Refactor export button implementation to use gr.DownloadButton and update click handlers for file downloads

src/interface/file_upload_interface.py

@@ -779,9 +779,21 @@ def create_file_upload_interface() -> gr.Blocks:
                 # Export options
                 gr.Markdown("### 💾 Export Results")
                 with gr.Column():
-                    export_csv_btn = StandardizedComponents.create_export_button("csv")
-                    export_json_btn = StandardizedComponents.create_export_button("json")
-                    export_xlsx_btn = StandardizedComponents.create_export_button("xlsx")
+                    export_csv_btn = gr.DownloadButton(
+                        label="Download CSV",
+                        variant="secondary",
+                        visible=False,
+                    )
+                    export_json_btn = gr.DownloadButton(
+                        label="Download JSON",
+                        variant="secondary",
+                        visible=False,
+                    )
+                    export_xlsx_btn = gr.DownloadButton(
+                        label="Download XLSX",
+                        variant="secondary",
+                        visible=False,
+                    )
         
         # Status messages
         status_message = gr.Markdown("", visible=True)
@@ -826,6 +838,9 @@ def create_file_upload_interface() -> gr.Blocks:
                 "",                     # file_preview_display
                 None,                   # current_file_result_state
                 None,                   # current_session_state
+                gr.DownloadButton(visible=False),  # export_csv_btn
+                gr.DownloadButton(visible=False),  # export_json_btn
+                gr.DownloadButton(visible=False),  # export_xlsx_btn
                 "File cleared"          # status_message
             )
         
@@ -862,6 +877,9 @@ def create_file_upload_interface() -> gr.Blocks:
                         confidence_text,            # classifier_confidence_display
                         indicators_text,            # classifier_indicators_display
                         progress_text,              # batch_progress_display
+                        gr.DownloadButton(visible=False),  # export_csv_btn
+                        gr.DownloadButton(visible=False),  # export_json_btn
+                        gr.DownloadButton(visible=False),  # export_xlsx_btn
                         message                     # status_message
                     )
                 else:
@@ -874,6 +892,9 @@ def create_file_upload_interface() -> gr.Blocks:
                         "",                         # classifier_confidence_display
                         "",                         # classifier_indicators_display
                         "No messages to process",   # batch_progress_display
+                        gr.DownloadButton(visible=False),  # export_csv_btn
+                        gr.DownloadButton(visible=False),  # export_json_btn
+                        gr.DownloadButton(visible=False),  # export_xlsx_btn
                         "❌ No messages in file"    # status_message
                     )
             else:
@@ -886,6 +907,9 @@ def create_file_upload_interface() -> gr.Blocks:
                     "",                         # classifier_confidence_display
                     "",                         # classifier_indicators_display
                     "",                         # batch_progress_display
+                    gr.DownloadButton(visible=False),  # export_csv_btn
+                    gr.DownloadButton(visible=False),  # export_json_btn
+                    gr.DownloadButton(visible=False),  # export_xlsx_btn
                     message                     # status_message
                 )
         
@@ -922,6 +946,9 @@ def create_file_upload_interface() -> gr.Blocks:
                         progress_text,                  # batch_progress_display
                         stats_text,                     # batch_stats_display
                         gr.Row(visible=False),          # correction_section
+                        gr.DownloadButton(visible=True),  # export_csv_btn
+                        gr.DownloadButton(visible=True),  # export_json_btn
+                        gr.DownloadButton(visible=True),  # export_xlsx_btn
                         message                         # status_message
                     )
                 else:
@@ -942,6 +969,9 @@ def create_file_upload_interface() -> gr.Blocks:
                         "✅ Batch processing complete", # batch_progress_display
                         stats_text,                     # batch_stats_display
                         gr.Row(visible=False),          # correction_section
+                        gr.DownloadButton(visible=True),  # export_csv_btn
+                        gr.DownloadButton(visible=True),  # export_json_btn
+                        gr.DownloadButton(visible=True),  # export_xlsx_btn
                         message                         # status_message
                     )
             else:
@@ -954,6 +984,9 @@ def create_file_upload_interface() -> gr.Blocks:
                     gr.Markdown(value=""),      # batch_progress_display (no change)
                     gr.Markdown(value=""),      # batch_stats_display (no change)
                     gr.Row(visible=False),      # correction_section
+                    gr.DownloadButton(visible=False),  # export_csv_btn
+                    gr.DownloadButton(visible=False),  # export_json_btn
+                    gr.DownloadButton(visible=False),  # export_xlsx_btn
                     message                     # status_message
                 )
         
