support named callback args not wrapped in a list

CHANGELOG.md

@@ -3,14 +3,13 @@ All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
-### Changed
-- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
-
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
 
 ### Changed
-- [#1180](https://github.com/plotly/dash/pull/1180) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1180](https://github.com/plotly/dash/pull/1180) and [#1375](https://github.com/plotly/dash/pull/1375) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
+
 
 ## [1.14.0] - 2020-07-27
 ### Added

dash/dependencies.py

@@ -140,7 +140,13 @@ def __repr__(self):
 def extract_callback_args(args, kwargs, name, type_):
  """Extract arguments for callback from a name and type"""
  parameters = kwargs.get(name, [])
- if not parameters:
+ if parameters:
+ if not isinstance(parameters, (list, tuple)):
+ # accept a single item, not wrapped in a list, for any of the
+ # categories as a named arg (even though previously only output
+ # could be given unwrapped)
+ return [parameters]
+ else:
  while args and isinstance(args[0], type_):
  parameters.append(args.pop(0))
  return parameters
@@ -163,6 +169,9 @@ def handle_callback_args(args, kwargs):
  if len(outputs) == 1:
  out0 = kwargs.get("output", args[0] if args else None)
  if not isinstance(out0, (list, tuple)):
+ # unless it was explicitly provided as a list, a single output
+ # sholuld be unwrapped. That ensures the return value of the
+ # callback is also not expected to be wrapped in a list.
  outputs = outputs[0]
 
  inputs = extract_callback_args(flat_args, kwargs, "inputs", Input)

tests/integration/callbacks/test_validation.py

@@ -144,3 +144,52 @@ def o2(i):
  dash_duo.start_server(app)
  dash_duo.wait_for_text_to_equal("#out1", "1: Hi")
  dash_duo.wait_for_text_to_equal("#out2", "2: Hi")
+
+
+@pytest.mark.parametrize("named_out", [True, False])
+@pytest.mark.parametrize("named_in", [True, False])
+@pytest.mark.parametrize("named_state", [True, False])
+def test_cbva004_named_args(named_out, named_in, named_state, dash_duo):
+ app = Dash(__name__)
+ app.layout = html.Div(
+ [
+ html.Div("Hi", id="in"),
+ html.Div("gh", id="state"),
+ html.Div(id="out1"),
+ html.Div(id="out2"),
+ ]
+ )
+
+ def make_args(*a):
+ args = []
+ kwargs = {}
+ names = ["output", "inputs", "state"]
+ flags = [named_out, named_in, named_state]
+ for ai, name, flag in zip(a, names, flags):
+ if flag:
+ kwargs[name] = ai
+ else:
+ args.append(ai)
+ return args, kwargs
+
+ args, kwargs = make_args(
+ Output("out1", "children"), Input("in", "children"), State("state", "children")
+ )
+
+ @app.callback(*args, **kwargs)
+ def o1(i, s):
+ return "1: " + i + s
+
+ args, kwargs = make_args(
+ [Output("out2", "children")],
+ [Input("in", "children")],
+ [State("state", "children")],
+ )
+
+ @app.callback(*args, **kwargs)
+ def o2(i, s):
+ return ("2: " + i + s,)
+
+ dash_duo.start_server(app)
+ dash_duo.wait_for_text_to_equal("#out1", "1: High")
+ dash_duo.wait_for_text_to_equal("#out2", "2: High")

CHANGELOG.md

@@ -3,14 +3,13 @@ All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
-### Changed
-- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
-
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
 
 ### Changed
-- [#1180](https://github.com/plotly/dash/pull/1180) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1180](https://github.com/plotly/dash/pull/1180) and [#1375](https://github.com/plotly/dash/pull/1375) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
+
 
