android:textSize="20sp" />
<TextView
android:id="#+id/featured_desc"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="asbkd asudhlasn saudnas jasdjasl hisajdl asjdlnas" />
</LinearLayout>
</androidx.cardview.widget.CardView>
Fragment Product Category:
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#fafcfe"
tools:context="ui.category.ProductCategoryActivity">
<ImageView
android:id="#+id/imageView3"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
/>
<ImageView
android:id="#+id/imageView"
android:layout_width="wrap_content"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/constraintLayout"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginTop="48dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="#+id/imageView"
app:layout_constraintTop_toTopOf="parent">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerViewPrimary"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="48dp"
android:layout_marginTop="20dp"
android:text="#string/topselling"
android:textSize="18sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/constraintLayout" />
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/constraintLayout2"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="32dp"
android:layout_marginLeft="32dp"
android:layout_marginTop="16dp"
app:layout_constraintBottom_toTopOf="#+id/imageView3"
app:layout_constraintEnd_toEndOf="#+id/constraintLayout"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/textView">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerViewSecondary"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
<ImageView
android:id="#+id/imageView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="32dp"
app:layout_constraintBottom_toBottomOf="#+id/imageView3"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
/>
<TextView
android:id="#+id/textViewCategories"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="48dp"
android:layout_marginTop="20dp"
android:layout_marginBottom="15dp"
android:text="#string/catogries"
android:textSize="18sp"
app:layout_constraintBottom_toTopOf="#+id/constraintLayout"
app:layout_constraintStart_toStartOf="parent"
tools:layout_editor_absoluteX="39dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
Not sure what went wrong.
If someone can point it out or show me what needs to be done to be able to display the data in horzintal recycle view, I would be really thanlful
You should update your recycler view adapter once your fetch call is executed, not before it ends.
Modify your fetchcatogries declaration so it accepts a callback method, which will be executed after the data are loaded.
This method will accept a list object as a parameter, which you will manage in your ProductCategoryActivity to populate the RecyclerView.
fun fetchcatogries(callback: (MutableList<CateogryResponse>) -> Unit) {
getCategoryUseCase.execute()
.observeOn(observeOnScheduler)
.subscribeOn(subscribeOnScheduler)
.subscribe(
SingleRequestSubscriber(
{ categories ->
callback(categories)
},
...
)
}
You can now edit your onCreate and showdata methods in ProductCategoryActivity like this:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = FragmentProductCategoryBinding.inflate(layoutInflater)
val view = binding.root
setContentView(view)
presenter.fetchcatogries { categories ->
showdata(categories as ArrayList<CateogryResponse>)
}
}
override fun showdata(data: ArrayList<CateogryResponse>) {
val layoutManager = LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false)
recyclerViewPrimary.layoutManager = layoutManager
recyclerViewPrimary.setHasFixedSize(true)
recyclerViewPrimary.adapter = CategoryAdapter(data.toList(), this)
}
I'm trying to make simple app to show list of cocktails using data binding and retrofit. I can see by logging interceptor request is 200 but when i debug i can see the result list is null.debug screenshot
responce screenshot
Fragment class
class CocktailListFragment : Fragment() {
private val viewModel: CocktailListViewModel by lazy {
ViewModelProvider(this).get(CocktailListViewModel::class.java)
}
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
val binding = CocktailListFragmentBinding.inflate(inflater)
binding.lifecycleOwner = this
setHasOptionsMenu(true)
binding.cocktail = viewModel
binding.cocktailList.adapter = CocktailListAdapter()
return binding.root
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.filter_menu, menu)
super.onCreateOptionsMenu(menu, inflater)
}
}
ViewModel
class CocktailListViewModel : ViewModel() {
private val _cocktails = MutableLiveData<CocktailsList>()
val cocktails: LiveData<CocktailsList>
get() = _cocktails
private var viewModelJob = Job()
