Allow editor to show children of custom class, tool scripts that add child nodes on _ready()

[data-overflow]

Hi! So I'm working at an app with Godot that heavily requires the use of UI. Almost all my UI elements require margins, paddings, panels or layout to so make things easier I wanted to create a node that stacks all these functions together into a single node.

I want a node which can do this to make my development time faster and reduce the complexity of my deeply nested scene tree.

So my approach was to create a script (extends MarginContainer for margin) with the class_name and tool keyword so that it shows up in the nodes list and allows me to preview the changes live on the editor. On the _ready() function, I'm adding a Panel and a MarginContainer as its child (for padding). The margins work as expected -

Any children I add to this node via the editor makes it its immediate children only. But now for the padding to work I need the nodes I add to this to automatically move to be the children of the MarginContainer instead. I did this using the following script -

func _ready():
	create_nodes()
	set_properties()
	connect("child_entered_tree", _on_child_entered_tree)
		
func create_nodes():
	padding_container = MarginContainer.new()
	panel = Panel.new()
	add_child(panel)
	panel.add_child(padding_container)

func set_properties():
	add_theme_constant_override("margin_top", margin_top)
	add_theme_constant_override("margin_bottom", margin_bottom)
	add_theme_constant_override("margin_left", margin_left)
	add_theme_constant_override("margin_right", margin_right)
	padding_container.add_theme_constant_override("margin_top", padding_top)
	padding_container.add_theme_constant_override("margin_bottom", padding_bottom)
	padding_container.add_theme_constant_override("margin_left", padding_left)
	padding_container.add_theme_constant_override("margin_right", padding_right)
	
func _process(delta):
	if Engine.is_editor_hint():
		set_properties()
		
func _on_child_entered_tree(node):
	remove_child(node)
	padding_container.add_child(node)

But then I faced a new problem. When I add nodes to my Div (custom node) it immediately becomes the child of the MarginContainer but also makes it inaccessible from the editor.

Error Log

Attempt to disconnect a nonexistent connection from 'Label:<Label#4244467947210>'. Signal: 'size_flags_changed', callable: 'Container::queue_sort'.
  Attempt to disconnect a nonexistent connection from 'Label:<Label#4244467947210>'. Signal: 'minimum_size_changed', callable: 'Container::_child_minsize_changed'.
  Attempt to disconnect a nonexistent connection from 'Label:<Label#4244467947210>'. Signal: 'visibility_changed', callable: 'Container::_child_minsize_changed'.

Is it possible to include this feature to show editor added children nodes to tool scripts?

[theraot]

If you set their owner after adding them to the scene tree, they should show up in the editor and also be saved with the scene.

About the signals in the error log you show... I do not know.

At least I can tell you that in tool scripts I'm used to check if a signal is connected before conecting it, and the equivalent for disconnection, that is because the signal connections would also get saved.