How can I make two graph nodes automatically linked to eachother?

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1

Godot Version

4.6

Question

Hello

I am trying to create an undirected graph, that I can give neighbours in the Godot editor

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image250×166 5.77 KB

Here is the relevant code for a vertex :

@tool
class_name node_map
extends Area2D


@export var node_neighbours: Array[node_map] = []

I want, when clicking on the “Add Element” and setting another node to that element, to have the current node added in the neighbour of the selected one

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image438×102 6.1 KB

To use the example from Wikipedia, imagine if I add to the node 6 the node 4 as neighbour, the opposite happens ; the 4 adds 6 as neighbour

Note that I don’t want to have only graphic changes. The neighbours have a role in the gameplay

Thank you in advance

2

Typically you would use a setter function, but with array types it may not trigger. If it doesn’t then you can create an @export_tool_button to update the neighbours of your neighbours. Or handle a NOTIFICATION_EDITOR_PRE_SAVE notification via func _notification

3

You can connect to inspector’s property_edited signal. It should emit when an array is altered.

4

Ok, I didn’t know about EditorInspector, and it was a bit confusing for me, but I think I understand it

So, it’s only about the engine (and not a possible node), and adding an element in the array would trigger the signal, where the only thing I have to do now would be to do the connections when the signal is received. Am I right ?

5

Yes, you’d need to rebuild the graph connections in the signal handler.

6

Many thanks !