Refactor NO_RELOAD implementation (#10088)

* Refactor `NO_RELOAD` implementation

* add changeset

---------

Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>

.changeset/legal-geese-taste.md

@@ -0,0 +1,5 @@
+---
+"gradio": minor
+---
+
+feat:Refactor `NO_RELOAD` implementation

gradio/utils.py

@@ -172,10 +172,21 @@ def swap_blocks(self, demo: Blocks):
         self.alert_change("reload")
 
 
-NO_RELOAD = True
+class DynamicBoolean(int):
+    def __init__(self, value: int):
+        self.value = bool(value)
 
+    def __bool__(self):
+        return self.value
 
-def _remove_no_reload_codeblocks(file_path: str):
+    def set(self, value: int):
+        self.value = bool(value)
+
+
+NO_RELOAD = DynamicBoolean(True)
+
+
+def _remove_if_name_main_codeblock(file_path: str):
     """Parse the file, remove the gr.no_reload code blocks, and write the file back to disk.
 
     Parameters:
@@ -187,16 +198,6 @@ def _remove_no_reload_codeblocks(file_path: str):
 
     tree = ast.parse(code)
 
-    def _is_gr_no_reload(expr: ast.AST) -> bool:
-        """Find with gr.no_reload context managers."""
-        return (
-            isinstance(expr, ast.If)
-            and isinstance(expr.test, ast.Attribute)
-            and isinstance(expr.test.value, ast.Name)
-            and expr.test.value.id == "gr"
-            and expr.test.attr == "NO_RELOAD"
-        )
-
     def _is_if_name_main(expr: ast.AST) -> bool:
         """Find the if __name__ == '__main__': block."""
         return (
@@ -212,7 +213,7 @@ def _is_if_name_main(expr: ast.AST) -> bool:
 
     # Find the positions of the code blocks to load
     for node in ast.walk(tree):
-        if _is_gr_no_reload(node) or _is_if_name_main(node):
+        if _is_if_name_main(node):
             assert isinstance(node, ast.If)  # noqa: S101
             node.body = [ast.Pass(lineno=node.lineno, col_offset=node.col_offset)]
 
@@ -236,6 +237,8 @@ def watchfn(reloader: SourceFileReloader):
     get_changes is taken from uvicorn's default file watcher.
     """
 
+    NO_RELOAD.set(False)
+
     # The thread running watchfn will be the thread reloading
     # the app. So we need to modify this thread_data attr here
     # so that subsequent calls to reload don't launch the app
@@ -275,7 +278,7 @@ def iter_py_files() -> Iterator[Path]:
     # Need to import the module in this thread so that the
     # module is available in the namespace of this thread
     module = reloader.watch_module
-    no_reload_source_code = _remove_no_reload_codeblocks(str(reloader.demo_file))
+    no_reload_source_code = _remove_if_name_main_codeblock(str(reloader.demo_file))
     exec(no_reload_source_code, module.__dict__)
     sys.modules[reloader.watch_module_name] = module
 
@@ -294,7 +297,7 @@ def iter_py_files() -> Iterator[Path]:
                 # changes to be reflected in the main demo file.
 
                 if changed.suffix == ".py":
-                    changed_in_copy = _remove_no_reload_codeblocks(str(changed))
+                    changed_in_copy = _remove_if_name_main_codeblock(str(changed))
                     if changed != reloader.demo_file:
                         changed_module = _find_module(changed)
                         if changed_module:
@@ -305,7 +308,7 @@ def iter_py_files() -> Iterator[Path]:
                             if top_level_parent != changed_module:
                                 importlib.reload(top_level_parent)
 
-                changed_demo_file = _remove_no_reload_codeblocks(
+                changed_demo_file = _remove_if_name_main_codeblock(
                     str(reloader.demo_file)
                 )
                 exec(changed_demo_file, module.__dict__)