Recycle view inside not Showing in box layout - Kivy - python-3.x

Question

I have this code below - working on some kind of online streaming app.
My aim is to make the recycler view item occupy 90% while my top navigation takes 10%.
what I have done is put both in a box layout but the recycler view item seem to dissappear. I dont get errors but just a blank screen in the place where the recycler view item is supposed to show.
what Im I doing wrong
Thank you for your help
py
import os
from kivymd.app import MDApp
from kivy.uix.boxlayout import BoxLayout
from kivymd.uix.list import OneLineListItem, OneLineRightIconListItem, OneLineAvatarIconListItem, OneLineAvatarListItem, IRightBodyTouch
from kivymd.uix.gridlayout import MDGridLayout
from kivymd.uix.button import MDFlatButton, MDRectangleFlatButton, MDRaisedButton
from kivymd.uix.boxlayout import MDBoxLayout
from kivy.uix.recycleview import RecycleView
from kivy.uix.popup import Popup
from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.uix.screen import MDScreen
from kivy.properties import StringProperty
from pathlib import Path, PurePath
# Music Path
storageLocation = Path.cwd()
if Path('Books').is_dir():
storageLocation = Path.cwd() / 'Books'
# Check if file is in SD card
# elif Path.is_mount():
else:
storageLocation = Path.cwd() / 'Books'
storageLocation.mkdir()
class RecycleViewRow(BoxLayout):
text = StringProperty()
class MainScreen(MDScreen):
def __init__(self, **kwargs):
super(MainScreen, self).__init__(**kwargs)
booksdir = [f for f in storageLocation.iterdir() if f.is_dir()]
self.children[0].data = [{'text': str(x), 'id': str(x)} for x in booksdir]
self.theFiles = [self.children[0].data]
return
class Playlist(MDScreen):
def on_enter(self, *args):
return
class Main(MDApp):
def build(self):
self.theme_cls.theme_style = "Dark"
sm = ScreenManager()
sm.add_widget(MainScreen(name='MainScreen'))
sm.add_widget(Playlist(name='Playlist'))
sm.add_widget(Test(name="Test"))
return sm
def fill_playlist(self, dir):
self.root.current = 'Playlist' # this also clears the play list
playlist = self.root.get_screen('Playlist')
for sub in os.listdir(dir):
playlist.ids.Box.add_widget(OneLineAvatarIconListItem(text=sub))
Kivy
<RecycleViewRow>:
orientation: 'vertical'
OneLineAvatarIconListItem:
text: root.text
#on_press: app.root.message_box(root.text)
#on_release:app.root.current = 'Playlist'
on_release: app.fill_playlist(root.text)
Container:
id: container
MDIconButton:
icon: "download"
<MainScreen>:
MDBoxLayout
orientation:'horizontal'
MDToolbar:
title: 'Books'
left_action_items: [['menu', lambda x: x]]
right_action_items: [['dots-vertical', lambda x: x]]
MDBoxLayout
RecycleView:
id: rv
viewclass: 'RecycleViewRow'
spacing: 40
padding:10, 10
RecycleBoxLayout:
default_size: None, dp(56)
default_size_hint: 1, None
size_hint_y: None
height: self.minimum_height
orientation: 'vertical'
<Playlist>
MDBoxLayout:
orientation:'vertical'
spacing: 5
size_hint_y: None
height: self.minimum_height
MDList:
id:Box

Answer 1

The main issue with your code is the line:
self.children[0].data = [{'text': str(x), 'id': str(x)} for x in booksdir]
because self.children[0] in the MainScreen class is the MDBoxLayout. You should set the data for the RecycleView class, which has an id of rv. So that line should be:
self.ids.rv.data = [{'text': str(x), 'id': str(x)} for x in booksdir]
However, that won't work inside the __init__() method of MainScreen, bcause the ids have not yet been assigned at that point. Here is an approach that handles both those issues:
class MainScreen(MDScreen):
def __init__(self, **kwargs):
super(MainScreen, self).__init__(**kwargs)
Clock.schedule_once(self.build_rv)
def build_rv(self, dt):
booksdir = [f for f in storageLocation.iterdir() if f.is_dir()]
self.ids.rv.data = [{'text': str(x), 'id': str(x)} for x in booksdir]
self.theFiles = [self.ids.rv.data]
By delaying the execution of build_rv() with Clock.schedule_once(), the ids are available.