MDTextField missing HelperText

ikus060 commented 5 months ago

Description of the Bug

When creating MDTextField on the fly. The HelperText is not displayed.

Code and Logs

from kivy.clock import Clock
from kivy.lang import Builder

from kivymd.app import MDApp
from kivymd.uix.boxlayout import MDBoxLayout

KV = """
MDScreen:
    md_bg_color: self.theme_cls.backgroundColor

    MDBoxLayout:
        id: wrapper

        Component:

    MDBoxLayout:

        MDButton:
            on_release: app.add()

            MDButtonText:
                text: "Add"

<Component>:

    MDTextField:
        id: field
        pos_hint: {"center_x": .5, "center_y": .5}
        text: "Text"
        size_hint_x: .6
        name: "Hint text"

        MDTextFieldHelperText:
            text: "Helper text"
            mode: "persistent"

"""

class Component(MDBoxLayout):
    pass

class TestHelperTextModePersistent(MDApp):
    def build(self):
        return Builder.load_string(KV)

    def add(self):
        subview = Component()
        self.root.ids.wrapper.add_widget(subview)

TestHelperTextModePersistent().run()