Custom Inspector: Accessing a reference to another MonoBehaviour?

Questions & Answers
1

Hello.

I have two Monobehaviours, one is a Path, the other a Path Follower.
The Path Follower has a field for a Path that the user can drag and drop into the Path Follower’s Custom Inspector.

In this Custom Inspector I want to be able to access data on the referenced Path Behaviour.
Using serializedObject.FindProperty (), it successfully gets the reference to the path but when I try to then get the data from it, like the List of Way-Points, using say, Path.FindPropertyRelative (), everything returns null.

I am doing everything I should, to my knowledge, such as adding the SerializeFields, making sure everything is spelled correctly when finding the properties. Perhaps accessing a Monobehaviour from inside another is not possible?

Any help would be appreciated.
Here’s my simplified code:

Path:

using System.Collections.Generic;
using UnityEngine;

[System.Serializable]
public class Path : MonoBehaviour
{
    [SerializeField]
    public List<WayPoint> WayPoints = new List<WayPoint>();

    [System.Serializable]
    public class WayPoint
    {
        [SerializeField]
        public Vector2 Position = Vector2.zero;
    }
}

Path Follower:

using System.Collections.Generic;
using UnityEngine;

[System.Serializable]
public class PathFollower : MonoBehaviour
{
    [SerializeField]
    protected Path _path;
}

Path Follower Inspector

using System.Collections.Generic;
using UnityEditor;

[CustomEditor(typeof (PathFollower))]
public class PathFollowerEditor : Editor
{
    // Properties
    SerializedProperty pathProp;
    SerializedProperty wayPointsProp;

    void GetProperties()
    {
        pathProp = serializedObject.FindProperty("_path");
        wayPointsProp = pathProp.FindPropertyRelative("WayPoints");
    }

	void DrawInspector ()
	{
        EditorGUILayout.PropertyField(pathProp);

        // If there is a Path, utilize the Way Points' data...
    }
}

At this point, I don’t even need to change data from the Path, just that the Path Follower knows what the data is.

-Thanks in advance.

2

From all I could gather, checking out my own code using this and searching Answers finding this:

I came to the conclusion that FindPropertyRelative is only meant to be used on System.Serializable classes not deriving from either MonoBehaviour or ScriptableObject.
You’ll find the answer of how to work with your case in the other answer.