Develop Reference

Kotlin adapter Required: Int Found: String?

I have API data which ID's are uuid (strings) and not (integer) and when I want to get those ids in my adapter it says
Type mismatch.
Required:
Int
Found:
String?
Sample of API items
{
"id":"0ade1bfb-6d02-4a1f-9cd4-dc88fa8aadbd",
"name":"ABC",
"photo":null // if not null, will be full URL of image (https://example.com/img/abc.jpg)
}
Code
Adapter (commented)
class ServicesAdapter(private val serviceList: List<Service>) : RecyclerView.Adapter<ServicesAdapter.ServiceViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ServiceViewHolder {
val imageView =
LayoutInflater.from(parent.context).inflate(R.layout.service_item, parent, false)
return ServiceViewHolder(imageView)
}
override fun onBindViewHolder(holder: ServiceViewHolder, position: Int) {
val currentItem = serviceList[position]
holder.imageView.setImageResource(currentItem.photo) <-- error line
holder.textView.text = currentItem.name
}
override fun getItemCount() = serviceList.size
class ServiceViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val imageView: ImageView = itemView.imageView
val textView: TextView = itemView.textView2
}
}
Activity
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
run("api_url")
}
fun run(url: String) {
val request = Request.Builder()
.url(url)
.build()
client.newCall(request).enqueue(object : Callback {
override fun onFailure(call: Call, e: IOException) {}
override fun onResponse(call: Call, response: Response) {
val list: ArrayList<Service> = ArrayList()
getServices(response.body()!!.string(), list)
recycler.layoutManager = LinearLayoutManager(this#MainActivity)
recycler.adapter = ServicesAdapter(list)
}
})
}
fun getServices(response: String, list: ArrayList<Service>) {
var jsonObject = JSONObject(response)
val jsonArray = jsonObject.getJSONArray("data")
for (i in 0 until jsonArray.length()) {
val jsonObject1 = jsonArray.getJSONObject(i)
var listingObject = Service(
jsonObject1.getString("id"),
jsonObject1.getString("name"),
jsonObject1.getString("photo")
)
list.add(listingObject)
}
}
Class
class Service (val id: String?, val name: String?, val photo: String?) {
}
Any idea?

Add the following lines of code in your OnBindViewHolder to load images from the URL
currentItem.photo?.apply{
Glide.with(holder.imageView.context)
.load(this)
.into(holder.imageView)
}

holder.imageView.setImageResource(currentItem.photo)
this method requires int value, which you are providing null(treated as null string)
try replacing null as blank while parsing json data
or you can use this
public static boolean isBlankOrNull(String value)
{
return (value == null || value.equals("") || value.equals("null") || value.trim().equals(""));
}
like this
holder.imageView.setImageResource(isBlankOrNull(currentItem.photo) ? 0 : currentItem.photo)

Just set image when you are getting it in response i.e. its value is not empty or null.Also you need to use any library to set image to imageview for example You can use Square's Picasso and can update your code as below
if(!TextUtils.isEmpty(currentItem.photo))
Picasso
.get()
.load(currentItem.photo)
.into(holder.imageView)

