How to access the variable of a parent's script?

Question

I realize this question has been asked, but I've tried all of the solutions I can find to no avail. I'm wondering if there is something about my circumstances that is causing the issue. I have a fire particle effect that gets instantiated on an object as it's child, and then attempts to lower the health variable of it's parent. I've tried the following code:

 gameObject.transform.parent.GetComponent(EnemyData).health -= 3;

and

 transform.parent.GetComponent(EnemyData).health -= 3;

and

 gameObject.transform.parent.gameObject.GetComponent(EnemyData).health -= 3;

etc

Answer 1

Answer by aldonaletto · Aug 14, 2013 at 01:23 AM

You could simply use the second alternative:

 transform.parent.GetComponent(EnemyData).health -= 3;

But since you're getting null reference errors, either the object has no parent or its parent has no EnemyData script - if health was misspelled, the error would be different (something like health is not part of EnemyData or similar). Double check the hierarchy, or add debug lines to know what's happening:

 var daddy: Transform = transform.parent;
 if (!daddy) print("Object has no parent");
 var script: EnemyData = daddy.GetComponent(EnemyData);
 if (!script) print("Parent has no EnemyData script");
 script.health -= 3;

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Zodd · Aug 14, 2013 at 02:16 AM 0

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I think I might know what the problem is. The object is instantiated with a script on it that subtracts the health and whatnot, and then on the parent object's script it sets the instantiated object as it's child on the line right after it's instantiated. So the awake functions on the child are being triggered before it is set as the child to the parent object. Is there any way to instantiate it AS the child?

Zodd · Aug 14, 2013 at 02:22 AM 0

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I suppose worst case scenario I can just control it all with booleans, but instantiating it as a child would be less code.

aldonaletto · Aug 17, 2013 at 01:11 PM 0

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You could move the code related to the parent from Awake to Start: Awake is called when the object is created (before Instantiate returns, I believe), while Start executes some time after, after the calling routine that created the object has finished.

How to access the variable of a parent's script?

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