Class transform "null" keyword error.

Questions & Answers
1

If my class is attachet to an object and extends Monobehaviour and set a transform from another script from another object I always get the “You are trying to create a MonoBehaviour using the new keyword.This is not allowed” warning…any clues on how to solve this ? the scripts actually work but I want to know what the warning means and what side effects it has.

the class script

#pragma strict

class aClass extends MonoBehaviour
{

var pos : Transform;


function aClass(a : Transform)
{
	pos = a;
}

function Updater()
{
	if(pos != null)
	{
		Debug.DrawRay(pos.position,Vector3(0,10,0), Color.red);
		print("abba");
	}
}

}

and the second script

#pragma strict

var grid : aClass;

function Start ()
{

grid =  aClass(gameObject.transform);

}
function Update()
{
grid.Updater();
}

the warning appears because the transform in the second script and points at the constructor in the class script.

2

In unity, don’t use class constructors unless you are developing an editor extensions. Always put your initialization code into Start event. If you need parameters for initialization, then write an init method with the parameter and call that method after you create the object. It should be something like that (C#)…

var object = (GameObject)Instantiate(<The prefab object you want to create>);
grid = object.GetComponent<aClass>();
if (grid) grid.Init(gameObject.transform);

— BUT —

If you want to create and use your own class just like a regular class (you won’t attach it to any gameobject in the inspector or in the code) … you shouldn’t extend it from MonoBehaviour.

In that case, just remove the “extend MonoBehaviour” part from your code and it’s ready to go.