RecyclerView make endless scrolling with JSON

I'm trying to make my Android App (I'm only experienced in iOS).
I created a RecyclerView that gets the data from a web. I tried everything to implement endless scrolling to load more items, but when I call the function to get the items, the entire RecyclerView loads again and no attach the new results on the bottom.
This is my code:
ConversationUser.kt
data class ConversationUser(
val message_nickname: String,
val message_image_thumb: String,
val message_large_thumb: String,
val message_modified: String,
val message_status: String,
val message_unread: Int,
val conv_id: String,
val message_dest: String) {
}
ConversacionesActivity.kt
class ConversacionesActivity : AppCompatActivity() {
// MARK: Variables
var user_token = ""
var user_id = ""
override fun onCreate(savedInstanceState: Bundle?) {
// User Defaults
val sharedPreferences = getSharedPreferences("Preferences", Context.MODE_PRIVATE)
user_token = sharedPreferences.getString("user_token", "")!!
user_id = sharedPreferences.getString("user_id", "")!!
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_conversaciones)
recyclerConv.addItemDecoration(DividerItemDecoration(this, LinearLayoutManager.VERTICAL))
getConversationsData()
recyclerConv.setLoadingListener(object : LoadingListener {
override fun onRefresh() {
//refresh data here
}
override fun onLoadMore() {
// load more data here
getConversationsData()
}
})
}
fun getConversationsData() {
val httpAsync = "https://mywebsite.com/conversations/${user_token}"
.httpPost()
.responseString { request, response, result ->
when (result) {
is Result.Failure -> {
val ex = result.getException()
println(ex)
}
is Result.Success -> {
val data = result.get()
runOnUiThread {
val conversaciones = processJson(data)
show(conversaciones)
return#runOnUiThread
}
}
}
}
httpAsync.join()
}
fun processJson(json: String): List<ConversationUser> {
val gson: Gson = GsonBuilder().create()
val conversaciones: List<ConversationUser> = gson.fromJson(
json,
Array<ConversationUser>::class.java
).toList()
return conversaciones
}
fun show(conversaciones: List<ConversationUser>) {
recyclerConv.layoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)
recyclerConv.adapter = AdaptadorConv(conversaciones, this, user_token, user_id)
}
AdaptadorConv.kt
class AdaptadorConv(
val conversaciones: List<ConversationUser> = ArrayList(),
val context: Context,
val user_token: String,
val user_id: String) : RecyclerView.Adapter<AdaptadorConv.ConvViewHolder>() {
override fun onBindViewHolder(holder: ConvViewHolder, position: Int) {
holder.convName.text = conversaciones[position].message_nickname
holder.convTime.text = conversaciones[position].message_modified
}
override fun getItemCount(): Int {
return conversaciones.size - 1
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ConvViewHolder {
val view: View = LayoutInflater.from(parent.context).inflate(
R.layout.conversaciones,
parent,
false
)
return ConvViewHolder(view)
}
class ConvViewHolder(vista: View): RecyclerView.ViewHolder(vista) {
val convImg: ImageView = itemView.findViewById(R.id.convImg)
val convStatus: ImageView = itemView.findViewById(R.id.convStatus)
val convName: TextView = itemView.findViewById(R.id.convName)
val convUnread: TextView = itemView.findViewById(R.id.convUnread)
val convTime: TextView = itemView.findViewById(R.id.convTime)
}
Thanks for any help or hint.

Please check your show () method, you are creating new Adapter every time with the new dataset. You have to append the new items to the adapter's list and adapter should be set to list once. Helpful tutorial can be found at here.

Not sure where to implements parcelable ArrayList after click item in RecyclerView