@@ -1000,6 +1033,9 @@ def create_file_upload_interface() -> gr.Blocks:
                         stats_text,                     # batch_stats_display
                         gr.Row(visible=False),          # correction_section
                         "",                             # correction_notes (clear)
+                        gr.DownloadButton(visible=True),  # export_csv_btn
+                        gr.DownloadButton(visible=True),  # export_json_btn
+                        gr.DownloadButton(visible=True),  # export_xlsx_btn
                         message                         # status_message
                     )
                 else:
@@ -1021,6 +1057,9 @@ def create_file_upload_interface() -> gr.Blocks:
                         stats_text,                     # batch_stats_display
                         gr.Row(visible=False),          # correction_section
                         "",                             # correction_notes (clear)
+                        gr.DownloadButton(visible=True),  # export_csv_btn
+                        gr.DownloadButton(visible=True),  # export_json_btn
+                        gr.DownloadButton(visible=True),  # export_xlsx_btn
                         message                         # status_message
                     )
             else:
@@ -1034,13 +1073,18 @@ def create_file_upload_interface() -> gr.Blocks:
                     gr.Markdown(value=""),      # batch_stats_display (no change)
                     gr.Row(visible=True),       # correction_section (keep visible)
                     notes,                      # correction_notes (keep)
+                    gr.DownloadButton(visible=False),  # export_csv_btn
+                    gr.DownloadButton(visible=False),  # export_json_btn
+                    gr.DownloadButton(visible=False),  # export_xlsx_btn
                     message                     # status_message
                 )
         
-        def on_export_results(format_type):
-            """Handle results export."""
+        def on_export_results_file(format_type):
+            """Handle results export and return the generated file for download."""
             success, message, file_path = controller.export_batch_results(format_type)
-            return message
+            if success and file_path:
+                return file_path
+            return None
         
         def on_download_csv_template():
             """Handle CSV template download."""
@@ -1086,6 +1130,9 @@ def create_file_upload_interface() -> gr.Blocks:
                 file_preview_display,
                 current_file_result_state,
                 current_session_state,
+                export_csv_btn,
+                export_json_btn,
+                export_xlsx_btn,
                 status_message
             ]
         )
@@ -1102,6 +1149,9 @@ def create_file_upload_interface() -> gr.Blocks:
                 classifier_confidence_display,
                 classifier_indicators_display,
                 batch_progress_display,
+                export_csv_btn,
+                export_json_btn,
+                export_xlsx_btn,
                 status_message
             ]
         )
@@ -1117,6 +1167,9 @@ def create_file_upload_interface() -> gr.Blocks:
                 batch_progress_display,
                 batch_stats_display,
                 correction_section,
+                export_csv_btn,
+                export_json_btn,
+                export_xlsx_btn,
                 status_message
             ]
         )
@@ -1139,24 +1192,16 @@ def create_file_upload_interface() -> gr.Blocks:
                 batch_stats_display,
                 correction_section,
                 correction_notes,
+                export_csv_btn,
+                export_json_btn,
+                export_xlsx_btn,
                 status_message
             ]
         )
         
-        export_csv_btn.click(
-            lambda: on_export_results("csv"),
-            outputs=[status_message]
-        )
-        
-        export_json_btn.click(
-            lambda: on_export_results("json"),
-            outputs=[status_message]
-        )
-        
-        export_xlsx_btn.click(
-            lambda: on_export_results("xlsx"),
-            outputs=[status_message]
-        )
+        export_csv_btn.click(lambda: on_export_results_file("csv"), outputs=[export_csv_btn])
+        export_json_btn.click(lambda: on_export_results_file("json"), outputs=[export_json_btn])
+        export_xlsx_btn.click(lambda: on_export_results_file("xlsx"), outputs=[export_xlsx_btn])
         
         download_csv_template_btn.click(
             on_download_csv_template,