Align dpd callback signature to Dash one (no need to group Outputs, Inputs and States into list). (#322)

Co-authored-by: GFJ138 <sebastien.dementen@engie.com>

Author: sdementen

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes should be documented in this file.
 
+## [dev] - TBD
+
+Align dpd callback signature to Dash one (no need to group Outputs, Inputs and States into list).  
+
 ## [1.6.1] - 2021-02-06
 
 Added a stub for `use_dash_dispatch` for backwards compatibility.

django_plotly_dash/dash_wrapper.py

@@ -30,7 +30,7 @@
 import warnings
 
 import dash
-from dash import Dash
+from dash import Dash, dependencies
 from dash._utils import split_callback_id, inputs_to_dict
 
 from flask import Flask
@@ -320,7 +320,7 @@ def get_expanded_arguments(func, inputs, state):
 
         return expanded
 
-    def callback(self, output, inputs=None, state=None, events=None):
+    def callback(self, *_args, **_kwargs):
         '''Form a callback function by wrapping, in the same way as the underlying Dash application would
         but handling extra arguments provided by dpd.
 
@@ -331,10 +331,15 @@ def callback(self, output, inputs=None, state=None, events=None):
         Otherwise, take all arguments beyond the one provided by Dash (based on the Inputs/States provided).
 
         '''
+
+        output, inputs, state, prevent_initial_call = dependencies.handle_callback_args(
+            _args, _kwargs
+        )
+
         callback_set = {'output': output,
-                        'inputs': inputs or [],
-                        'state': state or [],
-                        'events': events or []}
+                        'inputs': inputs,
+                        'state': state,
+                        'prevent_initial_call': prevent_initial_call}
 
         def wrap_func(func):
             self._callback_sets.append((callback_set, func))
@@ -348,12 +353,17 @@ def wrap_func(func):
 
     expanded_callback = callback
 
-    def clientside_callback(self, clientside_function, output, inputs=None, state=None):
+    def clientside_callback(self, clientside_function,  *_args, **_kwargs):
         'Form a callback function by wrapping, in the same way as the underlying Dash application would'
+        output, inputs, state, prevent_initial_call = dependencies.handle_callback_args(
+            _args, _kwargs
+        )
+
         callback_set = { 'clientside_function': clientside_function,
                          'output': output,
-                         'inputs': inputs and inputs or dict(),
-                         'state': state and state or dict() }
+                         'inputs': inputs,
+                         'state': state,
+                         'prevent_initial_call': prevent_initial_call}
 
         self._clientside_callback_sets.append(callback_set)
 
@@ -589,7 +599,7 @@ def _fix_callback_item(self, item):
         item.component_id = self._fix_id(item.component_id)
         return item
 
-    def callback(self, output, inputs=[], state=[], events=[]): # pylint: disable=dangerous-default-value
+    def callback(self, output, inputs, state, prevent_initial_call):
         'Invoke callback, adjusting variable names as needed'
 
         if isinstance(output, (list, tuple)):
@@ -599,9 +609,10 @@ def callback(self, output, inputs=[], state=[], events=[]): # pylint: disable=da
 
         return super().callback(fixed_outputs,
                                 [self._fix_callback_item(x) for x in inputs],
-                                [self._fix_callback_item(x) for x in state])
+                                [self._fix_callback_item(x) for x in state],
+                                prevent_initial_call=prevent_initial_call)
 
-    def clientside_callback(self, clientside_function, output, inputs=[], state=[]): # pylint: disable=dangerous-default-value
+    def clientside_callback(self, clientside_function, output, inputs, state, prevent_initial_call): # pylint: disable=dangerous-default-value
         'Invoke callback, adjusting variable names as needed'
 
         if isinstance(output, (list, tuple)):
@@ -612,7 +623,8 @@ def clientside_callback(self, clientside_function, output, inputs=[], state=[]):
         return super().clientside_callback(clientside_function,
                                            fixed_outputs,
                                            [self._fix_callback_item(x) for x in inputs],
-                                           [self._fix_callback_item(x) for x in state])
+                                           [self._fix_callback_item(x) for x in state],
+                                           prevent_initial_call=prevent_initial_call)
 
     #pylint: disable=too-many-locals
     def dispatch_with_args(self, body, argMap):

django_plotly_dash/tests.py

@@ -32,7 +32,7 @@
 
 import pytest
 # pylint: disable=bare-except
-from dash.dependencies import Input
+from dash.dependencies import Input, State, Output
 from django.urls import reverse
 
 from django_plotly_dash import DjangoDash
@@ -202,6 +202,56 @@ def test_dash_stateful_app_client_contract(client):
     assert DashApp.objects.get(instance_name="Some name").current_state() == final_state
 
 
+
+def test_dash_callback_arguments():
+    'Test the flexibility of the callback arguments order (handling of inputs/outputs/states)'
+
+    # create a DjangoDash
+    ddash = DjangoDash(name="DashCallbackArguments")
+
+    # add a callback with the new flexible order of dependencies
+    @ddash.callback(
+        Output("one", "foo"),
+        Output("two", "foo"),
+        Input("one", "baz"),
+        Input("two", "baz"),
+        Input("three", "baz"),
+        State("one", "bil"),
+    )
+    def new():
+        pass
+
+    # add a callback with the old/classical flexible order of dependencies
+    @ddash.callback(
+        [Output("one", "foo"),
+         Output("two", "foo")],
+        [Input("one", "baz"),
+         Input("two", "baz"),
+         Input("three", "baz")],
+        [State("one", "bil")]
+    )
+    def old():
+        pass
+
+    assert ddash._callback_sets == [({'inputs': [Input("one", "baz"),
+                                                 Input("two", "baz"),
+                                                 Input("three", "baz"), ],
+                                      'output': [Output("one", "foo"),
+                                                 Output("two", "foo")],
+                                      'prevent_initial_call': None,
+                                      'state': [State("one", "bil"), ]},
+                                     new),
+                                    ({'inputs': [Input("one", "baz"),
+                                                 Input("two", "baz"),
+                                                 Input("three", "baz"), ],
+                                      'output': [Output("one", "foo"),
+                                                 Output("two", "foo")],
+                                      'prevent_initial_call': None,
+                                      'state': [State("one", "bil"), ]},
+                                     old)
+                                    ]
+
+
 def test_util_error_cases(settings):
     'Test handling of missing settings'