Investigating annotations in Godot 4

In this recipe, we will first look at @export and some of the variations associated with that annotation and then show how to use @onready.

Getting ready

For this recipe, open Godot 4 and start a new project called Chapter 2.

How to do it…

To investigate annotations, we will use each in a script by doing the following:

1. Open a new project in Godot.
2. In the Scene tab, click 2D Scene.
3. Click on the paper icon above Node2D and to the right of the filter Search box or in the Inspector tab under Node | Script. Click <empty>, then select New Script, and name the script Annotations.
4. Click on Script at the top of the editor to look at the new script we added.
5. @export is the same as export in Godot 3.x, so we will add a score to the node so we can see it in the Inspector tab:

   1  extends Node2D                           
   2     
   3  @export var score = 0

6. As you saw from the auto-completion, there are new @export options available now. Let’s add @export_range() to line 4:

   4  @export_range(0, 100, .1) var input_range

Note

This gives a range from 0 to 100 in increments of .1 to the input_range variable, which you can change in the Inspector tab.

7. We can show named enum values in the Inspector tab by adding the following to lines 5 and 6:

                                                         
   5    enum WeatherEnum {Sunny, Rainy, Cloudy = -1}
                                                      
   6    @export var weather: WeatherEnum

8. On line 7, let’s add a file to show up on the Inspector tab using @export_file:

   7    @export_file("*.txt") var file

9. Click on Node2D in the Scene tab. Then, click on + under Scene in the Scene tab to bring up the Create New Node window.
10. Then, type camer2d in the Search box. Select and add Camera2D to Node2D.
11. The onready keyword is now @onready. We will add a Camera2D node and use @onready with the camera on line 7:

    8    @onready var camera = $Camera2d

12. Click on Node2D at the top of the tree in the Scene tab to see everything we used with @export in the Inspector tab.

Figure 2.1 – Annotations.gd

How it works…

We added a score variable so we can could see it in the Inspector tab using @export instead of the export keyword.

We added @export_range(0, 100, .1) var input_range to show a range of 0 to 100 that snapped the value in .10 increments. You could also just use @export_range (0, 100) var input_range or @export_range (0, 100) var input_range: float.

We created an enum and then we used @export var weather: WeatherEnum to put the enum into the weather variable so we could see it in the Inspector tab. You could also do @export_enum(Sunny, Rainy, Cloudy) var weather.

We used the @export_file("*.txt") var file to show how a file is seen in the Inspector tab.

We added a Camera2D node to Node2D so we could use @onready with it. First, we just used @onready var camera = $Camera2d to add the Camera2D node to the camera variable.