TransformExtensions.cs

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public static class TransformExtensions
{
	static Stack<Transform> moveTargets = new Stack<Transform> ();	//This is only used by SetLayerToThisAndChildren
	
	public static void SetLayerToThisAndChildren (this Transform root, int layer)
	{
		moveTargets.Push (root);
		Transform currentTarget;
		while (moveTargets.Count != 0) {
			currentTarget = moveTargets.Pop ();
			currentTarget.gameObject.layer = layer; //.gameObject adds GC.
			int childCount = currentTarget.childCount;
			for (int i = 0; i < childCount; ++i)
				moveTargets.Push (currentTarget.GetChild (i)); //.GetChild(i) adds GC.
		}
		
	}

	public static string GetPath (this Transform t)
	{
		if (t.parent == null)
			return t.name;
		return t.parent.GetPath () + "/" + t.name;
	}

	public static T GetOrAddComponent<T> (this Component c) where T:Component
	{
		T instance = c.GetComponent<T> ();
		if (instance == null)
			instance = c.gameObject.AddComponent<T> ();
        
		return instance;
	}

	public static void SetTransformRectToPlayerCamera (this RectTransform rectTransform, Camera cam)
	{
		if (cam == null)
			return;
        
		var min = rectTransform.anchorMin;
		min.x = cam.rect.x;
		rectTransform.anchorMin = min;
		var max = rectTransform.anchorMax;
		max.x = rectTransform.anchorMin.x + cam.rect.width;
		rectTransform.anchorMax = max;
	}
}