Followed the "Making main screen plugins" Tutorial however the buttons do not trigger a "pressed" signal

Question

I spent a good amount of time troubleshooting this however I cannot seem to figure it out.

Here is my code. It is a very close match with the "Making main screen plugins" Tutorial as I was trying to make a plugin,however I added a few debug statements.

Here is the code:
main_panel.gd

extends Panel

signal main_button_pressed(value)

func _ready():
    print("Debug 4")
    $Button.connect("pressed", self, "on_Button_pressed")

func on_Button_pressed():
    print("Debug 5")
    emit_signal("main_button_pressed", "Hello from main screen!")

func _on_side_button_pressed(value):
    print(value)
    $Label.text = value

side_panel.gd

extends Panel

signal side_button_pressed(value)

func _ready():
    print("Debug 2")
    $Button.connect("pressed", self, "on_Button_pressed")

func _on_Button_pressed():
    print("Debug 3")
    emit_signal("side_button_pressed", "Hello from side panel!")

func _on_main_button_pressed(value):
    print(value)
    $Label.text = value

mainscreenplugin.gd

tool
extends EditorPlugin

const MainPanel = preload("res://addons/theme_maker/scenes/main_panel.tscn")
const SidePanel = preload("res://addons/theme_maker/scenes/side_panel.tscn")

var main_panel_instance
var side_panel_instance

func _enter_tree():
    main_panel_instance = MainPanel.instance()
    side_panel_instance = SidePanel.instance()

    get_editor_interface().get_editor_viewport().add_child(main_panel_instance)

    add_control_to_dock(DOCK_SLOT_RIGHT_UR, side_panel_instance)

    make_visible(false)

func _exit_tree():
    main_panel_instance.queue_free()
    side_panel_instance.queue_free()

func _ready():
    print("Debug 1")
    main_panel_instance.connect("main_button_pressed", side_panel_instance, "_on_main_button_pressed")
    side_panel_instance.connect("side_button_pressed", main_panel_instance, "_on_side_button_pressed")

    main_panel_instance.emit_signal("main_button_pressed", "Hello 1")
    side_panel_instance.emit_signal("side_button_pressed", "Hello 2")

func has_main_screen():
    return true

func make_visible(visible):
    if visible:
        main_panel_instance.show()
    else:
        main_panel_instance.hide()

func get_plugin_name():
    return "Theme Maker"

This is the debug output when activating the plugin

Debug 1
 core/object.cpp:1238 - Error calling method from signal 'main_button_pressed': 'Panel(side_panel.gd)::_on_main_button_pressed': Method not found.
 core/object.cpp:1238 - Error calling method from signal 'side_button_pressed': 'Panel(main_panel.gd)::_on_side_button_pressed': Method not found.

No debug statements are printed when pressing either button

This is the scene tree for both Side and Main Panels (Same structure, different scenes)
- Panel
- - Button
- - Label

I simply don't know what is going wrong.
It seems like the buttons are not initialized properly or not connected. I tried manually connecting signals as well with no results.

Any help would be much appreciated. Thank you.

Comments

In side_panel.gd, you have a typo while defining your signal callback. I would also prefix underscores to all signal callbacks. Usually, they're private and don't need to be shown to the world.

I'd also add a little more detail to the rubber-duck statements. It's easier to follow.

---

Thanks. I fixed that typo and made both callbacks private.

---

For clarification I expect the starting output to be:

Debug 1
Debug 4
Debug 2

This is the ready function being called in all three scripts.

And then another debug statement whenever a button is pressed.