add error

app.py

@@ -6,6 +6,19 @@ import os
 # Create your own Gradio interface instead of using the built-in widget
 def create_interface(module):
     def evaluate_fn(prediction, references, pos_pred, neg_pred):
+        # Check if all required fields are filled
+        if not prediction or prediction.strip() == "":
+            return "", "", "", "Please provide a candidate hypothesis to evaluate."
+
+        if not references or references.strip() == "":
+            return "", "", "", "Please provide a validation program."
+
+        if not pos_pred or pos_pred.strip() == "":
+            return "", "", "", "Please specify the positive predicate name."
+
+        if not neg_pred or neg_pred.strip() == "":
+            return "", "", "", "Please specify the negative predicate name."
+
         # Process a single prediction instead of multiple
         pred = prediction.strip()