Custom resources

Custom Resources are exposed to the end user to use within their development. Resources can store data that is easily edited from within the editor GUI. For example, you can create a custom AudioStream type that handles a new and interesting audio file type.

Registering a Resource

This workflow is similar to the Hello World example:

#![allow(unused)]
fn main() {
#[derive(GodotClass)]
#[class(init, base=Resource)]
struct ResourceType {
    base: Base<Resource>,
}
}

The above resource does not export any variables. While not all resources require exported variables, most do.

To execute code within the Godot Editor (e.g., overriding set_property to run custom logic when editing Inspector properties), you should annotate the class with #[class(tool)].

#![allow(unused)]
fn main() {
#[derive(GodotClass)]
#[class(tool, init, base=Resource)]
struct ResourceType {
    base: Base<Resource>,
}

#[godot_api]
impl IResource for ResourceType {
    // String representation of the object.
    fn to_string(&self) -> GString { ... }

    // Called when the object receives a Godot notification.
    fn on_notification(&mut self, what: ObjectNotification) { ... }

    // Called whenever get() is called or Godot gets the value of a property.
    fn get_property(&self, property: StringName) -> Option<Variant> { ... }

    // Called whenever Godot set() is called or Godot sets the value of a property.
    fn set_property(&mut self, property: StringName, value: Variant) -> bool { ... }

    // Called whenever Godot get_property_list() is called,
    // the returned vector here is appended to the existing list of properties.
    fn get_property_list(&mut self) -> Vec<PropertyInfo> { ... }

    // Called whenever Godot retrieves value of property. Allows to customize existing properties.
    // Every property info goes through this method, except properties added with get_property_list().
    fn validate_property(&self, property: &mut PropertyInfo) { ... }

    // Called by Godot to tell if a property has a custom revert or not.
    fn property_get_revert(&self, property: StringName) -> Option<Variant> { ... }

    fn setup_local_to_scene(&mut self) { ... }
}

}

It is important that similar to defining custom resources in GDScript, marking this class as a "tool class" is required to be usable within the editor.

The systems for registering functions, properties, and more are described in detail in the Registering Rust symbols section.