Wren class does not implement a field - wren

Question

I'm trying to learn how to use Dome and Wren. To do this I've started working on a simple Flappy Bird clone.
The problem I'm having is that I get the error message
Bird does not implement bird_idle
It then points to line 63 in my main class which is shown below:
class Main {
resources=(value){ _resources = value }
bird=(value){ _bird = value }
construct new() {
_resources = Resources.new()
_bird = Bird.new(_resources.birdIdle, _resources.birdFlap, _resources.obstacleTile.width * 2, _resources.obstacleTile.height * 4, 10, 4)
}
init() {}
update() {}
draw(alpha) {
Canvas.cls()
Canvas.draw(_bird.bird_idle, _bird.center.x, _bird.center.y) <-- this is line 63
}
}
var Game = Main.new()
Since I'm new to Wren I don't quite understand what this means seeing as if you look at my bird class below, I should be implementing bird_idle. So what am I doing wrong?
class Bird {
bird_idle=(value){ _bird_idle = value } <-- Right?
bird_flap=(value){ _bird_flap = value }
center=(value){ _center = value }
gravity=(value){ _gravity = value }
force=(value){ _force = value }
velocity=(value){ _velocity = value }
velocityLimit=(value){ _velocityLimit = value }
isGameRunning=(value){ _isGameRunning = value }
construct new(idle, flap, horizontalPosition, verticalPosition, drag, jumpForce) {
_bird_idle = idle
_bird_flap = flap
_center = Vector.new(horizontalPosition + (idle.width * 0.5), verticalPosition + (idle.height*0.5))
_gravity = drag
_force = jumpForce
_velocityLimit = 1000
_isGameRunning = true
}
jump() {
_velocity = -_force
}
isTouchingCeiling() {
var birdTop = _center.y - (_bird_idle.height * 0.5)
if(birdTop < 0) {
return true
}
return false
}
isTouchingGround() {
var birdBottom = _center.y + (_bird_idle.height * 0.5)
if(birdBottom > height) {
return true
}
return false
}
}

Answer 1

You forgot to add the getter:
class Bird {
construct new(idle) {
_bird_idle = idle
}
bird_idle=(value){_bird_idle = value }
bird_idle{_bird_idle} // You need this if you want to access the field _bird_idle.
}
var my_bird = Bird.new("Idle")
my_bird.bird_idle = "Not Idle"
System.print(my_bird.bird_idle) // Output: Not Idle