private val coroutineScope = CoroutineScope(viewModelJob + Dispatchers.Main)
init {
getCocktails()
}
private fun getCocktails() {
coroutineScope.launch {
val getCocktailsDeferred = CocktailsApi.RETROFIT_SERVICE.getCocktailsAsync()
try {
val result = getCocktailsDeferred.await()
_cocktails.value = result
} catch (e: Exception) {
Log.d("error", "error")
}
}
}
override fun onCleared() {
super.onCleared()
viewModelJob.cancel()
}
}
Adapter
class CocktailListAdapter :
ListAdapter<Cocktail, CocktailListAdapter.CocktailListViewHolder>(DiffCallback) {
class CocktailListViewHolder(private var binding: CocktailItemBinding) :
RecyclerView.ViewHolder(binding.root) {
fun bind(cocktail: Cocktail) {
binding.cocktail = cocktail
binding.executePendingBindings()
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CocktailListViewHolder {
return CocktailListViewHolder(CocktailItemBinding.inflate(LayoutInflater.from(parent.context)))
}
override fun onBindViewHolder(holder: CocktailListViewHolder, position: Int) {
val cocktail = getItem(position)
holder.bind(cocktail)
}
companion object DiffCallback : DiffUtil.ItemCallback<Cocktail>() {
override fun areItemsTheSame(oldItem: Cocktail, newItem: Cocktail): Boolean {
return oldItem === newItem
}
override fun areContentsTheSame(oldItem: Cocktail, newItem: Cocktail): Boolean {
return oldItem.id == newItem.id
}
}
}
BindingAdapters
#BindingAdapter("listData")
fun bindRecyclerView(recyclerView: RecyclerView, data: CocktailsList?) {
val adapter = recyclerView.adapter as CocktailListAdapter
adapter.submitList(data?.list)
}
#BindingAdapter("strDrinkThumb")
fun bindImage(imgView: ImageView, imgUrl: String?) {
imgUrl?.let {
val imgUri = imgUrl.toUri().buildUpon().scheme("https").build()
Picasso.get()
.load(imgUri)
.placeholder(R.drawable.loading_animation)
.error(R.drawable.ic_broken_image)
.into(imgView)
}
}
ApiService
private const val BASE_URL =
"https://www.thecocktaildb.com"
private val gson = GsonConverterFactory.create(GsonBuilder().create())
val logging = HttpLoggingInterceptor()
val okhttpClient = OkHttpClient.Builder()
.addInterceptor(logging.setLevel(HttpLoggingInterceptor.Level.BODY))
.build()
private val retrofit = Retrofit.Builder()
.baseUrl(BASE_URL)
.client(okhttpClient)
.addConverterFactory(gson)
.addCallAdapterFactory(CoroutineCallAdapterFactory())
.build()
interface CocktailsApiService {
#GET("./api/json/v1/1/filter.php?c=Ordinary_Drink")
fun getCocktailsAsync():
Deferred<CocktailsList>
}
object CocktailsApi {
val RETROFIT_SERVICE: CocktailsApiService by lazy {
retrofit.create(CocktailsApiService::class.java)
}
}
data classes
data class CocktailsList(
val list: List<Cocktail>
)
data class Cocktail (
#SerializedName("idDrink")
val id: String,
#SerializedName("strDrinkThumb")
val drinkImg: String,
#SerializedName("strDrink")
val drinkTitle: String
)
cocktail_list_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="cocktail"
type="com.example.coctaildb.cocktaillist.CocktailListViewModel" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appBarLayout2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:elevation="30dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.appbar.MaterialToolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#android:color/white"
app:menu="#menu/filter_menu"
app:title="#string/drinks"
app:titleTextColor="#android:color/black" />
</com.google.android.material.appbar.AppBarLayout>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/cocktail_list"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/appBarLayout2"
app:listData="#{cocktail.cocktails}"
tools:listitem="#layout/cocktail_item" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
cocktail_item.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="cocktail"
type="com.example.coctaildb.network.Cocktail" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/cocktail_img"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginStart="20dp"
android:layout_marginTop="20dp"
android:layout_marginBottom="20dp"
app:strDrinkThumb="#{cocktail.drinkImg}"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:srcCompat="#tools:sample/avatars" />
<TextView
android:id="#+id/cocktail_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="21dp"
android:layout_marginEnd="20dp"
android:fontFamily="#font/roboto"
android:text="#{cocktail.drinkTitle}"
android:textColor="#7E7E7E"
android:textSize="16sp"
app:layout_constraintBottom_toBottomOf="#+id/cocktail_img"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#+id/cocktail_img"
app:layout_constraintTop_toTopOf="#+id/cocktail_img" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
I suppose i messed up with data type in binding, please help.
