Example use mvvm with recyclerview

activity_sample.xml

<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="viewModel"
            type=".SampleViewModel" />
    </data>

           <android.support.v7.widget.RecyclerView
                android:id="@+id/recyclerView"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                tools:itemCount="3"
                tools:listitem="@layout/list_item_posts"
                app:layoutManager="android.support.v7.widget.LinearLayoutManager"
                app:data="@{viewModel.posts}"/>

</layout>

BindableAdapter.kt

interface BindableAdapter<T> {
    fun setData(items: List<T>?)
}

BindingAdapters.kt

package br.com.youse.shared.binding.adapter

import android.animation.Animator
import android.animation.AnimatorListenerAdapter
import android.databinding.BindingAdapter
import android.support.annotation.ColorRes
import android.support.annotation.DrawableRes
import android.support.design.widget.TextInputLayout
import android.support.v4.content.ContextCompat
import android.support.v7.widget.RecyclerView
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import br.com.youse.shared.R
import br.com.youse.shared.presentation.adapter.BindableAdapter

object BindingAdapters {

    @BindingAdapter("data")
    @JvmStatic
    @Suppress("UNCHECKED_CAST")
    fun <T> setRecyclerViewProperties(recyclerView: RecyclerView, items: List<T>?) {
        if (recyclerView.adapter is BindableAdapter<*>) {
            (recyclerView.adapter as BindableAdapter<T>).setData(items)
        }
    }
}

list_item_posts.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="post"
            type="br.com.sample.model.PostUIModel" />

    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="@dimen/base"
        android:orientation="vertical">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@{post.title}" />

    </LinearLayout>
</layout>

SampleActivity.kt

class SampleActivity {

    public override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setupAdapters()
    }

    private fun setupAdapters() {
        val adapter = SimpleAdapter()
        recyclerViewBeneficiary.adapter = adapter
    }
}

SimpleAdapter.kt

class SimpleAdapter : RecyclerView.Adapter<
        SimpleAdapter.BeneficiaryViewHolder>(),
        BindableAdapter<PostUIModel> {

    inner class SimpleAdapter(val binding: ListItemPostsBinding) : RecyclerView.ViewHolder(binding.root)

    override fun setData(items: List<PostUIModel>?) {
        posts = items ?: emptyList()
        notifyDataSetChanged()
    }

    private var posts = emptyList<PostUIModel>()

    private var layoutInflater: LayoutInflater? = null

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BeneficiaryViewHolder {
        if (layoutInflater == null) {
            layoutInflater = LayoutInflater.from(parent.context)
        }

        val binding = DataBindingUtil.inflate<ViewDataBinding>(layoutInflater!!,
                R.layout.list_item_posts,
                parent, false) as ListItemPostsBinding

        return BeneficiaryViewHolder(binding)
    }
    override fun getItemCount() = posts.size

    override fun onBindViewHolder(holder: BeneficiaryViewHolder, position: Int) {
        holder.binding.post = posts[position]
    }

}