How do I connect to a signal being emitted by a scene I am dynamically loading into a scene?

v33to

So I have dice.tscn (root node is called "dice") and it is preloaded in gameboard.tscn (gameboard.gd). When the dice are rolled I want the player to be able to click on them and I want to update a value in gameboard.gd.

I can't seem to figure out how to write the signal connection on gameboard.gd, do I need to connect to the signal of the scene? Or the dice node as it appears in the scene tree? The dice appear as dice, @dice@2, @dice@3 in the scene tree which makes it difficult to hard code the connections.

Bl4ckM4ch1n3

You can connect a signal after instancing the dice. I'm currently at work and I don't have a chance to try out the code myself. So I'm not 100% sure it works - but I guess it should =) Assuming your dice.gd script contains a signal (for example signal rolled)

gameboard.gd:

    var new_dice = dice_scene.instance()
   #add_child and position your stuff here
    new_dice .connect("rolled", self, "_on_dice_rolled")
    
    func _on_dice_rolled(argument):
    	#do stuff to update your value

dice.gd:

signal rolled
    
func _on_dice_clicked():
	var rolled_number = 123
	emit_signal("rolled", rolled_number)

v33to

@Bl4ckM4ch1n3 said: You can connect a signal after instancing the dice. I'm currently at work and I don't have a chance to try out the code myself. So I'm not 100% sure it works - but I guess it should =) Assuming your dice.gd script contains a signal (for example signal rolled)

gameboard.gd:
    var new_dice = dice_scene.instance()
   #add_child and position your stuff here
    new_dice .connect("rolled", self, "_on_dice_rolled")
    
    func _on_dice_rolled(argument):
    	#do stuff to update your value
dice.gd:
signal rolled
    
func _on_dice_clicked():
	var rolled_number = 123
	emit_signal("rolled", rolled_number)

Ahh ok, so I connect to the new instance of it. My next question, is there a way to just emit a signal to a global signal listener that I can use anywhere in the project? I'm guessing this would yeild to bad performance but it's a pretty low spec game and I don't think it would be an issue. Throughout the lifetime of a single game there will maybe 20-30 instances of the dice scene and so the name of them always changes.

Thank you btw.

Bl4ckM4ch1n3

@v33to said: Ahh ok, so I connect to the new instance of it. My next question, is there a way to just emit a signal to a global signal listener that I can use anywhere in the project? I'm guessing this would yeild to bad performance but it's a pretty low spec game and I don't think it would be an issue. Throughout the lifetime of a single game there will maybe 20-30 instances of the dice scene and so the name of them always changes.

Thank you btw.

Glad I could help! :) It depends on how you want to implement the global listener and which nodes/scenes should be listened to, I guess. Do you want to use a Singleton/AutoLoad script or a node which is always present within the root node?

v33to

@Bl4ckM4ch1n3 said:

@v33to said: Ahh ok, so I connect to the new instance of it. My next question, is there a way to just emit a signal to a global signal listener that I can use anywhere in the project? I'm guessing this would yeild to bad performance but it's a pretty low spec game and I don't think it would be an issue. Throughout the lifetime of a single game there will maybe 20-30 instances of the dice scene and so the name of them always changes.

Thank you btw.

Glad I could help! :) It depends on how you want to implement the global listener and which nodes/scenes should be listened to, I guess. Do you want to use a Singleton/AutoLoad script or a node which is always present within the root node?

I considered that, as a few Youtube tutorials I've been watching have been implementing similar things. But it actually seems a bit messier, because in the singleton/global script I'd have to connect the signal to a function in another script right?

Bl4ckM4ch1n3

That's a good question. I'm relatively new to Godot myself but I've got some experience working with Unity3D. What signal do you want to connect? Is the node that emits the signal instanced during runtime? If so, you could provide a function within your Singleton to connect to the signal.

Let's say you want to connect your global listener to the same "rolled" signal of your dice scene: Add the globallistener.gd script to the AutoLoad list within the project settings and name it "globallistener" or something similar (I'll stick with globallistener).

dice.gd

signal rolled

func _on_dice_clicked():
var rolled_number = 123
emit_signal("rolled", rolled_number)

gameboard.gd

var global_listener = get_node("/root/globallistener")
var new_dice = dice_scene.instance()
#add_child and position your stuff here
new_dice .connect("rolled", self, "_on_dice_rolled")
global_listener.connect_dice(new_dice, "rolled")

func _on_dice_rolled(argument):
#do stuff to update your value

globallistener.gd

func connect_dice(instanced_dice, signal_name):
	instanced_dice.connect(signal_name, self, "_on_dice_signal")

func _on_dice_signal(argument):
	#do stuff

This is just one possibility, of course. You could add various if-statements to the code, routing to different functions. For example:

gameboard.gd

var global_listener = get_node("/root/globallistener")
var new_dice = dice_scene.instance()
#add_child and position your stuff here
new_dice .connect("rolled", self)
global_listener.connect_dice(new_dice, "rolled")
global_listener.connect_dice(new_dice, "discarded")

func _on_dice_rolled(argument):
	#do stuff

globallistener.gd

func connect_dice(instanced_dice, signal_name):
	if signal_name == "rolled":
   		instanced_dice.connect(signal_name, self, "_on_dice_rolled")
    elif signal_name == "discarded":
    	instanced_dice.connect(signal_name, self, "_on_dice_discarded")

func _on_dice_rolled(argument):
	#do stuff

func _on_dice_discarded(argument):
	#do stuff

Again, the code is not tested as I'm at work. But I think there are a lot of possibilities to achieve your wanted behavior.

v33to

Thank you. I will make a sample project and fiddle with this, see if I like it. Cheers. GG.