Unity Inspector: require elements when boolean checked - unity3d

Question

How do I automatize the inspector such that if you don't click a serialized boolean, a component doesn't show up, when you click it, the corresponding component automatically shows up (as if it was required)?
Dropping journal not checked
You see I have not checked the boolean and the other component is not showing up indeed.
But when I click on the boolean I'd like that automatically this script shows up on the inspector.
Like this:
Dropping journal checked image
How can I do this?

Answer 1

You need to create custom editor.
Official documentation
using UnityEngine;
public class MyScript : MonoBehaviour
{
public bool Checked = false;
public GameObject SomeField;
}
Editor script.
using UnityEngine;
using UnityEditor;
[CustomEditor(typeof(MyScript))]
[CanEditMultipleObjects]
public class MyScriptEditor : Editor
{
SerializedProperty Checked;
SerializedProperty SomeField;
void OnEnable()
{
Checked = serializedObject.FindProperty("Checked");
SomeField = serializedObject.FindProperty("SomeField");
}
public override void OnInspectorGUI()
{
var myScript = (MyScript)target;
serializedObject.Update();
EditorGUILayout.PropertyField(Checked);
if(myScript.Checked)
EditorGUILayout.PropertyField(SomeField);
serializedObject.ApplyModifiedProperties();
}
}

Answer 2

You can use Attribute ExecuteInEditMode and then check in update function if boolean is true then just Add the second script to base component Here I attached simple script that give you idea
[ExecuteInEditMode]
public class TestScript : MonoBehaviour
{
public bool show = false;
void Update()
{
if (show)
{
base.gameObject.AddComponent<objectyouwanttoadd>();
}
}
}
Also you can implement logic that if other object is already attached or not also if you uncheck show bool then remove added object, also if current platform is unity Editor then only attach other component etc...