expose NoUpdate

dash/__init__.py

@@ -19,7 +19,7 @@
 from . import dash_table # noqa: F401,E402
 from .version import __version__ # noqa: F401,E402
 from ._callback_context import callback_context # noqa: F401,E402
-from ._callback import callback, clientside_callback # noqa: F401,E402
+from ._callback import callback, clientside_callback, NoUpdateType # noqa: F401,E402
 from ._get_app import get_app # noqa: F401,E402
 from ._get_paths import ( # noqa: F401,E402
  get_asset_url,

dash/_callback.py

@@ -39,13 +39,13 @@ def _invoke_callback(func, *args, **kwargs): # used to mark the frame for the d
  return func(*args, **kwargs) # %% callback invoked %%
 
 
-class NoUpdate:
+class NoUpdateType:
  def to_plotly_json(self): # pylint: disable=no-self-use
  return {"_dash_no_update": "_dash_no_update"}
 
  @staticmethod
  def is_no_update(obj):
- return isinstance(obj, NoUpdate) or (
+ return isinstance(obj, NoUpdateType) or (
  isinstance(obj, dict) and obj == {"_dash_no_update": "_dash_no_update"}
  )
 
@@ -423,7 +423,7 @@ def add_context(*args, **kwargs):
  job_running = callback_manager.job_running(job_id)
  if not job_running and output_value is callback_manager.UNDEFINED:
  # Job canceled -> no output to close the loop.
- output_value = NoUpdate()
+ output_value = NoUpdateType()
 
  elif (
  isinstance(output_value, dict)
@@ -440,7 +440,7 @@ def add_context(*args, **kwargs):
 
  if multi and isinstance(output_value, (list, tuple)):
  output_value = [
- NoUpdate() if NoUpdate.is_no_update(r) else r
+ NoUpdateType() if NoUpdateType.is_no_update(r) else r
  for r in output_value
  ]
 
@@ -449,7 +449,7 @@ def add_context(*args, **kwargs):
  else:
  output_value = _invoke_callback(func, *func_args, **func_kwargs)
 
- if NoUpdate.is_no_update(output_value):
+ if NoUpdateType.is_no_update(output_value):
  raise PreventUpdate
 
  if not multi:
@@ -471,12 +471,12 @@ def add_context(*args, **kwargs):
  component_ids = collections.defaultdict(dict)
  has_update = False
  for val, spec in zip(flat_output_values, output_spec):
- if isinstance(val, NoUpdate):
+ if isinstance(val, NoUpdateType):
  continue
  for vali, speci in (
  zip(val, spec) if isinstance(spec, list) else [[val, spec]]
  ):
- if not isinstance(vali, NoUpdate):
+ if not isinstance(vali, NoUpdateType):
  has_update = True
  id_str = stringify_id(speci["id"])
  prop = clean_property_name(speci["property"])

dash/dash.py

@@ -187,7 +187,7 @@ def _do_skip(error):
 
 
 # Singleton signal to not update an output, alternative to PreventUpdate
-no_update = _callback.NoUpdate() # pylint: disable=protected-access
+no_update = _callback.NoUpdateType() # pylint: disable=protected-access
 
 
 # pylint: disable=too-many-instance-attributes

dash/long_callback/managers/celery_manager.py

@@ -152,7 +152,7 @@ def run():
  else:
  user_callback_output = fn(*maybe_progress, user_callback_args)
  except PreventUpdate:
- # Put NoUpdate dict directly to avoid circular imports.
+ # Put NoUpdateType dict directly to avoid circular imports.
  cache.set(
  result_key,
  json.dumps(