add app

app.py

@@ -103,15 +103,17 @@ def main():
 
         # Update previews when files are uploaded
         def update_previews(ref_file, hyp_file):
+            ref_text = ""
+            hyp_text = ""
+
             if ref_file:
                 with open(ref_file.name, 'r') as f:
-                    ref_text = f.read()
-                    return ref_text[:200]  # Show first 200 characters
+                    ref_text = f.read()[:200]  # Show first 200 characters
             if hyp_file:
                 with open(hyp_file.name, 'r') as f:
-                    hyp_text = f.read()
-                    return hyp_text[:200]  # Show first 200 characters
-            return "", ""
+                    hyp_text = f.read()[:200]  # Show first 200 characters
+
+            return ref_text, hyp_text
 
         reference_file.change(
             fn=update_previews,