add demo mode for web UI

src/llmtuner/webui/interface.py

@@ -1,4 +1,5 @@
 import gradio as gr
+from typing import Optional
 from transformers.utils.versions import require_version
 
 from llmtuner.webui.components import (
@@ -17,10 +18,20 @@ from llmtuner.webui.engine import Engine
 require_version("gradio>=3.38.0,<4.0.0", "To fix: pip install \"gradio>=3.38.0,<4.0.0\"")
 
 
-def create_ui() -> gr.Blocks:
-    engine = Engine(pure_chat=False)
+def create_ui(demo_mode: Optional[bool] = False) -> gr.Blocks:
+    engine = Engine(demo_mode=demo_mode, pure_chat=False)
 
     with gr.Blocks(title="LLaMA Board", css=CSS) as demo:
+        if demo_mode:
+            gr.HTML(
+                "<h1><center>LLaMA Board: A One-stop Web UI for Getting Started with LLaMA Factory</center></h1>"
+            )
+            gr.HTML(
+                "<h3><center>Visit <a href=\"https://github.com/hiyouga/LLaMA-Factory\" target=\"_blank\">"
+                "LLaMA Factory</a> for details.</center></h3>"
+            )
+            gr.DuplicateButton(value="Duplicate Space for private use", elem_classes="duplicate-button")
+
         engine.manager.all_elems["top"] = create_top()
         lang: "gr.Dropdown" = engine.manager.get_elem_by_name("top.lang")
 
@@ -33,8 +44,9 @@ def create_ui() -> gr.Blocks:
         with gr.Tab("Chat"):
             engine.manager.all_elems["infer"] = create_infer_tab(engine)
 
-        with gr.Tab("Export"):
-            engine.manager.all_elems["export"] = create_export_tab(engine)
+        if not demo_mode:
+            with gr.Tab("Export"):
+                engine.manager.all_elems["export"] = create_export_tab(engine)
 
         demo.load(engine.resume, outputs=engine.manager.list_elems())
         lang.change(engine.change_lang, [lang], engine.manager.list_elems(), queue=False)