Automate mutable values (#12)

* Enable persisting of mutable objects throughout scenes, replace extensions with Unity hooks

* Update changelog and docs

Author: Edvinas01

CHANGELOG.md

@@ -4,6 +4,19 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.4.0] - 2020-10-07
+
+### Added
+- `MutableObjectHandler` which would automate the process of resetting `MutableObjects`.
+- `Persisting` property on `IMutableObject` which determines how resetting should be handled.
+
+### Changed
+- Cleaned up `MutableObject` sample.
+- Updated documentation.
+
+### Removed
+- `MutableObjectExtensions` as its purpose is now automated.
+
 ## [0.3.0] - 2020-10-05
 
 ### Added

Documentation~/README.md

@@ -31,7 +31,7 @@ Available game events:
   width="100%" alt="Example usage of Mutable Objects"
 />
 
-Mutable objects are used for storing and editing data on `ScriptableObject` assets at runtime. This data can be referenced, observed and used as a bridge by various scripts. Mutable objects are useful in situations where `ScriptableObject` data needs to be reset when a new level loads (e.g. in `Awake` on a `GameManager` script with a properly setup [Script Execution Order](https://docs.unity3d.com/Manual/class-MonoManager.html)). Mutable objects can be reset using `MutableObjectExtensions.ResetMutatedObjects()` method.
+Mutable objects are used for storing and editing data on `ScriptableObject` assets at runtime. This data can be referenced, observed and used as a bridge by various scripts. Mutable objects are useful in situations where `ScriptableObject` data needs to be reset when a new level loads.
 
 Available mutable objects:
 - `MutableBool` - encapsulates a `bool` value.
@@ -41,6 +41,8 @@ Available mutable objects:
 - `MutableVector2` - encapsulates a `Vector2` value.
 - `MutableVector3` - encapsulates a `Vector3` value.
 
+If a mutable object value should be saved between scene loads, check the `Persisting` flag on the `MutableObject` asset.
+
 ### Custom game events
 In some situations, built-in game events might not suffice. For example if a custom type needs to be passed as an argument to the event. In this case, custom game event can be created which would carry all the necessary data.
 
@@ -102,5 +104,3 @@ public class MutableCustom : MutableObject
     }
 }
 ```
-
-[Unity Package Manager]: https://docs.unity3d.com/Packages/com.unity.package-manager-ui@2.0/manual/index.html

Runtime/MutableObjects/Extensions.meta

@@ -2,6 +2,11 @@
 {
     public interface IMutableObject
     {
+        /// <summary>
+        ///     Is this mutable object persisting throughout the scenes and should not be reset.
+        /// </summary>
+        bool Persisting { get; }
+
         /// <summary>
         ///     Reset values on this mutable object to their original ones.
         /// </summary>

Runtime/MutableObjects/Extensions/MutableObjectExtensions.cs

@@ -4,6 +4,12 @@ namespace MutableObjects.Generic
 {
     public abstract class MutableObject : ScriptableObject, IMutableObject
     {
+        [SerializeField]
+        [Tooltip("Should this mutable object be persisted throughout scene loads")]
+        private bool persisting = false;
+
+        public bool Persisting => persisting;
+
         public abstract void ResetValues();
 
         private void OnValidate()

Runtime/MutableObjects/Extensions/MutableObjectExtensions.cs.meta

@@ -0,0 +1,43 @@
+using System.Collections.Generic;
+using System.Linq;
+using MutableObjects.Generic;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+
+namespace MutableObjects
+{
+    public static class MutableObjectHandler
+    {
+        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
+        private static void RuntimeInit()
+        {
+            SetInitialMutableObjectValues();
+            SceneManager.sceneUnloaded += scene => ResetMutableObjectValues();
+        }
+
+        private static void SetInitialMutableObjectValues()
+        {
+            var mutableObjects = FindMutableObjects();
+            foreach (var mutableObject in mutableObjects)
+            {
+                mutableObject.ResetValues();
+            }
+        }
+
+        private static void ResetMutableObjectValues()
+        {
+            var mutableObjects = FindMutableObjects()
+                .Where(mutableObject => !mutableObject.Persisting);
+
+            foreach (var mutableObject in mutableObjects)
+            {
+                mutableObject.ResetValues();
+            }
+        }
+
+        private static IEnumerable<IMutableObject> FindMutableObjects()
+        {
+            return Resources.FindObjectsOfTypeAll<MutableObject>();
+        }
+    }
+}