Making plugins

About plugins

A plugin is a great way to extend the editor with useful tools. It can be made entirely with GDScript and standard scenes, without even reloading the editor. Unlike modules, you don't need to create C++ code nor recompile the engine. While this makes plugins less powerful, there are still many things you can do with them. Note that a plugin is similar to any scene you can already make, except it is created using a script to add editor functionality.

This tutorial will guide you through the creation of two plugins so you can understand how they work and be able to develop your own. The first is a custom node that you can add to any scene in the project, and the other is a custom dock added to the editor.

Creating a plugin

Before starting, create a new empty project wherever you want. This will serve as a base to develop and test the plugins.

The first thing you need for the editor to identify a new plugin is to create two files: a plugin.cfg for configuration and a tool script with the functionality. Plugins have a standard path like addons/plugin_name inside the project folder. Godot provides a dialog for generating those files and placing them where they need to be.

In the main toolbar, click the Project dropdown. Then click Project Settings.... Go to the Plugins tab and then click on the Create New Plugin button in the top-right.

You will see the dialog appear, like so:

../../../_images/making_plugins-create_plugin_dialog.webp

The placeholder text in each field describes how it affects the plugin's creation of the files and the config file's values.

To continue with the example, use the following values:

Plugin Name: My Custom Node
Subfolder: my_custom_node
Description: A custom node made to extend the Godot Engine.
Author: Your Name Here
Version: 1.0.0
Language: GDScript
Script Name: custom_node.gd
Activate now: No

Warning

Unchecking the Activate now? option in C# is always required because, like every other C# script, the EditorPlugin script needs to be compiled which requires building the project. After building the project the plugin can be enabled in the Plugins tab of Project Settings.

You should end up with a directory structure like this:

../../../_images/making_plugins-my_custom_mode_folder.webp

plugin.cfg is an INI file with metadata about your plugin. The name and description help people understand what it does. Your name helps you get properly credited for your work. The version number helps others know if they have an outdated version; if you are unsure on how to come up with the version number, check out Semantic Versioning. The main script file will instruct Godot what your plugin does in the editor once it is active.

The script file

Upon creation of the plugin, the dialog will automatically open the EditorPlugin script for you. The script has two requirements that you cannot change: it must be a @tool script, or else it will not load properly in the editor, and it must inherit from EditorPlugin.

Warning

In addition to the EditorPlugin script, any other GDScript that your plugin uses must also be a tool. Any GDScript without @tool imported into the editor will act like an empty file!

It's important to deal with initialization and clean-up of resources. A good practice is to use the virtual function _enter_tree() to initialize your plugin and _exit_tree() to clean it up. Thankfully, the dialog generates these callbacks for you. Your script should look something like this:

@tool
extends EditorPlugin


func _enter_tree():
    # Initialization of the plugin goes here.
    pass


func _exit_tree():
    # Clean-up of the plugin goes here.
    pass

This is a good template to use when creating new plugins.

A custom node

Sometimes you want a certain behavior in many nodes, such as a custom scene or control that can be reused. Instancing is helpful in a lot of cases, but sometimes it can be cumbersome, especially if you're using it in many projects. A good solution to this is to make a plugin that adds a node with a custom behavior.

Warning

Nodes added via an EditorPlugin are "CustomType" nodes. While they work with any scripting language, they have fewer features than the Script Class system. If you are writing GDScript or NativeScript, we recommend using Script Classes instead.

To create a new node type, you can use the function add_custom_type() from the EditorPlugin class. This function can add new types to the editor (nodes or resources). However, before you can create the type, you need a script that will act as the logic for the type. While that script doesn't have to use the @tool annotation, it can be added so the script runs in the editor.

For this tutorial, we'll create a button that prints a message when clicked. For that, we'll need a script that extends from Button. It could also extend BaseButton if you prefer:

@tool
extends Button


func _enter_tree():
    pressed.connect(clicked)


func clicked():
    print("You clicked me!")