I think problem is in serialisation. try
data class CocktailsList(
#SerializedName("drinks")
val list: List<Cocktail>
)
I am trying to Implement Recycler View in Activity after parsing data using Retrofit.But the problem is it shows Recycler view cannot be null even after initializing inside onCreate method before accessing.
Mainactitivty.kt
class MainActivity : AppCompatActivity() {
lateinit var myRecyclerView: RecyclerView
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
retroInstance = RetroInstance()
val instance = retroInstance.getInstance()
val api = instance.create(RetroInterface::class.java)
val callAll=api.getAllDetail()
callAll.enqueue(object :retrofit2.Callback<ModelAll>{
override fun onFailure(call: Call<ModelAll>, t: Throwable) {
Toast.makeText(applicationContext,t.message,Toast.LENGTH_LONG).show()
}
override fun onResponse(call: Call<ModelAll>, response: Response<ModelAll>) {
val allDetail=response.body()!!
myRecyclerView=findViewById(R.id.recyclerView)
myRecyclerView.layoutManager=LinearLayoutManager(this#MainActivity)
myRecyclerView.adapter=CoronaAdapter(allDetail)
}
})
}
}
Activity with recycler view included
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".AllCountries">
<SearchView
android:id="#+id/searchView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="2dp"
android:layout_marginTop="5dp"
android:layout_marginEnd="2dp"
android:background="#drawable/custom_search"
android:elevation="5dp"
android:queryHint="Search here..."
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginTop="5dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/searchView" />
</androidx.constraintlayout.widget.ConstraintLayout>
Logcat
https://gist.github.com/devpawann/af3cef9d204a6f99cd7ed11937684fa2
EDIT:- Issue solved, the mistake was that I initializes recycler view in another activity class
You can maybe try something like this:
class MainActivity : AppCompatActivity() {
private var allDetails: MutableList<ModelAll> = ArrayList()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
retroInstance = RetroInstance()
val instance = retroInstance.getInstance()
val api = instance.create(RetroInterface::class.java)
val callAll=api.getAllDetail()
//Init your recyclerview
val myRecyclerView = findViewById(R.id.recyclerView)
myRecyclerView.layoutManager=LinearLayoutManager(this)
val coronaAdapter = CoronaAdapter(allDetails)
myRecyclerView.adapter = adapter
callAll.enqueue(object :retrofit2.Callback<ModelAll>{
override fun onFailure(call: Call<ModelAll>, t: Throwable) {
Toast.makeText(applicationContext,t.message,Toast.LENGTH_LONG).show()
}
override fun onResponse(call: Call<ModelAll>, response: Response<ModelAll>) {
if(response.isSucessful()){
allDetails = response.body()!!
coronaAdapter.notifyDataSetChanged()
}
}
})
}
EDIT: The issue was that the recyclerView was in another layout that the one inflated.
Your recyclerView has not been instantiated(currently it is referring to null).
Add this line
recyclerview = findViewById(R.id.recyclerView)
Or if you are using Android Extensions then make sure you are using correct recyclerview
First of all, I'm new to Android/Java/Kotlin development. I'm using Retrofit2 to retrieve data from Udacity API. I can see the response in the Logcat, but when I try to display it in RecyclerView there is just a blank screen. I think the error is in the MainActivity, but I'm still clueless and need help.