 ## [1.14.0] - 2020-07-27
 ### Added

dash/dependencies.py

@@ -140,7 +140,13 @@ def __repr__(self):
 def extract_callback_args(args, kwargs, name, type_):
  """Extract arguments for callback from a name and type"""
  parameters = kwargs.get(name, [])
- if not parameters:
+ if parameters:
+ if not isinstance(parameters, (list, tuple)):
+ # accept a single item, not wrapped in a list, for any of the
+ # categories as a named arg (even though previously only output
+ # could be given unwrapped)
+ return [parameters]
+ else:
  while args and isinstance(args[0], type_):
  parameters.append(args.pop(0))
  return parameters
@@ -163,6 +169,9 @@ def handle_callback_args(args, kwargs):
  if len(outputs) == 1:
  out0 = kwargs.get("output", args[0] if args else None)
  if not isinstance(out0, (list, tuple)):
+ # unless it was explicitly provided as a list, a single output
+ # sholuld be unwrapped. That ensures the return value of the
+ # callback is also not expected to be wrapped in a list.
  outputs = outputs[0]
 
  inputs = extract_callback_args(flat_args, kwargs, "inputs", Input)

tests/integration/callbacks/test_validation.py

@@ -144,3 +144,52 @@ def o2(i):
  dash_duo.start_server(app)
  dash_duo.wait_for_text_to_equal("#out1", "1: Hi")
  dash_duo.wait_for_text_to_equal("#out2", "2: Hi")
+
+
+@pytest.mark.parametrize("named_out", [True, False])
+@pytest.mark.parametrize("named_in", [True, False])
+@pytest.mark.parametrize("named_state", [True, False])
+def test_cbva004_named_args(named_out, named_in, named_state, dash_duo):
+ app = Dash(__name__)
+ app.layout = html.Div(
+ [
+ html.Div("Hi", id="in"),
+ html.Div("gh", id="state"),
+ html.Div(id="out1"),
+ html.Div(id="out2"),
+ ]
+ )
+
+ def make_args(*a):
+ args = []
+ kwargs = {}
+ names = ["output", "inputs", "state"]
+ flags = [named_out, named_in, named_state]
+ for ai, name, flag in zip(a, names, flags):
+ if flag:
+ kwargs[name] = ai
+ else:
+ args.append(ai)
+ return args, kwargs
+
+ args, kwargs = make_args(
+ Output("out1", "children"), Input("in", "children"), State("state", "children")
+ )
+
+ @app.callback(*args, **kwargs)
+ def o1(i, s):
+ return "1: " + i + s
+
+ args, kwargs = make_args(
+ [Output("out2", "children")],
+ [Input("in", "children")],
+ [State("state", "children")],
+ )
+
+ @app.callback(*args, **kwargs)
+ def o2(i, s):
+ return ("2: " + i + s,)
+
+ dash_duo.start_server(app)
+ dash_duo.wait_for_text_to_equal("#out1", "1: High")
+ dash_duo.wait_for_text_to_equal("#out2", "2: High")

CHANGELOG.md

@@ -3,14 +3,13 @@ All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
-### Changed
-- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
-
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
 
 ### Changed
-- [#1180](https://github.com/plotly/dash/pull/1180) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1180](https://github.com/plotly/dash/pull/1180) and [#1375](https://github.com/plotly/dash/pull/1375) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
+
 
 ## [1.14.0] - 2020-07-27
 ### Added

dash/dependencies.py

@@ -140,7 +140,13 @@ def __repr__(self):
 def extract_callback_args(args, kwargs, name, type_):
  """Extract arguments for callback from a name and type"""
  parameters = kwargs.get(name, [])
- if not parameters:
+ if parameters:
+ if not isinstance(parameters, (list, tuple)):
+ # accept a single item, not wrapped in a list, for any of the
+ # categories as a named arg (even though previously only output
+ # could be given unwrapped)
+ return [parameters]
+ else:
  while args and isinstance(args[0], type_):
  parameters.append(args.pop(0))
  return parameters
@@ -163,6 +169,9 @@ def handle_callback_args(args, kwargs):
  if len(outputs) == 1:
  out0 = kwargs.get("output", args[0] if args else None)
  if not isinstance(out0, (list, tuple)):
+ # unless it was explicitly provided as a list, a single output
+ # sholuld be unwrapped. That ensures the return value of the
+ # callback is also not expected to be wrapped in a list.
  outputs = outputs[0]
 