I wanna pass some of informations of the selected item to be viewed in new activity AboutApp.kt, but here I test by one info only (name). I do not have any trouble with RecyclerView, it works. I've seen many ways to do parcelable ArrayList object but feeling confuse where activity to be implemented, so it's getting error in MainActivity and AboutApp (destination intent).
A piece code MainActivity.kt getting error in showSelectedHerbal, when I use position to putExtra
class MainActivity : AppCompatActivity() {
private lateinit var rvHerbal: RecyclerView
private var list: ArrayList<Herbal> = arrayListOf()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
rvHerbal = findViewById(R.id.rv_herbal)
rvHerbal.setHasFixedSize(true)
list.addAll(HerbalData.listData)
showRecyclerList()
}
private fun showRecyclerList() {
rvHerbal.layoutManager = LinearLayoutManager(this)
val listHerbalAdapter = ListHerbalAdapter(list)
rvHerbal.adapter = listHerbalAdapter
listHerbalAdapter.setOnItemClickCallback(object : ListHerbalAdapter.OnItemClickCallback {
override fun onItemClicked(data: Herbal) {
showSelectedHerbal(data)
}
})
}
........
private fun showSelectedHerbal(data: Herbal) {
val moveIntent = Intent(this, AboutApp::class.java)
moveIntent.putExtra("Example_Item", list!![position])
this.startActivity(moveIntent)
}
.......
}
A piece code from AboutApp.kt that getting error in herbalName(). I know that I haven't implemented the parcelable so it's wrong
val intent = intent
val herbalData: HerbalData = intent.getParcelableExtra("Example_Item")
val title: String = herbalData.herbalName()
val itemName = findViewById<TextView>(R.id.item_name)
itemName.text = title
I'm so sorry, I attach you some of activities that I confuse may be one of them is the right place to be implement parcelable. Here is my data class Herbal.kt
data class Herbal(
var name: String = "",
var detail: String = "",
var photo: Int = 0
)
A piece code of the object HerbalData.kt
object HerbalData {
private val herbalName = arrayOf("Cengkeh",
"Ginseng",
"Jahe")
..........
val listData: ArrayList<Herbal>
get() {
val list = arrayListOf<Herbal>()
for (position in herbalName.indices) {
val herbal = Herbal()
herbal.name = herbalName[position]
herbal.detail = herbalDetail[position]
herbal.photo = herbalImage[position]
list.add(herbal)
}
return list
}
}
Help me please where activity to be write the parcelable ArrayList and how to fix it. Thanks in advance for any help.

First of all the error in your AboutApp.kt is because you have herbalName private in your HerbalData object. Remove the private modifier to access it there.
Just add #Parcelize annotation over your data class to automatically generate writeToParcel and createFromParcel methods for you!
#Parcelize
data class Herbal(...) : Parcelable
Add this in your build.gradle file:
androidExtensions {
features = ["parcelize"]
}
PS: Reference: https://medium.com/#BladeCoder/a-study-of-the-parcelize-feature-from-kotlin-android-extensions-59a5adcd5909

I recommend you read this.
You just have to make the Herbal class Parcelable.
data class Herbal(
var name: String = "",
var detail: String = "",
var photo: Int = 0
) : Parcelable {
companion object {
#JvmField
val CREATOR = object : Parcelable.Creator<Herbal> {
override fun createFromParcel(parcel: Parcel) = Herbal(parcel)
override fun newArray(size: Int) = arrayOfNulls<Herbal>(size)
}
}
private constructor(parcel: Parcel) : this(
name = parcel.readString(),
detail = parcel.readString(),
photo = parcel.readInt(),
)
override fun writeToParcel(parcel: Parcel, flags: Int) {
parcel.writeString(name)
parcel.writeString(detail)
parcel.writeInt(photo)
}
override fun describeContents() = 0
}

How to wait and execute code after AsyncHttpClient() Done?

