OnTriggerEnter through a different object

WHat I'm trying to do, is access one object's onTriggerEnter via the script on a second object. I've tried it as follows:

    touchRange.OnTriggerEnter(Collider coll) {

        if (coll.gameObject.name == "Player") {
            playerCollision = true;
            itemScript.curTouchedItem = itemName;


Where touchRange is an empty gameObject with a boxCollider (as trigger) that is a child of the object this script is attached to.

I hope it's not too vague ^^

You can't do what you want to do, directly. However, you can have OnTriggerEnter trigger an event, and have other classes listen for that event. This will yield better data encapsulation over what you are doing now.

Put this script on the game object with the collider:

public delegate void EventHandler ();
public event EventHandler CollideWithPlayer;

// Checking a reference to a collider is better than using strings.
[SerializeField] Collider playerCollider;

void OnTriggerEnter (Collider collider) {
    if (collider == playerCollider) CollideWithPlayer();

And on the parent object, you can use this:

bool playerCollision;
void Awake () {
    touchRange.CollideWithPlayer += () => playerCollision = true;       

itemScript.this and itemScript.that are not things you want to do. Instead, listen to the CollideWithPlayer event in ItemScript, directly, so things happening in ItemScript are more self-contained.

for those who still need this you can do this.

on the parent (weapon holder) script you can create a method like this. the method will take a collider and then we can assign it to anything.

 public class WeaponsController : MonoBehaviour
 //we would drag and drop the weapon in the inspector
 public GameObject weapon;
 private float Damage;
 private Collider EnemyCollider;  
 private bool enemyHit;
      public void Start()
            //on our weapon we may have a script called  "Sword" that contains all of the sword 
            //information, such as "Damage"
            Damage = weapon.GetComponent<Sword>().Damage;
     public void EnemyHit(Collider other)
             EnemyCollider = other;
             //if we have a health script on our enemy we may want to damage the enemy
             //so lets say we have a health script
             //we could call the take damage function on the enemy 
             //that was hit
             Debug.Log("Enemy Hit");
             enemyHit = true;
             // here we can take the collider that our weapon has sent us and we can assign
             // it to a new variable so that we can make any changes.

then on the weapon you can create a script and do this. you can check for collision and then call the function from your parent script and use the collider that was detected as the collider in the method you created.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 public class WeaponCollisionDetection : MonoBehaviour
    public WeaponsController WC;
    public void OnTriggerEnter(Collider other) 
     if (other.transform.tag == "Enemy")

Try to use UnityEvents. It’s simple, and by making them public, you can expose them in the editor to make it easy for other methods to subscribe for it.

using UnityEngine;
using UnityEngine.Events;

public class RangeTrigger()
     // You can subscribe other scripts' methods for the event.
     // The event will be exposed in the editor.
     // When it invokes, it will call all subscribed methods.
     public UnityEvent somethingGotInTheBoxCollider;

     private void OnTriggerEnter(Collider col)