Custom typing generator

CHANGELOG.md

@@ -4,6 +4,13 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [3.0.0-rc2] - UNRELEASED
 
+## Added
+
+- [#3152](https://github.com/plotly/dash/pull/3152) Custom Python prop typing for component library.
+  - Added `-t`, `--custom-typing-module` argument to `dash-generate-components` CLI, default to `dash_prop_typing` and can contains definitions in variables:
+    - `custom_imports: dict[ComponentName, list[str]]` import statement to be copied at the top of the component class definition.
+    - `custom_props: dict[ComponentName, dict[PropName, function]]` for custom props. The function signature is: `def generate_type(type_info, component_name, prop_name) -> str`
+
 ## Fixed
 
 - [#3142](https://github.com/plotly/dash/pull/3142) Fix typing generation for id and dates props.

components/dash-core-components/dash_prop_typing.py

@@ -0,0 +1,40 @@
+# This file is automatically loaded on build time to generate types.
+
+def generate_plotly_figure(*_):
+    return "typing.Union[Figure, dict]"
+
+
+def generate_datetime_prop(array=False):
+
+    def generator(*_):
+        datetime_type = "typing.Union[str, datetime.datetime]"
+        if array:
+            datetime_type = f"typing.Sequence[{datetime_type}]"
+        return datetime_type
+
+    return generator
+
+
+custom_imports = {
+    "Graph": ["from plotly.graph_objects import Figure"],
+    "DatePickerRange": ["import datetime"],
+    "DatePickerSingle": ["import datetime"],
+}
+
+custom_props = {
+    "Graph": {"figure": generate_plotly_figure},
+    "DatePickerRange": {
+        "start_date": generate_datetime_prop(),
+        "end_date": generate_datetime_prop(),
+        "min_date_allowed": generate_datetime_prop(),
+        "max_date_allowed": generate_datetime_prop(),
+        "disabled_days": generate_datetime_prop(True),
+    },
+    "DatePickerSingle": {
+        "date": generate_datetime_prop(),
+        "min_date_allowed": generate_datetime_prop(),
+        "max_date_allowed": generate_datetime_prop(),
+        "disabled_days": generate_datetime_prop(True),
+        "initial_visible_month": generate_datetime_prop(),
+    },
+}

dash/dash.py

@@ -16,7 +16,7 @@
 import base64
 import traceback
 from urllib.parse import urlparse
-from typing import Any, Callable, Dict, Optional, Union, List
+from typing import Any, Callable, Dict, Optional, Union, Sequence
 
 import flask
 
@@ -397,14 +397,14 @@ def __init__(  # pylint: disable=too-many-statements
         routes_pathname_prefix: Optional[str] = None,
         serve_locally: bool = True,
         compress: Optional[bool] = None,
-        meta_tags: Optional[List[Dict[str, Any]]] = None,
+        meta_tags: Optional[Sequence[Dict[str, Any]]] = None,
         index_string: str = _default_index,
-        external_scripts: Optional[List[Union[str, Dict[str, Any]]]] = None,
-        external_stylesheets: Optional[List[Union[str, Dict[str, Any]]]] = None,
+        external_scripts: Optional[Sequence[Union[str, Dict[str, Any]]]] = None,
+        external_stylesheets: Optional[Sequence[Union[str, Dict[str, Any]]]] = None,
         suppress_callback_exceptions: Optional[bool] = None,
         prevent_initial_callbacks: bool = False,
         show_undo_redo: bool = False,
-        extra_hot_reload_paths: Optional[List[str]] = None,
+        extra_hot_reload_paths: Optional[Sequence[str]] = None,
         plugins: Optional[list] = None,
         title: str = "Dash",
         update_title: str = "Updating...",

dash/development/_py_components_generation.py

@@ -10,7 +10,12 @@
 from dash.exceptions import NonExistentEventException
 from ._all_keywords import python_keywords
 from ._collect_nodes import collect_nodes, filter_base_nodes
-from ._py_prop_typing import get_prop_typing, shapes, custom_imports
+from ._py_prop_typing import (
+    get_custom_props,
+    get_prop_typing,
+    shapes,
+    get_custom_imports,
+)
 from .base_component import Component, ComponentType
 
 import_string = """# AUTO GENERATED FILE - DO NOT EDIT
@@ -36,6 +41,7 @@ def generate_class_string(
     namespace,
     prop_reorder_exceptions=None,
     max_props=None,
+    custom_typing_module=None,
 ):
     """Dynamically generate class strings to have nicely formatted docstrings,
     keyword arguments, and repr.
@@ -162,7 +168,14 @@ def __init__(
 
         type_name = type_info.get("name")
 
-        typed = get_prop_typing(type_name, typename, prop_key, type_info, namespace)
+        custom_props = get_custom_props(custom_typing_module)
+        typed = get_prop_typing(
+            type_name,
+            typename,
+            prop_key,
+            type_info,
+            custom_props=custom_props,
+        )
 
         arg_value = f"{prop_key}: typing.Optional[{typed}] = None"
 