  inputs = extract_callback_args(flat_args, kwargs, "inputs", Input)

tests/integration/callbacks/test_validation.py

@@ -144,3 +144,52 @@ def o2(i):
  dash_duo.start_server(app)
  dash_duo.wait_for_text_to_equal("#out1", "1: Hi")
  dash_duo.wait_for_text_to_equal("#out2", "2: Hi")
+
+
+@pytest.mark.parametrize("named_out", [True, False])
+@pytest.mark.parametrize("named_in", [True, False])
+@pytest.mark.parametrize("named_state", [True, False])
+def test_cbva004_named_args(named_out, named_in, named_state, dash_duo):
+ app = Dash(__name__)
+ app.layout = html.Div(
+ [
+ html.Div("Hi", id="in"),
+ html.Div("gh", id="state"),
+ html.Div(id="out1"),
+ html.Div(id="out2"),
+ ]
+ )
+
+ def make_args(*a):
+ args = []
+ kwargs = {}
+ names = ["output", "inputs", "state"]
+ flags = [named_out, named_in, named_state]
+ for ai, name, flag in zip(a, names, flags):
+ if flag:
+ kwargs[name] = ai
+ else:
+ args.append(ai)
+ return args, kwargs
+
+ args, kwargs = make_args(
+ Output("out1", "children"), Input("in", "children"), State("state", "children")
+ )
+
+ @app.callback(*args, **kwargs)
+ def o1(i, s):
+ return "1: " + i + s
+
+ args, kwargs = make_args(
+ [Output("out2", "children")],
+ [Input("in", "children")],
+ [State("state", "children")],
+ )
+
+ @app.callback(*args, **kwargs)
+ def o2(i, s):
+ return ("2: " + i + s,)
+
+ dash_duo.start_server(app)
+ dash_duo.wait_for_text_to_equal("#out1", "1: High")
+ dash_duo.wait_for_text_to_equal("#out2", "2: High")

CHANGELOG.md

@@ -3,14 +3,13 @@ All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
-### Changed
-- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
-
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
 
 ### Changed
-- [#1180](https://github.com/plotly/dash/pull/1180) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1180](https://github.com/plotly/dash/pull/1180) and [#1375](https://github.com/plotly/dash/pull/1375) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
+
 
 ## [1.14.0] - 2020-07-27
 ### Added

dash/dependencies.py

@@ -140,7 +140,13 @@ def __repr__(self):
 def extract_callback_args(args, kwargs, name, type_):
  """Extract arguments for callback from a name and type"""
  parameters = kwargs.get(name, [])
- if not parameters:
+ if parameters:
+ if not isinstance(parameters, (list, tuple)):
+ # accept a single item, not wrapped in a list, for any of the
+ # categories as a named arg (even though previously only output
+ # could be given unwrapped)
+ return [parameters]
+ else:
  while args and isinstance(args[0], type_):
  parameters.append(args.pop(0))
  return parameters
@@ -163,6 +169,9 @@ def handle_callback_args(args, kwargs):
  if len(outputs) == 1:
  out0 = kwargs.get("output", args[0] if args else None)
  if not isinstance(out0, (list, tuple)):
+ # unless it was explicitly provided as a list, a single output
+ # sholuld be unwrapped. That ensures the return value of the
+ # callback is also not expected to be wrapped in a list.
  outputs = outputs[0]
 
  inputs = extract_callback_args(flat_args, kwargs, "inputs", Input)

