How to implement nested paging in android kotlin?

Question

I have a recyclerview , for i using pagin 3 with coroutine live data . but child recyclerview also have paginate data so how can i perform this nested pagination in android kotlin.

Answer 1

So , I done this with pagination for child recyclerview inside recyclerview . Firstly of all call api for fetch dates and perform api for every date at same time when date are fetching.

so structure like this...

lateinit var adapter: WeeklyAdapter
lateinit var dayAdapter: DayDetailsPagingAdapter


    private fun observeData() {
        viewModel.weeklyAcquiringDetails(AcquiringVM.WEEKLY, "").observe(this){
            wsWithLoader(it){
                binding.rvAcquiringWeeklyDetails.adapter = WeeklyAdapter(it.data!!.data, object : WeeklyAdapter.OnPerformApi{
                    override fun performApi(date: String, rvMonthly: RecyclerView) {
                        dayAdapter = DayDetailsPagingAdapter(object  : DayDetailsPagingAdapter.OnClick{
                            override fun onClick(result: DayAcquiring.Data) {}
                        })
                        rvMonthly.adapter = dayAdapter
                        lifecycleScope.launchWhenCreated {
                            viewModel.getDayAcquiringDetails(date).collectLatest { data ->
                                dayAdapter.submitData(data)
                            }
                        }
                    }
                })
            }
        }
    }

Weekly Adapter

class WeeklyAdapter (
        val list: List<WeeklyAcquiring.Data>,
        val action: OnPerformApi
    ) : RecyclerView.Adapter<WeeklyAdapter.ViewHolder>() {
    
        @NonNull
        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
            return ViewHolder(DataBindingUtil.inflate(LayoutInflater.from(parent.context), R.layout.list_monthly, parent, false))
        }
    
        override fun onBindViewHolder(holder: ViewHolder, position: Int) {
            val result = list[position]
            holder.binding.apply {
                tvDate.text = changeDateFormat(result.doctorScheduleDate,"yyyy-MM-dd","E, dd MMM yyyy")
                action.performApi( result.doctorScheduleDate , rvMonthly)
            }
        }
    
        override fun getItemCount(): Int {
            return list.size
        }
    
        inner class ViewHolder(binding: ListMonthlyBinding) : BaseViewHolder<ListMonthlyBinding>(binding) {}
    
        interface OnPerformApi{
            fun performApi(date : String, rvMonthly: RecyclerView)
        }
        }

list_monthly_layout

<?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>

    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:id="@+id/tvDate"
            style="@style/TVBold"
            android:layout_marginTop="@dimen/_5sdp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="@dimen/_12sdp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            tools:text="May 2022" />

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/rvMonthly"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/_10sdp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
            app:layout_constraintStart_toStartOf="parent"
            tools:listitem="@layout/list_acquiring_details"
            app:layout_constraintTop_toBottomOf="@+id/tvDate" />

    </androidx.constraintlayout.widget.ConstraintLayout>

</layout>

DayDetailsPagingAdapter

class DayDetailsPagingAdapter (private val onClick: OnClick) : PagingDataAdapter<DayAcquiring.Data, DayDetailsPagingAdapter.ViewHolder>(DiffCallback()) {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
    return ViewHolder(ListAcquiringDetailsBinding.inflate(LayoutInflater.from(parent.context), parent, false))
}

@SuppressLint("SetTextI18n")
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
    val result = getItem(position)!!
    holder.binding.apply {
        data = result
        tvName.text = result.userName
        tvAmount.text = "€ ${result.amount}"
    }
}

class ViewHolder(val binding: ListAcquiringDetailsBinding) : RecyclerView.ViewHolder(binding.root) {}

private class DiffCallback : DiffUtil.ItemCallback<DayAcquiring.Data>() {
    override fun areItemsTheSame(
        oldItem: DayAcquiring.Data,
        newItem: DayAcquiring.Data
    ): Boolean = oldItem == newItem

    override fun areContentsTheSame(
        oldItem: DayAcquiring.Data,
        newItem: DayAcquiring.Data
    ): Boolean = oldItem == newItem
}

interface OnClick {
    fun onClick(result: DayAcquiring.Data )
}
}

**in viewmodel **

fun getDayAcquiringDetails( date: String ) = apiHelper.getDayAcquiringDetails( date ).cachedIn(viewModelScope)
fun weeklyAcquiringDetails( filter: String ,  date: String) = apiHelper.weeklyAcquiringDetails( filter , date)

hope you like this .