@@ -208,6 +221,7 @@ def generate_class_file(
     namespace,
     prop_reorder_exceptions=None,
     max_props=None,
+    custom_typing_module="dash_prop_typing",
 ):
     """Generate a Python class file (.py) given a class string.
     Parameters
@@ -223,10 +237,16 @@ def generate_class_file(
     imports = import_string
 
     class_string = generate_class_string(
-        typename, props, description, namespace, prop_reorder_exceptions, max_props
+        typename,
+        props,
+        description,
+        namespace,
+        prop_reorder_exceptions,
+        max_props,
+        custom_typing_module,
     )
 
-    custom_imp = custom_imports[namespace][typename]
+    custom_imp = get_custom_imports(custom_typing_module).get(typename)
     if custom_imp:
         imports += "\n".join(custom_imp)
         imports += "\n\n"

dash/development/_py_prop_typing.py

@@ -2,6 +2,7 @@
 import json
 import string
 import textwrap
+import importlib
 
 import stringcase
 
@@ -15,6 +16,24 @@
 custom_imports = collections.defaultdict(lambda: collections.defaultdict(list))
 
 
+def _get_custom(module_name, prop, default):
+    if not module_name:
+        return default
+    try:
+        module = importlib.import_module(module_name)
+        return getattr(module, prop, default)
+    except ImportError:
+        return default
+
+
+def get_custom_imports(module_name):
+    return _get_custom(module_name, "custom_imports", {})
+
+
+def get_custom_props(module_name):
+    return _get_custom(module_name, "custom_props", {})
+
+
 def _clean_key(key):
     k = ""
     for ch in key:
@@ -118,17 +137,18 @@ def generate_enum(type_info, *_):
 
 
 def get_prop_typing(
-    type_name: str, component_name: str, prop_name: str, type_info, namespace=None
+    type_name: str,
+    component_name: str,
+    prop_name: str,
+    type_info,
+    custom_props=None,
 ):
     if prop_name == "id":
         # Id is always the same either a string or a dict for pattern matching.
         return "typing.Union[str, dict]"
 
-    if namespace:
-        # Only check the namespace once
-        special = (
-            special_cases.get(namespace, {}).get(component_name, {}).get(prop_name)
-        )
+    if custom_props:
+        special = custom_props.get(component_name, {}).get(prop_name)
         if special:
             return special(type_info, component_name, prop_name)
 
@@ -158,27 +178,6 @@ def generator(*_):
     return generator
 
 
-special_cases = {
-    "dash_core_components": {
-        "Graph": {"figure": generate_plotly_figure},
-        "DatePickerRange": {
-            "start_date": generate_datetime_prop("DatePickerRange"),
-            "end_date": generate_datetime_prop("DatePickerRange"),
-            "min_date_allowed": generate_datetime_prop("DatePickerRange"),
-            "max_date_allowed": generate_datetime_prop("DatePickerRange"),
-            "disabled_days": generate_datetime_prop("DatePickerRange", True),
-        },
-        "DatePickerSingle": {
-            "date": generate_datetime_prop("DatePickerSingle"),
-            "min_date_allowed": generate_datetime_prop("DatePickerSingle"),
-            "max_date_allowed": generate_datetime_prop("DatePickerSingle"),
-            "disabled_days": generate_datetime_prop("DatePickerSingle", True),
-            "initial_visible_month": generate_datetime_prop("DatePickerSingle"),
-        },
-    }
-}
-
-
 PROP_TYPING = {
     "array": generate_type("typing.Sequence"),
     "arrayOf": generate_array_of,

dash/development/component_generator.py

@@ -50,6 +50,7 @@ def generate_components(
     metadata=None,
     keep_prop_order=None,
     max_props=None,
+    custom_typing_module=None,
 ):
 
     project_shortname = project_shortname.replace("-", "_").rstrip("/\\")
@@ -99,7 +100,9 @@ def generate_components(
 
         metadata = safe_json_loads(out.decode("utf-8"))
 
-    py_generator_kwargs = {}
+    py_generator_kwargs = {
+        "custom_typing_module": custom_typing_module,
+    }
     if keep_prop_order is not None:
         keep_prop_order = [
             component.strip(" ") for component in keep_prop_order.split(",")
@@ -239,10 +242,22 @@ def component_build_arg_parser():
         "but you may also want to reduce further for improved readability at the "
         "expense of auto-completion for the later props. Use 0 to include all props.",
     )
+    parser.add_argument(
+        "-t",
+        "--custom-typing-module",
+        type=str,
+        default="dash_prop_typing",
+        help=" Module containing custom typing definition for components."
+        "Can contains two variables:\n"
+        " - custom_imports: dict[ComponentName, list[str]].\n"
+        " - custom_props: dict[ComponentName, dict[PropName, function]].\n",
+    )
     return parser
 
 
 def cli():
+    # Add current path for loading modules.
+    sys.path.insert(0, ".")
     args = component_build_arg_parser().parse_args()
     generate_components(
         args.components_source,
@@ -256,6 +271,7 @@ def cli():
         jlprefix=args.jl_prefix,
         keep_prop_order=args.keep_prop_order,
         max_props=args.max_props,
+        custom_typing_module=args.custom_typing_module,
     )