tests/integration/callbacks/test_validation.py

@@ -144,3 +144,52 @@ def o2(i):
  dash_duo.start_server(app)
  dash_duo.wait_for_text_to_equal("#out1", "1: Hi")
  dash_duo.wait_for_text_to_equal("#out2", "2: Hi")
+
+
+@pytest.mark.parametrize("named_out", [True, False])
+@pytest.mark.parametrize("named_in", [True, False])
+@pytest.mark.parametrize("named_state", [True, False])
+def test_cbva004_named_args(named_out, named_in, named_state, dash_duo):
+ app = Dash(__name__)
+ app.layout = html.Div(
+ [
+ html.Div("Hi", id="in"),
+ html.Div("gh", id="state"),
+ html.Div(id="out1"),
+ html.Div(id="out2"),
+ ]
+ )
+
+ def make_args(*a):
+ args = []
+ kwargs = {}
+ names = ["output", "inputs", "state"]
+ flags = [named_out, named_in, named_state]
+ for ai, name, flag in zip(a, names, flags):
+ if flag:
+ kwargs[name] = ai
+ else:
+ args.append(ai)
+ return args, kwargs
+
+ args, kwargs = make_args(
+ Output("out1", "children"), Input("in", "children"), State("state", "children")
+ )
+
+ @app.callback(*args, **kwargs)
+ def o1(i, s):
+ return "1: " + i + s
+
+ args, kwargs = make_args(
+ [Output("out2", "children")],
+ [Input("in", "children")],
+ [State("state", "children")],
+ )
+
+ @app.callback(*args, **kwargs)
+ def o2(i, s):
+ return ("2: " + i + s,)
+
+ dash_duo.start_server(app)
+ dash_duo.wait_for_text_to_equal("#out1", "1: High")
+ dash_duo.wait_for_text_to_equal("#out2", "2: High")

CHANGELOG.md

@@ -3,14 +3,13 @@ All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
-### Changed
-- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
-
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
 
 ### Changed
-- [#1180](https://github.com/plotly/dash/pull/1180) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1180](https://github.com/plotly/dash/pull/1180) and [#1375](https://github.com/plotly/dash/pull/1375) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
+
 
 ## [1.14.0] - 2020-07-27
 ### Added

dash/dependencies.py

@@ -140,7 +140,13 @@ def __repr__(self):
 def extract_callback_args(args, kwargs, name, type_):
  """Extract arguments for callback from a name and type"""
  parameters = kwargs.get(name, [])
- if not parameters:
+ if parameters:
+ if not isinstance(parameters, (list, tuple)):
+ # accept a single item, not wrapped in a list, for any of the
+ # categories as a named arg (even though previously only output
+ # could be given unwrapped)
+ return [parameters]
+ else:
  while args and isinstance(args[0], type_):
  parameters.append(args.pop(0))
  return parameters
@@ -163,6 +169,9 @@ def handle_callback_args(args, kwargs):
  if len(outputs) == 1:
  out0 = kwargs.get("output", args[0] if args else None)
  if not isinstance(out0, (list, tuple)):
+ # unless it was explicitly provided as a list, a single output
+ # sholuld be unwrapped. That ensures the return value of the
+ # callback is also not expected to be wrapped in a list.
  outputs = outputs[0]
 
  inputs = extract_callback_args(flat_args, kwargs, "inputs", Input)

