Build Resources.FindObjectsOfTypeAll bugfix

Editor/Build/MetadataLookupBuild.cs

@@ -1,18 +1,28 @@
-using UnityEditor;
+using System;
+using System.Collections.Generic;
+using UnityEditor;
 using UnityEditor.Build;
 using UnityEditor.Build.Reporting;
 using UnityEngine;
 
 // This is a bit of a hack, but we need to ensure that our metadata is not stripped on build,
-// so at build time we clone them into a temporary resources directory. Afterwards we delete the directory.
-// Cloning works since each metadata object holds a reference to the thing it belongs to and we can
-// just use the clone at runtime instead.
+// so at build time we clone them into a temporary resources directory. Cloning works since 
+// each metadata object holds a reference to the thing it belongs to and we can just use the 
+// clone at runtime instead. After we've created the build we delete the directory.
 public class MetadataLookupPreprocessBuild : IPreprocessBuildWithReport
 {
     public int callbackOrder { get { return 0; } }
 
     public static bool HadResourcesDirectory = false;
 
+    CustomAssetMetadata CloneCustomAssetMetadata(CustomAssetMetadata assetMetadata, string basePath, ref int index)
+    {
+        var clone = UnityEngine.Object.Instantiate(assetMetadata);
+        var name = $"{assetMetadata.GetInstanceID()}-{index}"; index++;
+        AssetDatabase.CreateAsset(clone, $"{basePath}/{name}.asset");
+        return clone;
+    }
+
     public void OnPreprocessBuild(BuildReport report)
     {
         const string basePath = "Assets/Resources/" + MetadataLookup.kResourcePath;
@@ -22,17 +32,34 @@ public void OnPreprocessBuild(BuildReport report)
             System.IO.Directory.Delete(basePath, true);
         System.IO.Directory.CreateDirectory(basePath);
         var list = ScriptableObject.CreateInstance<MetadataLookupAsset>();
-		var allMetadata = Resources.FindObjectsOfTypeAll<CustomAssetMetadata>();
+
+        var allMetadata = new List<CustomAssetMetadata>();
+
+        var allPaths = UnityEditor.AssetDatabase.FindAssets($"t:Material"); // TODO: support more than just materials
+        foreach(var assetPath in allPaths)
+        {         
+            foreach (var item in UnityEditor.AssetDatabase.LoadAllAssetRepresentationsAtPath(assetPath))
+            {
+                if (item is not CustomAssetMetadata metadata)
+                    continue;
+                allMetadata.Add(metadata);
+            }
+            UnityEditor.EditorUtility.UnloadUnusedAssetsImmediate();
+        }
+
+        // This doesn't work since Resources.FindObjectsOfTypeAll only works on 
+        // assets currently loaded into memory.		
+        //allMetadata.AddRange(Resources.FindObjectsOfTypeAll<CustomAssetMetadata>());
+
         int index = 0;
-        for (int i = 0; i < allMetadata.Length; i++)
-		{
-			var clone = UnityEngine.Object.Instantiate(allMetadata[i]);
-			var name = $"{allMetadata[i].GetInstanceID()}-{index}"; index++;
-			AssetDatabase.CreateAsset(clone, $"{basePath}/{name}.asset");
-            allMetadata[i] = clone;
+        for (int i = 0; i < allMetadata.Count; i++)
+        {
+            allMetadata[i] = CloneCustomAssetMetadata(allMetadata[i], basePath, ref index);
         }
-        list.allMetadata = allMetadata;
-		AssetDatabase.CreateAsset(list, $"{basePath}/{MetadataLookup.kAssetName}.asset");
+        UnityEditor.EditorUtility.UnloadUnusedAssetsImmediate();
+
+        list.allMetadata = allMetadata.ToArray();
+        AssetDatabase.CreateAsset(list, $"{basePath}/{MetadataLookup.kAssetName}.asset");
         AssetDatabase.StopAssetEditing();
     }
 

