Guide to the Godot game engine/Creating resources

To make a new Resource, you need to make a new script (that is not attached to a node). Here is an example:

<-- Making your first plugin Creating resources Importers-->

tool
extends Resource

export (int, INT, STRING) var property_type = 0 setget set_type
var property

func _get_property_list():
  var out = [
    {
       "name": "Property",
       "type": [TYPE_INT, TYPE_STRING][property_type]
    }
  ]
  return out

func _get(what):
  if what == "Property":
    return property

func _set(what, to):
  if what == "Property":
    what = to

func set_type(value):
  property_type = value
  match value:
    0:
       if !property is int:
         property = int(property)
    1:
       if !property is String:
         property = String(property)

A simple example that shows a resource that can store either an int or a String.

The _get_property_list() must return an Array of Dictionarys, each with the following values:

name (String): the property's name.
type (int): A constant that begins with TYPE_*.

The following are optional:

hint (int): PROPERTY_HINT_* constants.
hint_string (String)
usage (int): PROPERTY_USAGE_* constants.

property_type is too simple to need to be changed or defined with _get_property_list(). Instead, export is used, along with setget to process when it is changed.

When property_type is set, the type of property is changed.

Real-world examples include storing keys or images. A resource just holds data for other scripts, it doesn't actually process it itself.