explicitize args in component meta

Author: T4rk1n

dash/development/_py_components_generation.py

@@ -24,7 +24,7 @@
 import typing  # noqa: F401
 import numbers # noqa: F401
 from typing_extensions import TypedDict, NotRequired, Literal # noqa: F401
-from dash.development.base_component import Component, _explicitize_args
+from dash.development.base_component import Component
 try:
     from dash.development.base_component import ComponentType # noqa: F401
 except ImportError:
@@ -80,7 +80,8 @@ def generate_class_string(
     _namespace = '{namespace}'
     _type = '{typename}'
 {shapes}
-    @_explicitize_args
+    _explicitize_dash_init = True
+
     def __init__(
         self,
         {default_argtext}

dash/development/base_component.py

@@ -51,13 +51,12 @@ class ComponentMeta(abc.ABCMeta):
 
     # pylint: disable=arguments-differ
     def __new__(mcs, name, bases, attributes):
-        component = abc.ABCMeta.__new__(mcs, name, bases, attributes)
         module = attributes["__module__"].split(".")[0]
         if name == "Component" or module == "builtins":
             # Don't do the base component
             # and the components loaded dynamically by load_component
             # as it doesn't have the namespace.
-            return component
+            return abc.ABCMeta.__new__(mcs, name, bases, attributes)
 
         _namespace = attributes.get("_namespace", module)
         ComponentRegistry.namespace_to_package[_namespace] = module
@@ -66,7 +65,13 @@ def __new__(mcs, name, bases, attributes):
             "_children_props"
         )
 
-        return component
+        if attributes.get("_explicitize_dash_init", False):
+            # We only want to patch the new generated component without
+            # the `@_explicitize_args` decorator for mypy support
+            # See issue: https://github.com/plotly/dash/issues/3226
+            attributes["__init__"] = _explicitize_args(attributes["__init__"])
+
+        return abc.ABCMeta.__new__(mcs, name, bases, attributes)
 
 
 def is_number(s):
@@ -435,6 +440,8 @@ def _validate_deprecation(self):
 
 ComponentType = typing.TypeVar("ComponentType", bound=Component)
 
+ComponentTemplate = typing.TypeVar("ComponentTemplate")
+
 
 # This wrapper adds an argument given to generated Component.__init__
 # with the actual given parameters by the user as a list of string.