My model classes
class Course(var title: String,
var subtitle: String,
var key: String,
var instructors: List<Instructor>,
var expected_learning: String,
var required_knowledge: String)
class Instructor(var name: String,
var bio: String)
My interface
interface ApiServiceInterface {
#GET("courses")
fun list() : Call<UdacityCatalog>
}
My adapter
class CourseAdapter(val listCourses: ArrayList<Course?>, val context: Context) : RecyclerView.Adapter<CourseAdapter.CourseViewHolder>() {
class CourseViewHolder(viewItem: View) : RecyclerView.ViewHolder(viewItem) {
val courseTitle = viewItem.findViewById<TextView?>(R.id.tv_title) as TextView
val courseSubtitle = viewItem.findViewById<TextView?>(R.id.tv_subtitle) as TextView
val courseKey = viewItem.findViewById<TextView?>(R.id.tv_course_key) as TextView
val instructorName = viewItem.findViewById<TextView?>(R.id.tv_instructor_name) as TextView
}
override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): CourseViewHolder {
val viewHolder = LayoutInflater.from(parent?.context).inflate(R.layout.activity_item_list, parent, false)
val itemViewHolder = CourseViewHolder(viewHolder)
return itemViewHolder
}
override fun onBindViewHolder(holder: CourseViewHolder?, position: Int) {
holder?.courseTitle?.text = listCourses[position].title
holder?.courseSubtitle?.text = listCourses[position].subtitle
holder?.courseKey?.text = listCourses[position].key
holder?.instructorName?.text = listCourses[position].instructors.toString()
}
override fun getItemCount(): Int = listCourses.size
}
My MainActivity -- I think the error is in here, but I haven't figured it out yet
class MainActivity : AppCompatActivity() {
internal val TAG = "Testing Retrofit2 API"
lateinit var mRecyclerView: RecyclerView
lateinit var mCourseAdapter: RecyclerView.Adapter<CourseAdapter.CourseViewHolder>
val listCourse = arrayListOf<Course?>()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main_recyclerview)
mRecyclerView = findViewById<RecyclerView?>(R.id.id_recycler_view) as RecyclerView
val mLayoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)
mRecyclerView.layoutManager = mLayoutManager
mRecyclerView.setHasFixedSize(true)
mCourseAdapter = CourseAdapter(listCourse, applicationContext)
mRecyclerView.adapter = mCourseAdapter
mCourseAdapter.notifyDataSetChanged()
val call = RetrofitInitializer().createService().list()
call.enqueue(object : Callback<UdacityCatalog> {
override fun onResponse(call: Call<UdacityCatalog>, response: Response<UdacityCatalog>) {
response.body()
if (!response.isSuccessful) {
Log.i(TAG, "[ ERROR ] " + response.code())
} else {
if (listCourse.isEmpty()) {
Toast.makeText(applicationContext, "Empty list!", Toast.LENGTH_LONG).show()
} else {
Toast.makeText(applicationContext, "Full list!", Toast.LENGTH_LONG).show()
}
val catalog = response.body()
for (c in catalog!!.courses!!) {
Log.i(TAG, String.format("%s: %s", c.title, c.subtitle, c.key, c.required_knowledge, c.expected_learning))
for (i in c.instructors!!) {
Log.i(TAG, i.name)
}
Log.i(TAG, "\n****************************************************************************************************\n")
}
}
}
override fun onFailure(call: Call<UdacityCatalog>?, t: Throwable?) {
Log.d(TAG, "onFailure() : " + t?.message)
}
})
}
}
An initializer class for Retrofit instance
class RetrofitInitializer {
companion object Factory {
val BASE_URL = "https://www.udacity.com/public-api/v0/"
}
private val retrofit = Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build()
fun createService(): ApiServiceInterface = retrofit.create(ApiServiceInterface::class.java)
}
My RecyclerView xml file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:orientation="vertical"
android:paddingBottom="16dp"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingTop="16dp"
tools:context="activities.MainActivity">
<android.support.v7.widget.RecyclerView
android:id="#+id/id_recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
</android.support.v7.widget.RecyclerView>
</LinearLayout>
My CardView xml file
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="16dp"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="16dp"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingTop="16dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="#string/udacity_catalog"
android:textAppearance="?android:textAppearanceLarge"
android:textColor="#9C27B0"
android:textStyle="bold" />
<TextView
android:id="#+id/tv_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:gravity="start"
android:hint="#string/hint_title"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="#000000" />
<TextView
android:id="#+id/tv_subtitle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:gravity="start"
android:hint="#string/hint_subtitle"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="#000000" />
<TextView
android:id="#+id/tv_course_key"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:gravity="start"
android:hint="#string/hint_key"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="#000000" />
<TextView
android:id="#+id/tv_instructor_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:gravity="start"
android:hint="#string/hint_name"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="#000000" />
</LinearLayout>
</android.support.v7.widget.CardView>
You have an empty list of courses (listCourse) in your Activity. You pass that empty list to the adapter via it's constructor.
That list stays empty even after you fetched the courses. So the adapter / RecyclerView stays empty.
Try creating the adapter after you fetched the courses, with
mCourseAdapter = CourseAdapter(catalog!!.courses!!, applicationContext)
or have a courses property in your adapter lile
YourAdapter(...) {
var courses = listOf(Course)
}
and then in your Activity (after fetching the courses):
adapter.courses = catalog!!.courses!!
adapter.notifyDataSetChanged()