Display data in recycler : Back4App / Kotlin

Android
1

I am new to Kotlin…I have no problem with the creation of a normal recyclerview with defined data, I just have a problem to inform my recycler with the data from back4App.
I don’t know if I built it correctly, but I got a “No value passed for parameter 'menuList” error. I don’t quite understand what is wrong. your help would be welcome.

my subclass
@ParseClassName(“MenuGeneral”)
open class PFmenuGeneral: ParseObject() {

var nom:String = "nom"

var menuGeneralList: String?
    get()=getString("nom")
    set(value) {
        if(value!=null) {
            put(nom,value)
        }
    }

fun getNom(block: (nom: List<PFmenuGeneral>?,exception: Exception?) -> Unit) {
    val query=ParseQuery.getQuery(PFmenuGeneral::class.java)
    query.orderByAscending("order")
    query.include("pointerPageVente")
    query.findInBackground { objects,error ->
        if(error==null) {
            for (nom in objects) {
                Log.d("DEBUG", nom.getString ("nom"))
            }
        } else {
            Log.d("item","Error: " + error!!.message)
        }
        block(objects, error)
    }
}

}

My Adapter

    class MenuGeneralAdapter(private val menuList: List<PFmenuGeneral> ): 
   RecyclerView.Adapter<MenuGeneralAdapter.MenuGeneralViewHolder>() {


   fun onMenuGeneralClick(index:Int, context:Context){
    val nomMenu: PFmenuGeneral = menuList[index]
   }
   override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MenuGeneralViewHolder {
    // 1 - chargement de la vue
    val rootView = LayoutInflater.from(parent.context).inflate(R.layout.cell_menugeneral,parent, 
    false)

    // 2 - création du view holder pour le contrôle de la vue
    val holder = MenuGeneralViewHolder(rootView)

    // 3 - retourner le view holder
    return holder
}
override fun onBindViewHolder(holder: MenuGeneralViewHolder,position: Int) {
    // 1 - obtenir la valeur(holder)

    val menuGeneral = menuList[position]

    //  2 - envoi des infos dans la cellule(position)
    holder.fillWithPFmenuGeneral(menuGeneral = menuGeneral)
}
override fun getItemCount(): Int {
    return menuList.size
}
inner class MenuGeneralViewHolder(rootView: View) : RecyclerView.ViewHolder(rootView),
    View.OnClickListener {
    private val ui_nom = rootView.ui_nom
    init {
        rootView.setOnClickListener(this)
    }
    fun fillWithPFmenuGeneral(menuGeneral: PFmenuGeneral){
        ui_nom.text = menuGeneral.nom
    }
    override fun onClick(v: View?) {
        if (v != null) {
            onMenuGeneralClick(adapterPosition, v.context)
        }
    }
}

}

My activity

     class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    val bottomNavigationView = findViewById<BottomNavigationView>(R.id.bottom_navigation)

    bottomNavigationView.selectedItemId = R.id.ic_home

    bottomNavigationView.setOnNavigationItemSelectedListener(BottomNavigationView.OnNavigationItemSelectedListener { menuItem ->
        when (menuItem.itemId) {
            R.id.ic_home -> return@OnNavigationItemSelectedListener true

            R.id.ic_convertisseur -> {
                startActivity(Intent(applicationContext, ConvertisseurActivity::class.java))
                overridePendingTransition(0, 0)
                return@OnNavigationItemSelectedListener true
            }

            R.id.ic_recherche -> {
                startActivity(Intent(applicationContext, SearchActivity::class.java))
                overridePendingTransition(0, 0)
                return@OnNavigationItemSelectedListener true
            }
            R.id.ic_favoris -> {
                startActivity(Intent(applicationContext,FavoritesActivity::class.java))
                overridePendingTransition(0, 0)
                return@OnNavigationItemSelectedListener true
            }
            R.id.ic_plus -> {
                startActivity(Intent(applicationContext, MoreActivity::class.java))
                overridePendingTransition(0, 0)
                return@OnNavigationItemSelectedListener true
            }
        }
        false
    })



      ui_menugenerallist.adapter = MenuGeneralAdapter()
      ui_menugenerallist.layoutManager = LinearLayoutManager(this)

}

fun openDecouverteButtonTouched(button: View){
    val intent = Intent(this, DecouverteActivity::class.java)
    startActivity(intent)
}

fun openSommaireButtonTouched(button: View){
    val intent = Intent(this, SommaireActivity::class.java)
    startActivity(intent)
}

}

2

You need to pass a value of menuList to this constructor. Or you could set a default parameter for the constructor like this

class MenuGeneralAdapter(private val menuList: List<PFmenuGeneral> = mutableListOf())
3

Thanks for your feedback, sorry but I don’t understand your advice