tests/integration/callbacks/test_validation.py

@@ -144,3 +144,52 @@ def o2(i):
  dash_duo.start_server(app)
  dash_duo.wait_for_text_to_equal("#out1", "1: Hi")
  dash_duo.wait_for_text_to_equal("#out2", "2: Hi")
+
+
+@pytest.mark.parametrize("named_out", [True, False])
+@pytest.mark.parametrize("named_in", [True, False])
+@pytest.mark.parametrize("named_state", [True, False])
+def test_cbva004_named_args(named_out, named_in, named_state, dash_duo):
+ app = Dash(__name__)
+ app.layout = html.Div(
+ [
+ html.Div("Hi", id="in"),
+ html.Div("gh", id="state"),
+ html.Div(id="out1"),
+ html.Div(id="out2"),
+ ]
+ )
+
+ def make_args(*a):
+ args = []
+ kwargs = {}
+ names = ["output", "inputs", "state"]
+ flags = [named_out, named_in, named_state]
+ for ai, name, flag in zip(a, names, flags):
+ if flag:
+ kwargs[name] = ai
+ else:
+ args.append(ai)
+ return args, kwargs
+
+ args, kwargs = make_args(
+ Output("out1", "children"), Input("in", "children"), State("state", "children")
+ )
+
+ @app.callback(*args, **kwargs)
+ def o1(i, s):
+ return "1: " + i + s
+
+ args, kwargs = make_args(
+ [Output("out2", "children")],
+ [Input("in", "children")],
+ [State("state", "children")],
+ )
+
+ @app.callback(*args, **kwargs)
+ def o2(i, s):
+ return ("2: " + i + s,)
+
+ dash_duo.start_server(app)
+ dash_duo.wait_for_text_to_equal("#out1", "1: High")
+ dash_duo.wait_for_text_to_equal("#out2", "2: High")

CHANGELOG.md

@@ -3,14 +3,13 @@ All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
-### Changed
-- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
-
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
 
 ### Changed
-- [#1180](https://github.com/plotly/dash/pull/1180) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1180](https://github.com/plotly/dash/pull/1180) and [#1375](https://github.com/plotly/dash/pull/1375) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
+
 
 ## [1.14.0] - 2020-07-27
 ### Added

dash/dependencies.py

@@ -140,7 +140,13 @@ def __repr__(self):
 def extract_callback_args(args, kwargs, name, type_):
  """Extract arguments for callback from a name and type"""
  parameters = kwargs.get(name, [])
- if not parameters:
+ if parameters:
+ if not isinstance(parameters, (list, tuple)):
+ # accept a single item, not wrapped in a list, for any of the
+ # categories as a named arg (even though previously only output
+ # could be given unwrapped)
+ return [parameters]
+ else:
  while args and isinstance(args[0], type_):
  parameters.append(args.pop(0))
  return parameters
@@ -163,6 +169,9 @@ def handle_callback_args(args, kwargs):
  if len(outputs) == 1:
  out0 = kwargs.get("output", args[0] if args else None)
  if not isinstance(out0, (list, tuple)):
+ # unless it was explicitly provided as a list, a single output
+ # sholuld be unwrapped. That ensures the return value of the
+ # callback is also not expected to be wrapped in a list.
  outputs = outputs[0]
 
  inputs = extract_callback_args(flat_args, kwargs, "inputs", Input)

tests/integration/callbacks/test_validation.py

@@ -144,3 +144,52 @@ def o2(i):
  dash_duo.start_server(app)
  dash_duo.wait_for_text_to_equal("#out1", "1: Hi")
  dash_duo.wait_for_text_to_equal("#out2", "2: Hi")
+
+
+@pytest.mark.parametrize("named_out", [True, False])
+@pytest.mark.parametrize("named_in", [True, False])
+@pytest.mark.parametrize("named_state", [True, False])
+def test_cbva004_named_args(named_out, named_in, named_state, dash_duo):
+ app = Dash(__name__)
+ app.layout = html.Div(
+ [
+ html.Div("Hi", id="in"),
+ html.Div("gh", id="state"),
+ html.Div(id="out1"),
+ html.Div(id="out2"),
+ ]
+ )
+
+ def make_args(*a):
+ args = []
+ kwargs = {}
+ names = ["output", "inputs", "state"]
+ flags = [named_out, named_in, named_state]
+ for ai, name, flag in zip(a, names, flags):
+ if flag:
+ kwargs[name] = ai
+ else:
+ args.append(ai)
+ return args, kwargs
+
+ args, kwargs = make_args(
+ Output("out1", "children"), Input("in", "children"), State("state", "children")
+ )
+
+ @app.callback(*args, **kwargs)
+ def o1(i, s):
+ return "1: " + i + s
+
+ args, kwargs = make_args(
+ [Output("out2", "children")],
+ [Input("in", "children")],
+ [State("state", "children")],
+ )
+
+ @app.callback(*args, **kwargs)
+ def o2(i, s):
+ return ("2: " + i + s,)
+
+ dash_duo.start_server(app)
+ dash_duo.wait_for_text_to_equal("#out1", "1: High")
+ dash_duo.wait_for_text_to_equal("#out2", "2: High")

