Update text strip content, when changing text-block

__init__.py

import bpy

# Store the last synced text block content to detect changes
LAST_SYNCED_TEXT = {"content": None, "name": None}

# Add properties to the Text Strip
def add_text_strip_properties():
    bpy.types.Sequence.text_sync_enabled = bpy.props.BoolProperty(
        name="Sync with Text Block",
        description="Enable syncing with a specific text block",
        default=False,
        update=on_sync_toggle_update
    )
    bpy.types.Sequence.text_sync_text_block = bpy.props.PointerProperty(
        name="Text Block",
        type=bpy.types.Text,
        description="Select the text block to sync with this text strip",
        update=on_sync_toggle_update
    )

def remove_text_strip_properties():
    del bpy.types.Sequence.text_sync_enabled
    del bpy.types.Sequence.text_sync_text_block

def on_sync_toggle_update(self, context):
    """
    Callback for the on/off toggle to enable or disable syncing.
    """
    if self.text_sync_enabled:
        setup_text_block_timer()
        sync_text_strip()
    else:
        remove_text_block_timer()

def get_textblock_from_strip(strip):
    """
    Get the text block selected in the strip's custom property.
    """
    if strip and strip.text_sync_enabled and strip.text_sync_text_block:
        return strip.text_sync_text_block
    return None

def get_active_textstrip():
    """
    Retrieve the active text strip from the Video Sequence Editor.
    """
    sequence_editor = bpy.context.scene.sequence_editor
    if not sequence_editor:
        return None

    active_text_strip = sequence_editor.active_strip

    # Ensure the active strip is a text strip
    if not active_text_strip or active_text_strip.type != 'TEXT':
        return None

    return active_text_strip

def sync_text_strip():
    """
    Synchronize the content of the selected text block with the active text strip.
    """
    active_text_strip = get_active_textstrip()
    if not active_text_strip:
        return

    # Get the text block from the strip's property
    text_block = get_textblock_from_strip(active_text_strip)
    if not text_block:
        return

    # Update the text strip content with the text block content
    content = text_block.as_string()
    active_text_strip.text = content
    LAST_SYNCED_TEXT["content"] = content
    #LAST_SYNCED_TEXT["name"] = text_block.name

def check_text_block_update():
    """
    Check if the content of the selected text block has changed.
    If it has, synchronize it with the active text strip.
    """
    active_text_strip = get_active_textstrip()
    if not active_text_strip or not active_text_strip.text_sync_enabled:
        return None

    # Get the selected text block
    text_block = get_textblock_from_strip(active_text_strip)
    if not text_block:
        return None
    
    if text_block.name != LAST_SYNCED_TEXT["name"]:
        return None

    # Compare the current content with the last synced content
    current_content = text_block.as_string()
    if current_content != LAST_SYNCED_TEXT["content"]:
        sync_text_strip()

    # Continue checking every 1 second
    return 1.0

def setup_text_block_timer():
    """
    Set up a timer to periodically check if the text block has changed.
    """
    if not bpy.app.timers.is_registered(check_text_block_update):
        bpy.app.timers.register(check_text_block_update, first_interval=1.0)

def remove_text_block_timer():
    """
    Remove the timer that checks for text block updates.
    """
    if bpy.app.timers.is_registered(check_text_block_update):
        bpy.app.timers.unregister(check_text_block_update)

# Extend the SEQUENCER_PT_effect Panel
def draw_sync_ui(self, context):
    layout = self.layout
    strip = context.scene.sequence_editor.active_strip

    if strip and strip.type == 'TEXT':
        
        # Create a row for the toggle and the text-block selector
        row = layout.row(align=True, heading="")
        row.use_property_decorate = False

        # Add the toggle button
        sub = row.row(align=True)
        sub.prop(strip, "text_sync_enabled", text="")

        # Add the text-block selector, activating only if the toggle is enabled
        subsub = sub.row(align=True)
        subsub.active = strip.text_sync_enabled
        subsub.prop(strip, "text_sync_text_block", text="")
        
        # Optional decorator (useful for UI consistency and showing relationships)
        row.prop_decorator(strip, "text_sync_text_block")

def prepend_sync_ui():
    bpy.types.SEQUENCER_PT_effect.prepend(draw_sync_ui)

def remove_sync_ui():
    bpy.types.SEQUENCER_PT_effect.remove(draw_sync_ui)

# Registration
def register():
    """
    Register the script's functionality.
    """
    add_text_strip_properties()
    prepend_sync_ui()

def unregister():
    """
    Unregister the script's functionality.
    """
    remove_text_strip_properties()
    remove_sync_ui()
    remove_text_block_timer()

if __name__ == "__main__":
    register()