I want to take data from API using AsyncHttpClient(), after that, I show the data to recycle view. but when trying to debug my code is run show the data to recycle view which is no data because not yet finish setData using AsyncHttpClient(). my question is how to run setData recycle view adapter after my setLeague is finish getting data? Sorry, I am a newbie and I put my code below. Please help, I already try using async-await but doesn't work.
This is my ViewModel Class
val footballLeagueList = MutableLiveData<ArrayList<league>>()
internal fun setLeague(){
val client = AsyncHttpClient()
val client2 = AsyncHttpClient()
val listItems = ArrayList<league>()
val leagueListUrl = "https://www.thesportsdb.com/api/v1/json/1/all_leagues.php"
val leagueDetailUrl = "https://www.thesportsdb.com/api/v1/json/1/lookupleague.php?id="
client.get(leagueListUrl, object : AsyncHttpResponseHandler(){
override fun onSuccess(
statusCode: Int,
headers: Array<out Header>?,
responseBody: ByteArray?
) {
try{
val result = String(responseBody!!)
val responseObject = JSONObject(result)
for(i in 0 until 10){
val list = responseObject.getJSONArray("leagues")
val leagues = list.getJSONObject(i)
val leaguesItems = league()
val detailUrl = leagueDetailUrl + leagues.getString("idLeague")
leaguesItems.id = leagues.getString("id")
leaguesItems.name = leagues.getString("strLeague")
leaguesItems.badgeUrl = leagues.getString( "https://www.thesportsdb.com/images/media/league/badge/dqo6r91549878326.png")
listItems.add(leaguesItems)
}
footballLeagueList.postValue(listItems)
}catch (e: Exception){
Log.d("Exception", e.message.toString())
}
}
override fun onFailure(
statusCode: Int,
headers: Array<out Header>?,
responseBody: ByteArray?,
error: Throwable?
) {
Log.d("Failed", "On Failure")
}
})
}
internal fun getLeague(): LiveData<ArrayList<league>> {
return footballLeagueList
}
And this is my MainActivity
class MainActivity : AppCompatActivity() {
private lateinit var mainViewModel: MainViewModel
private lateinit var adapterLeague: leagueAdapter
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
adapterLeague = leagueAdapter()
adapterLeague.notifyDataSetChanged()
verticalLayout {
lparams(matchParent, matchParent)
recyclerView {
layoutManager = GridLayoutManager(context, 2)
adapter = adapterLeague
}
}
mainViewModel = ViewModelProvider(this, ViewModelProvider.NewInstanceFactory())
.get(MainViewModel::class.java)
mainViewModel.setLeague()
mainViewModel.getLeague().observe(this, Observer { leaguesItems ->
if(leaguesItems != null){
adapterLeague.setData(leaguesItems)
}
})
}
}

Sorting data from json in Kotlin

I have data from json file which I display in recyclerview in my app. I'm trying to sort this data by year. That's how my code looks:
In MainActivity.kt everythings happend in fetchJson() function
private fun fetchJson(jsonUrl: String) {
Log.d(TAG, "Attempting to fetch json")
val request = okhttp3.Request.Builder().url(jsonUrl).build()
val client = OkHttpClient()
client.newCall(request).enqueue(object: Callback {
override fun onFailure(call: Call, e: IOException) {
Log.d(TAG, "Failed to execute request")
}
override fun onResponse(call: Call, response: Response) {
val body = response.body()?.string()
Log.d(TAG, "$body")
val gson = GsonBuilder().create()
val homeFeed = gson.fromJson(body, HomeFeed::class.java)
homeFeed.standups.sortedWith(compareBy({it.year}))
runOnUiThread {
rv.adapter = Adapter(homeFeed)
}
}
})
}
fun <T> compareBy(vararg selectors: (T) -> Comparable<*>?): Comparator<T> {
return Comparator<T> { a, b -> compareValuesBy(a, b, *selectors) }
}
class HomeFeed is here:
class HomeFeed(val standups: List<StandUps>)
and data class StandUps:
data class StandUps(
val artist: String,
val title: String,
val year: String,
val poster: String,
val description: String,
val netflix_link: String,
val imdb_rate: String,
val imdb_link: String,
val duration_min: String
)
It doesn't shows any errors or warnings, it just doesn't do anything. How could I achieve this?

You have to first store the sorted list in another variable and then use that variable to pass it to your adapter
val homeFeed = gson.fromJson(body, HomeFeed::class.java)
val sortedHomeFeed = homeFeed.standups.sortedWith(compareBy({it.year}))
runOnUiThread {
rv.adapter = Adapter(sortedHomeFeed)
}
The reason for this is, changes are not made to the original list following the concepts of immutability.

Kotlin gives you easy sorting. Jus like below
make a temp object (i.e)., tempFilterData here
val standUps = tempFilterData?.sortedWith(compareBy({ it.Year }))
Now you can get the sorted data based on YEAR

If you want to sort your list ascending by a year you can do this:
val sortedStandUps = homeFeed.standups.sortedBy { it.year }
If you want to sort list descending do this:
val sortedStandUps = homeFeed.standups.sortedByDescending { it.year }