CHANGELOG.md

@@ -3,14 +3,13 @@ All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
-### Changed
-- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
-
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
 
 ### Changed
-- [#1180](https://github.com/plotly/dash/pull/1180) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1180](https://github.com/plotly/dash/pull/1180) and [#1375](https://github.com/plotly/dash/pull/1375) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
+
 
 ## [1.14.0] - 2020-07-27
 ### Added

dash/dependencies.py

@@ -140,7 +140,13 @@ def __repr__(self):
 def extract_callback_args(args, kwargs, name, type_):
  """Extract arguments for callback from a name and type"""
  parameters = kwargs.get(name, [])
- if not parameters:
+ if parameters:
+ if not isinstance(parameters, (list, tuple)):
+ # accept a single item, not wrapped in a list, for any of the
+ # categories as a named arg (even though previously only output
+ # could be given unwrapped)
+ return [parameters]
+ else:
  while args and isinstance(args[0], type_):
  parameters.append(args.pop(0))
  return parameters
@@ -163,6 +169,9 @@ def handle_callback_args(args, kwargs):
  if len(outputs) == 1:
  out0 = kwargs.get("output", args[0] if args else None)
  if not isinstance(out0, (list, tuple)):
+ # unless it was explicitly provided as a list, a single output
+ # sholuld be unwrapped. That ensures the return value of the
+ # callback is also not expected to be wrapped in a list.
  outputs = outputs[0]
 
  inputs = extract_callback_args(flat_args, kwargs, "inputs", Input)

tests/integration/callbacks/test_validation.py

@@ -144,3 +144,52 @@ def o2(i):
  dash_duo.start_server(app)
  dash_duo.wait_for_text_to_equal("#out1", "1: Hi")
  dash_duo.wait_for_text_to_equal("#out2", "2: Hi")
+
+
+@pytest.mark.parametrize("named_out", [True, False])
+@pytest.mark.parametrize("named_in", [True, False])
+@pytest.mark.parametrize("named_state", [True, False])
+def test_cbva004_named_args(named_out, named_in, named_state, dash_duo):
+ app = Dash(__name__)
+ app.layout = html.Div(
+ [
+ html.Div("Hi", id="in"),
+ html.Div("gh", id="state"),
+ html.Div(id="out1"),
+ html.Div(id="out2"),
+ ]
+ )
+
+ def make_args(*a):
+ args = []
+ kwargs = {}
+ names = ["output", "inputs", "state"]
+ flags = [named_out, named_in, named_state]
+ for ai, name, flag in zip(a, names, flags):
+ if flag:
+ kwargs[name] = ai
+ else:
+ args.append(ai)
+ return args, kwargs
+
+ args, kwargs = make_args(
+ Output("out1", "children"), Input("in", "children"), State("state", "children")
+ )
+
+ @app.callback(*args, **kwargs)
+ def o1(i, s):
+ return "1: " + i + s
+
+ args, kwargs = make_args(
+ [Output("out2", "children")],
+ [Input("in", "children")],
+ [State("state", "children")],
+ )
+
+ @app.callback(*args, **kwargs)
+ def o2(i, s):
+ return ("2: " + i + s,)
+
+ dash_duo.start_server(app)
+ dash_duo.wait_for_text_to_equal("#out1", "1: High")
+ dash_duo.wait_for_text_to_equal("#out2", "2: High")

CHANGELOG.md

@@ -3,14 +3,13 @@ All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
-### Changed
-- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
-
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
 
