Initial release of ComfyUI Subfolder Image Loader

Features:
  - Subfolder navigation and dynamic image filtering
  - Support for all common image formats
  - Transparency mask extraction
  - Security validation and error handling
  - JavaScript frontend for real-time UI updates

utils/file_helpers.py

@@ -0,0 +1,49 @@
+# utils/file_helpers.py
+import os
+import time
+from typing import List, Dict, Optional
+import logging
+
+class FileCache:
+    """Simple file listing cache to improve performance."""
+    
+    def __init__(self, cache_timeout: int = 5):
+        self.cache_timeout = cache_timeout
+        self._cache: Dict[str, List[str]] = {}
+        self._timestamps: Dict[str, float] = {}
+    
+    def get_files(self, directory: str, force_refresh: bool = False) -> List[str]:
+        """Get cached file listing or refresh if needed."""
+        current_time = time.time()
+        
+        if (not force_refresh and 
+            directory in self._timestamps and 
+            current_time - self._timestamps[directory] < self.cache_timeout):
+            return self._cache.get(directory, [])
+        
+        # Refresh cache
+        files = self._scan_directory(directory)
+        self._cache[directory] = files
+        self._timestamps[directory] = current_time
+        
+        return files
+    
+    def _scan_directory(self, directory: str) -> List[str]:
+        """Scan directory for image files."""
+        if not os.path.exists(directory):
+            return []
+        
+        valid_extensions = {'.png', '.jpg', '.jpeg', '.webp', '.bmp', '.tiff', '.tif'}
+        files = []
+        
+        try:
+            for file in os.listdir(directory):
+                if os.path.splitext(file.lower())[1] in valid_extensions:
+                    files.append(file)
+        except PermissionError:
+            logging.warning(f"Permission denied accessing {directory}")
+        
+        return sorted(files)
+
+# Global cache instance
+file_cache = FileCache()