Runtime/Common/MetadataLookup.cs

@@ -1,14 +1,15 @@
-
+
 #if !UNITY_EDITOR
 #define UNITY_RUNTIME
 #endif
+using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using UnityEngine;
 
 internal static class MetadataLookup
 {
-    public const string kResourcePath = "AssetMetadata";
+    public const string kResourcePath = "__AssetMetadata";
     public const string kAssetName = "list.asset";
 
     readonly static Dictionary<int, List<CustomAssetMetadata>> table = new();
@@ -110,7 +111,7 @@ internal static bool Register(UnityEngine.LazyLoadReference<UnityEngine.Object>
 	internal static void Unregister(UnityEngine.LazyLoadReference<UnityEngine.Object> reference, CustomAssetMetadata metadata)
 	{
 		if (reference.isBroken || !reference.isSet ||
-			object.ReferenceEquals(metadata, null))
+			object.ReferenceEquals(metadata, null)) 
 			return;
 
 		if (!table.TryGetValue(reference.instanceID, out var metadataList))
@@ -119,7 +120,7 @@ internal static void Unregister(UnityEngine.LazyLoadReference<UnityEngine.Object
 		metadataList.Remove(metadata);
         if (metadataList.Count == 0)
         {
-            table.Remove(reference.instanceID);
+			table.Remove(reference.instanceID);
         }
 	}
 
@@ -130,32 +131,41 @@ static bool RegisterMetadataForAsset(string assetPath)
 			return false;
 
 		bool foundAny = false;
-		foreach (var item in UnityEditor.AssetDatabase.LoadAllAssetsAtPath(assetPath))
+		var subAssets = UnityEditor.AssetDatabase.LoadAllAssetRepresentationsAtPath(assetPath);		
+		foreach (var item in subAssets)
 		{
 			if (item is not CustomAssetMetadata metadata)
 				continue;
 
 			foundAny = MetadataLookup.Register(metadata.reference.asset, metadata) || foundAny;
 		}
+		UnityEditor.EditorUtility.UnloadUnusedAssetsImmediate();
 		return foundAny;
 	}
 #endif
 
 	static bool GetAllMetadataForAsset(UnityEngine.Object asset, out List<CustomAssetMetadata> result)
     {
-        EnsureInitialized();
-        if (table.TryGetValue(asset.GetInstanceID(), out result))
-            return true;
+		if (asset)
+		{
+			EnsureInitialized();
+			if (table.TryGetValue(asset.GetInstanceID(), out result))
+				return true;
 #if UNITY_EDITOR
-        if (Application.isEditor)
-        {
-            var assetPath = UnityEditor.AssetDatabase.GetAssetPath(asset);
-            RegisterMetadataForAsset(assetPath);
-            if (table.TryGetValue(asset.GetInstanceID(), out result))
-                return true;
-        }
+			if (Application.isEditor)
+			{
+				var assetPath = UnityEditor.AssetDatabase.GetAssetPath(asset);
+				if (!RegisterMetadataForAsset(assetPath))
+				{
+					result = null;
+					return false;
+				}
+				if (table.TryGetValue(asset.GetInstanceID(), out result))
+					return true;
+			}
 #endif
-        result = null;
+		}
+		result = null;
         return false;
     }
 
@@ -192,7 +202,7 @@ static void InitializeEditor()
 			var allMetadata = Resources.FindObjectsOfTypeAll<CustomAssetMetadata>();
 			foreach (var metadata in allMetadata)
 			{
-				if (metadata != null)
+				if (!metadata)
 					continue;
 				var assetPath = UnityEditor.AssetDatabase.GetAssetPath(metadata);
 				RegisterMetadataForAsset(assetPath);

package.json

@@ -1,7 +1,7 @@
 {
     "name": "com.custom_asset_metadata",
     "displayName": "Custom Asset Metadata",
-    "version": "1.2.1",
+    "version": "1.2.2",
     "unity": "2020.3",
     "description": "Adds the ability to store meta data on Assets",
     "license": "MIT",