J-Custom_Extensions

A Godot plugin that simplifies the process of creating custom resource file types in Godot. Instead of relying on standard .tres (text) or .res (binary) formats, you can define your own custom extensions and associate them with your resource classes.

Installation

1. Copy the addons folder into your project.
2. In the Godot editor, go to Project → Project Settings → Plugins and enable J-Custom_Extensions.

Defining Custom Extensions

To register a custom extension for a resource class, add a constant to your class definition:

Minimal Example

extends Resource
class_name MyCustomResource

const tresCustom = "mcr"  # Custom alternative "tres" extension
const binaryCustom = "mcrb"  # Custom alternative "res" extension

@export var data: String = "example"
@export var value: int = 0

Notes:

• Do not include the dot when defining tresCustom or binaryCustom.
• Any Resources that are extensions of ones with defined custom extensions will also inherit them.
• Custom extensions do work in exported projects.

Refreshing Extensions

If you add or modify custom extensions in your classes they will need to be refreshed, this is done automatically when the engine is restarted but can also be done manually:

1. Go to Tools → Refresh Custom Extensions in the Godot editor
2. Or call build_map() on the extension mapper at runtime

How It Works

Architecture

The plugin consists of three main components:

1. main.gd - The plugin entry point that manages the editor integration
2. extension_mapper.gd - Scans project classes and maintains extension mappings
3. save_loader.gd - Implements custom ResourceFormatLoader and ResourceFormatSaver

Requirements

• Godot 4.0+
• Custom resource classes must be globally registered (using class_name)

License

See LICENSE

Support & Troubleshooting

Extensions Not Loading

• Ensure your class has class_name defined
• Verify the constant name is exactly tresCustom or binaryCustom
• Try refreshing extensions via Tools → Refresh Custom Extensions

Custom Loader/Saver Not Recognized

• Check that the extension mapping file exists at res://addons/J-Custom_Extensions/extension_map.tres
• Restart the editor or refresh custom extensions via Tools → Refresh Custom Extensions if the file is corrupted

Runtime vs Editor Differences

• In the editor, the plugin dynamically manages the loader/saver
• At runtime, an autoloaded instance handles all custom extension operations
• Extension mappings are persistent and loaded automatically