 ### Changed
-- [#1180](https://github.com/plotly/dash/pull/1180) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1180](https://github.com/plotly/dash/pull/1180) and [#1375](https://github.com/plotly/dash/pull/1375) `Input`, `Output`, and `State` in callback definitions don't need to be in lists. You still need to provide `Output` items first, then `Input` items, then `State`, and the list form is still supported. In particular, if you want to return a single output item wrapped in a length-1 list, you should still wrap the `Output` in a list. This can be useful for procedurally-generated callbacks.
+- [#1368](https://github.com/plotly/dash/pull/1368) Updated pytest to v6.0.1. To avoid deprecation warnings, this also updated pytest-sugar to 0.9.4 and pytest-mock to 3.2.0. The pytest-mock update only effects python >= 3.0. Pytest-mock remains pinned at 2.0.0 for python == 2.7.
+
 
 ## [1.14.0] - 2020-07-27
 ### Added

dash/dependencies.py

@@ -140,7 +140,13 @@ def __repr__(self):
 def extract_callback_args(args, kwargs, name, type_):
  """Extract arguments for callback from a name and type"""
  parameters = kwargs.get(name, [])
- if not parameters:
+ if parameters:
+ if not isinstance(parameters, (list, tuple)):
+ # accept a single item, not wrapped in a list, for any of the
+ # categories as a named arg (even though previously only output
+ # could be given unwrapped)
+ return [parameters]
+ else:
  while args and isinstance(args[0], type_):
  parameters.append(args.pop(0))
  return parameters
@@ -163,6 +169,9 @@ def handle_callback_args(args, kwargs):
  if len(outputs) == 1:
  out0 = kwargs.get("output", args[0] if args else None)
  if not isinstance(out0, (list, tuple)):
+ # unless it was explicitly provided as a list, a single output
+ # sholuld be unwrapped. That ensures the return value of the
+ # callback is also not expected to be wrapped in a list.
  outputs = outputs[0]
 
  inputs = extract_callback_args(flat_args, kwargs, "inputs", Input)

tests/integration/callbacks/test_validation.py

@@ -144,3 +144,52 @@ def o2(i):
  dash_duo.start_server(app)
  dash_duo.wait_for_text_to_equal("#out1", "1: Hi")
  dash_duo.wait_for_text_to_equal("#out2", "2: Hi")
+
+
+@pytest.mark.parametrize("named_out", [True, False])
+@pytest.mark.parametrize("named_in", [True, False])
+@pytest.mark.parametrize("named_state", [True, False])
+def test_cbva004_named_args(named_out, named_in, named_state, dash_duo):
+ app = Dash(__name__)
+ app.layout = html.Div(
+ [
+ html.Div("Hi", id="in"),
+ html.Div("gh", id="state"),
+ html.Div(id="out1"),
+ html.Div(id="out2"),
+ ]
+ )
+
+ def make_args(*a):
+ args = []
+ kwargs = {}
+ names = ["output", "inputs", "state"]
+ flags = [named_out, named_in, named_state]
+ for ai, name, flag in zip(a, names, flags):
+ if flag:
+ kwargs[name] = ai
+ else:
+ args.append(ai)
+ return args, kwargs
+
+ args, kwargs = make_args(
+ Output("out1", "children"), Input("in", "children"), State("state", "children")
+ )
+
+ @app.callback(*args, **kwargs)
+ def o1(i, s):
+ return "1: " + i + s
+
+ args, kwargs = make_args(
+ [Output("out2", "children")],
+ [Input("in", "children")],
+ [State("state", "children")],
+ )
+
+ @app.callback(*args, **kwargs)
+ def o2(i, s):
+ return ("2: " + i + s,)
+
+ dash_duo.start_server(app)
+ dash_duo.wait_for_text_to_equal("#out1", "1: High")
+ dash_duo.wait_for_text_to_equal("#out2", "2: High")