I am in need of a little help with the latest version of Haxe/openFL.
When targeting a movie clip in openFL from a function I get the error unknown identifier. An example:
addChild(parentMC);
…
parentMC.addChild(childMC);
…
private function someFunction():Void{
trace(parentMC.childMC.x);
}
output:
Source/Main.hx:263: characters 2-18 : Unknown identifier : parentMC
I have also tried calling the child directly like so
childMC.x
but get the same type of error.
How do I get the property the child MC or even the parent from within a function?
using hate version:
3.2.1
Libraries:
actuate: [1.8.6]
air3: [0.0.1]
box2d: [1.2.3]
flambe: [4.1.0]
format: [3.2.1]
haxeui: [1.8.18]
hscript: [2.0.7]
hvm: [0.0.2]
hxcpp: [3.2.205]
hxsl: [2.0.5]
layout: [1.2.1]
lime-samples: [2.6.0]
lime: [2.9.1]
openfl-samples: [3.3.1]
openfl: [3.6.1]
swf: [2.2.0]
There are three types of variables: static, instance, and local.
class Main {
//Static variable.
public static var firstVar:Float = 1;
//Instance variable.
public var secondVar:Float = 2;
public function new() {
//Local variable.
var thirdVar:Float = 3;
//You can access a static variable anywhere.
trace(firstVar);
//You can access an instance variable from any
//non-static function in the class.
trace(secondVar);
//You can access a local variable in the same function.
trace(thirdVar);
}
public function exampleFunction():Void {
//You can still access static and instance variables.
trace(firstVar);
trace(secondVar);
//You CANNOT access local variables from a different function.
//This produces an error:
trace(thirdVar);
}
}
If you want to “remember” a local variable, turn it into an instance variable:
class Main {
private var thirdVar:Float;
public function new() {
//You can still access it from the constructor.
thirdVar = 3;
}
public function exampleFunction():Void {
//Now you can access it from this function too, because
//it's an instance variable.
trace(thirdVar);
}
}
Hi, thanks for the response but my issue is not getting a variable value but getting the properties of a movie clip from a function.
Back in actionscript I could get the the width,height, x position, y position by doing something like this:
trace(root.parentMC.childMC.x);
In openfl/haxe this is not the case. Documentation says to get a movie/sprite properties I have to do somethins like this:
getChildByName("childMC");
but this is returning a null value. How would I get these properties from a movie clip in stage/root from a function.
class Main extends Sprite {
public function new () {
super ();
var background = Assets.getBitmapData("assets/bg-scene.jpg");
var bitmap = new Bitmap (background);
var backgroundsMC: MovieClip = new MovieClip();
addChild(backgroundMC);
}
private function simplefunction():Void{
trace(backgroundsprite.width);
//this is where I am stuck I cannot get this property no matter how I write this code.
}
}
Update:
trace(this.backgroundMC.getChildAt(1));
trace(this.backgroundMC.getChildAt(1));
Both return
Source/Main.hx:125: characters 8-40 : openfl.display.DisplayObject cannot be called
childMC is not a property of parentMC, so ‘.’ is never going to work.
But you have to define your var outside of the ‘new’ function. As soon as it’s a class variable, you can access it in all your functions in this class. At the moment it’s local to function new…
This is exactly what I was telling you about. You’re creating a local variable (backgroundMC), and then trying to access it from a different function. If you want to access it, turn it into an instance variable:
class Main extends Sprite {
private var backgroundMC:MovieClip;
public function new () {
super ();
var background = Assets.getBitmapData("assets/bg-scene.jpg");
var bitmap = new Bitmap (background);
backgroundMC = new MovieClip();
addChild(backgroundMC);
}
private function simplefunction():Void{
trace(backgroundMC.width);
}
}
2 Likes
Thanks a lot for the info! You finally gave me the “a ha!” moment. I was approaching this from an actionscript 3 way of doing things. This is exactly the info I needed to make my app work! Thanks again for the info!
