'Kotlin filter Search EditText in RecyclerView

In my android app Api 28 with Kotlin, I create an Interface "listOfCountry.xml", an editText for search and a recycler view that contains all the list of country as the following code:

           <EditText
                android:id="@+id/search"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="10dp"
                android:padding="5dp"
                android:layout_weight="1"
                android:background="@android:color/transparent"
                android:fontFamily="@font/cairo"
                android:hint="Search..."
                android:imeOptions="actionSearch"
                android:maxLines="1"
                android:singleLine="true"
                android:textSize="14sp"/>

    <TextView
        android:id="@+id/cancelSearch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:fontFamily="@font/cairo"
        android:layout_marginTop="15dp"
        android:layout_marginStart="20dp"
        android:text="@string/cancel_msg"
        android:textSize="14sp" />

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerViewGovernmentOrSectionList"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:layout_marginStart="20dp"
    android:layout_marginEnd="20dp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/lyt_search" />

I want to get a country from the list with the search filter, the following code is the description of my adapter :

class CountryItemAdapter(var countries: Array<AddressesData>, var mListener: OnItemClickListener) : RecyclerView.Adapter<CountryItemAdapter.ViewHolder>()
        , Filterable {

    private var selectedPos = -1
    var searchableList: MutableList<AddressesData> = arrayListOf()
    private var onNothingFound: (() -> Unit)? = null


    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.item_country, parent, false)
        return ViewHolder(view)
    }
    override fun getItemCount() = countries.size

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val item: AddressesData = countries[position]
        holder.tickImage.visibility = (if (selectedPos == position) View.VISIBLE else View.GONE)
        holder.country.text = item.englishName.toString()

        holder.itemView.setOnClickListener {
            selectedPos = position
            mListener.onItemClick(holder.itemView, item)
            notifyDataSetChanged()
        }

    }

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val country: TextView = itemView.counrty
        val tickImage: ImageView = itemView.tickGovernment
    }

    interface OnItemClickListener {
        fun onItemClick(view: View, viewModel: AddressesData)
    }
    override fun getFilter(): Filter {
        return object : Filter() {
            private val filterResults = FilterResults()
            override fun performFiltering(constraint: CharSequence?): FilterResults {
                searchableList.clear()
                if (constraint.isNullOrBlank()) {
                    searchableList.addAll(countries)
                } else {
                    val filterPattern = constraint.toString().toLowerCase().trim { it <= ' ' }
                    for (item in 0..countries.size) {
                        if (countries[item].englishName!!.toLowerCase().contains(filterPattern)) {
                            searchableList.add(countries[item])
                        }
                    }}
                    return filterResults.also {
                        it.values = searchableList
                    }
                }

                override fun publishResults(constraint: CharSequence?, results: FilterResults?) {
                    if (searchableList.isNullOrEmpty())
                        onNothingFound?.invoke()
                    notifyDataSetChanged()

                }

and I add the following code in my activity :

search.addTextChangedListener(object : TextWatcher {
            override fun beforeTextChanged(charSequence: CharSequence, i: Int, i1: Int, i2: Int) {}
            override fun onTextChanged(charSequence: CharSequence, i: Int, i1: Int, i2: Int) {
                adapter.filter.filter(charSequence.toString())

            }

            override fun afterTextChanged(editable: Editable) {}
        })

The filter didn't work, I would like to know where's the problem in my code and How can I correct it to make the filter work ?

Solution 1:^[1]

I think you lost getItemCount method in your adapter, it must return actual size of items in adapter.

Solution 2:^[2]

Its late but may it it will help someone,

You are filtering data in searchableList list but you have applied countries list to adapter. Change accordingly it will work.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1	Yrii Borodkin
Solution 2	Amin Pinjari

'Kotlin filter Search EditText in RecyclerView

Solution 1:[1]

Solution 2:[2]

Sources

Related Questions

Solution 1:^[1]

Solution 2:^[2]