Update app.py

app.py

@@ -51,20 +51,23 @@ def plot_dot(file, x_param, y_param):
 # Function to dynamically update parameter options after file upload
 def get_parameters(file):
     if not file:
-        return [], []
+        # Return empty dropdown updates if no file is uploaded
+        return gr.Dropdown.update(choices=[]), gr.Dropdown.update(choices=[])
 
     try:
         _, columns = parse_fcs(file)
         return gr.Dropdown.update(choices=columns), gr.Dropdown.update(choices=columns)
     except Exception as e:
-        return [f"Error: {e}"], [f"Error: {e}"]
+        # Log the error and return empty dropdowns
+        print(f"Error parsing FCS file: {e}")
+        return gr.Dropdown.update(choices=[], value=None), gr.Dropdown.update(choices=[], value=None)
 
 # Create Gradio interface
 with gr.Blocks() as app:
     gr.Markdown("# Flow Cytometry Dot Plot Viewer")
 
     with gr.Row():
-        fcs_file = gr.File(label="Upload FCS File")
+        fcs_file = gr.File(label="Upload FCS File", file_types=[".fcs"])
 
     with gr.Row():
         x_param = gr.Dropdown(label="X Parameter", choices=[], interactive=True)