fix for app getting dsetroyed, which removes handlers before internal usage is stopped

Author: Martin Valigursky

src/framework/asset/asset-registry.js

@@ -222,6 +222,16 @@ class AssetRegistry extends EventHandler {
         this._loader = loader;
     }
 
+    /**
+     * The ResourceLoader used to load asset files.
+     *
+     * @type {ResourceLoader}
+     * @ignore
+     */
+    get loader() {
+        return this._loader;
+    }
+
     /**
      * Create a filtered list of assets from the registry.
      *

src/framework/components/gsplat/gsplat-asset-loader.js

@@ -116,6 +116,17 @@ class GSplatAssetLoader extends GSplatAssetLoaderBase {
         this._retryCount.clear();
     }
 
+    /**
+     * Checks if the loader can start new loads. Returns false if the 'gsplat' handler
+     * has been removed from the registry (e.g., during app destruction).
+     *
+     * @returns {boolean} True if loading is possible, false otherwise.
+     * @private
+     */
+    _canLoad() {
+        return !!this._registry.loader?.getHandler('gsplat');
+    }
+
     /**
      * Initiates loading of a gsplat asset. This is a fire-and-forget operation that starts
      * the loading process. Use getResource() later to check if the asset has finished loading.
@@ -217,8 +228,8 @@ class GSplatAssetLoader extends GSplatAssetLoaderBase {
      * @private
      */
     _onAssetLoadError(url, asset, err) {
-        // Don't process if destroyed or already unloaded
-        if (this._destroyed || !this._urlToAsset.has(url)) {
+        // Don't process if destroyed, handler removed, or already unloaded
+        if (this._destroyed || !this._canLoad() || !this._urlToAsset.has(url)) {
             return;
         }
 
@@ -256,8 +267,8 @@ class GSplatAssetLoader extends GSplatAssetLoaderBase {
      * @private
      */
     _processQueue() {
-        // Don't process queue if destroyed
-        if (this._destroyed) {
+        // Don't process queue if destroyed or handler removed
+        if (this._destroyed || !this._canLoad()) {
             return;
         }
 

src/scene/gsplat-unified/gsplat-asset-loader-base.js

@@ -5,6 +5,7 @@ import { Debug } from '../../core/debug.js';
  * GSplat asset loaders must implement.
  *
  * @category Asset
+ * @ignore
  */
 class GSplatAssetLoaderBase {
     /**