feat: Prefab Template Processors (#453)

* Added OnPrefabProcessor method to PrefabTemplates

* Singular prefab processor bug

Fixed a bug where you could only register one prefab processor

Nautilus/Assets/CustomPrefab.cs

@@ -259,7 +259,11 @@ public void AddOnUnregister(Action onUnregisterCallback)
     /// Sets a prefab template as the game object constructor of this custom prefab.
     /// </summary>
     /// <param name="prefabTemplate">The prefab template object to set.</param>
-    public void SetGameObject(PrefabTemplate prefabTemplate) => Prefab = prefabTemplate.GetPrefabAsync;
+    public void SetGameObject(PrefabTemplate prefabTemplate)
+    {
+        Prefab = prefabTemplate.GetPrefabAsync;
+        SetPrefabPostProcessor(prefabTemplate.OnPrefabPostProcessor);
+    }
 
     /// <summary>
     /// Sets a game object as the prefab of this custom prefab.
@@ -282,13 +286,13 @@ public void SetGameObject(GameObject prefab)
     /// Sets a post processor for the <see cref="Prefab"/>. This is an asynchronous version.
     /// </summary>
     /// <param name="postProcessorAsync">The post processor to set.</param>
-    public void SetPrefabPostProcessor(Func<GameObject, IEnumerator> postProcessorAsync) => OnPrefabPostProcess = obj => postProcessorAsync(obj);
+    public void SetPrefabPostProcessor(Func<GameObject, IEnumerator> postProcessorAsync) => OnPrefabPostProcess += obj => postProcessorAsync(obj);
 
     /// <summary>
     /// Sets a post processor for the <see cref="Prefab"/>. This is a synchronous version.
     /// </summary>
     /// <param name="postProcessor">The post processor to set.</param>
-    public void SetPrefabPostProcessor(Action<GameObject> postProcessor) => OnPrefabPostProcess = obj => SyncPostProcessor(obj, postProcessor);
+    public void SetPrefabPostProcessor(Action<GameObject> postProcessor) => OnPrefabPostProcess += obj => SyncPostProcessor(obj, postProcessor);
 
     /// <summary>
     /// Registers this custom prefab into the game.

Nautilus/Assets/PrefabTemplates/PrefabTemplate.cs

@@ -29,4 +29,14 @@ public PrefabTemplate(PrefabInfo info)
     /// If the provided task result already has a game object set to it, it will try to set the necessary components first. Otherwise; sets a default implementation of this entity type.</param>
     /// <returns>A coroutine operation. Must be used with either <c>yield return</c>, or <see cref="MonoBehaviour.StartCoroutine(IEnumerator)"/>.</returns>
     public abstract IEnumerator GetPrefabAsync(TaskResult<GameObject> gameObject);
+
+    /// <summary>
+    /// Use this method to make changes to the prefab after the Nautilus' prefab processing is completed. Can be used to override or add more features to a prefab once it's settled. 
+    /// </summary>
+    /// <param name="prefab">The prefab to process.</param>
+    /// <returns>A coroutine operation.</returns>
+    public virtual IEnumerator OnPrefabPostProcessor(GameObject prefab)
+    {
+        yield break;
+    }
 }