Merge pull request #214 from ManageXR/feature/eng-584-fix-nullreferenceexception-in-mxrstoragegetfullpath

ENG-584: Fix NullReferenceException in MXRStorage.GetFullPath

Author: adrenak

Assets/MXR.SDK/Runtime/Utils/MXRStorage.cs

@@ -43,9 +43,15 @@ public static string ExternalStorageDirectory {
         public static string MXRRootDirectory => Path.Combine(ExternalStorageDirectory, "MightyImmersion");
 
         /// <summary>
-        /// Returns the full path to a sub path inside <see cref="ExternalStorageDirectory"/>
+        /// Returns the full path to a sub path inside <see cref="ExternalStorageDirectory"/>.
+        /// Returns null if the provided path is null or empty.
         /// </summary>
+        /// <param name="path">The relative path to convert to a full path. May be null or empty.</param>
+        /// <returns>The full path, or null if the input path is null or empty.</returns>
         public static string GetFullPath(string path) {
+            if (string.IsNullOrEmpty(path))
+                return null;
+
             path = TryRemoveLeadingSpash(path);
             return Path.Combine(ExternalStorageDirectory, path);
         }

Assets/MXR.SDK/Samples/Scripts/ImageDownloader.cs

@@ -31,6 +31,11 @@ public void Download(string url, Action<Texture2D> callback) {
         /// <param name="onSuccess">Callback invoked when the load is successful.</param>
         /// <param name="onError">Callback invoked when the load fails.</param>
         public void Load(string location, TextureFormat format, bool mipMap, Action<Texture2D> onSuccess, Action<Exception> onError) {
+            if (string.IsNullOrEmpty(location)) {
+                onError?.Invoke(new Exception("Cannot load image from null or empty location"));
+                return;
+            }
+
             // If the location is a URL, we use the remote download method
             if (location.Contains("http://") || location.Contains("https://"))
                 LoadFromURL(location, format, mipMap, onSuccess, onError);

Assets/MXR.SDK/Samples/Scripts/RuntimeAppCell.cs

@@ -20,10 +20,12 @@ public class RuntimeAppCell : MonoBehaviour {
         public void Refresh() {
             title.text = runtimeApp.title;
 
-            // Instead of MXRStorage.GetFullPath(runtimeApp.iconPath) you can also use
-            // runtimeApp.iconUrl to download the icon from a URL, like this:
-            //new ImageDownloader().Load(runtimeApp.iconUrl, TextureFormat.ARGB32, true, result =>{}, error =>{});
-            new ImageDownloader().Load(MXRStorage.GetFullPath(runtimeApp.iconPath), TextureFormat.ARGB32, true,
+            // Try local path first, fall back to remote URL if not available
+            string iconLocation = string.IsNullOrEmpty(runtimeApp.iconPath)
+                ? runtimeApp.iconUrl
+                : MXRStorage.GetFullPath(runtimeApp.iconPath);
+
+            new ImageDownloader().Load(iconLocation, TextureFormat.ARGB32, true,
                 result => {
                     if (isBeingDestroyed) return;
 

Assets/MXR.SDK/Samples/Scripts/VideoCell.cs

@@ -18,10 +18,12 @@ public class VideoCell : MonoBehaviour {
         public void Refresh() {
             title.text = video.title;
 
-            // Instead of MXRStorage.GetFullPath(video.iconPath) you can also use
-            // video.iconUrl to download the icon from a URL, like this:
-            //new ImageDownloader().Load(video.iconUrl, TextureFormat.ARGB32, true, result =>{}, error =>{});
-            new ImageDownloader().Load(MXRStorage.GetFullPath(video.iconPath), TextureFormat.ARGB32, true,
+            // Try local path first, fall back to remote URL if not available
+            string iconLocation = string.IsNullOrEmpty(video.iconPath)
+                ? video.iconUrl
+                : MXRStorage.GetFullPath(video.iconPath);
+
+            new ImageDownloader().Load(iconLocation, TextureFormat.ARGB32, true,
                 result => {
                     if (isBeingDestroyed) return;
 

Assets/MXR.SDK/Samples/Scripts/WebXRAppCell.cs

@@ -14,11 +14,12 @@ public class WebXRAppCell : MonoBehaviour {
         public void Refresh() {
             title.text = webXRApp.title;
 
-            // Instead of MXRStorage.GetFullPath(webXRApp.iconPath) you can also use
-            // webXRApp.iconUrl to download the icon from a URL, like this:
-            //new ImageDownloader().Load(webXRApp.iconUrl, TextureFormat.ARGB32, true, result =>{}, error =>{});
+            // Try local path first, fall back to remote URL if not available
+            string iconLocation = string.IsNullOrEmpty(webXRApp.iconPath)
+                ? webXRApp.iconUrl
+                : MXRStorage.GetFullPath(webXRApp.iconPath);
 
-            new ImageDownloader().Load(MXRStorage.GetFullPath(webXRApp.iconPath), TextureFormat.ARGB32, true,
+            new ImageDownloader().Load(iconLocation, TextureFormat.ARGB32, true,
                 result => {
                     if (isBeingDestroyed) return;