Implement 'auto' id namespacing for shiny's Module()

Depends on posit-dev/py-htmltools#24

examples/moduleapp/app.py

@@ -1,23 +1,20 @@
-from typing import Callable
 from shiny import *
-from shiny.modules import *
-
 
 # ============================================================
 # Counter module
 # ============================================================
-def counter_ui(
-    ns: Callable[[str], str], label: str = "Increment counter"
-) -> ui.TagChildArg:
+def counter_ui(label: str = "Increment counter") -> ui.TagChildArg:
     return ui.div(
         {"style": "border: 1px solid #ccc; border-radius: 5px; margin: 5px 0;"},
         ui.h2("This is " + label),
-        ui.input_action_button(id=ns("button"), label=label),
-        ui.output_text_verbatim(id=ns("out")),
+        ui.input_action_button(id="button", label=label),
+        ui.output_text_verbatim(id="out"),
     )
 
 
-def counter_server(input: ModuleInputs, output: ModuleOutputs, session: ModuleSession):
+def counter_server(
+    input: Inputs, output: Outputs, session: Session, counter0: reactive.Calc_[int]
+) -> int:
     count: reactive.Value[int] = reactive.Value(0)
 
     @reactive.Effect()
@@ -30,6 +27,13 @@ def _():
     def out() -> str:
         return f"Click count is {count()}"
 
+    @reactive.Effect()
+    def _():
+        print("Clicked global counter", counter0())
+        # print("Clicked global counter", inputs.counter0())
+
+    return 1
+
 
 counter_module = Module(counter_ui, counter_server)
 
@@ -38,14 +42,19 @@ def out() -> str:
 # App that uses module
 # =============================================================================
 app_ui = ui.page_fluid(
-    counter_module.ui("counter1", "Counter 1"),
+    counter_module.ui("counter1", label="Counter 1"),
     counter_module.ui("counter2", "Counter 2"),
+    ui.input_action_button("counter0", "Print global counter"),
 )
 
 
-def server(input: Inputs, output: Outputs, session: Session):
-    counter_module.server("counter1")
-    counter_module.server("counter2")
+def server(inputs: Inputs, output: Outputs, sess: Session):
+    @reactive.Calc()
+    def counter0():
+        return inputs.counter0()
+
+    counter_module.server("counter1", counter0=counter0)
+    counter_module.server("counter2", counter0=counter0)
 
 
 app = App(app_ui, server)

shiny/__init__.py

@@ -12,6 +12,7 @@
 from ._app import App
 from ._decorators import event
 from ._validation import req
+from .modules import Module
 
 if _is_pyodide:
     # In pyodide, avoid importing _main because it imports packages that aren't
@@ -21,7 +22,6 @@
     from ._main import run_app
 
 # User-facing submodules that should *not* be available on `from shiny import *`
-from . import modules
 from . import types
 
 # N.B.: we intentionally don't import 'developer-facing' submodules (e.g.,
@@ -41,6 +41,8 @@
     "event",
     # _main.py
     "run_app",
+    # _modules.py
+    "Module",
     # _render.py
     "render_text",
     "render_plot",

shiny/_namespaces.py

@@ -0,0 +1,97 @@
+__all__ = ("namespace_context", "namespaced_id")
+
+from contextlib import contextmanager
+from contextvars import ContextVar, Token
+import functools
+
+from typing import Awaitable, Union, Optional, TypeVar, Callable, cast
+
+from shiny.types import MISSING, MISSING_TYPE
+
+from ._utils import is_async_callable
+
+_current_namespace: ContextVar[Optional[str]] = ContextVar(
+    "current_namespace", default=None
+)
+
+
+def get_current_namespace() -> Optional[str]:
+    """
+    Get the current namespace.
+    """
+    return _current_namespace.get()
+
+
+@contextmanager
+def namespace_context(ns: str):
+    """
+    Set a namespace for the duration of the context.
+    """
+    token: Token[Union[str, None]] = _current_namespace.set(ns)
+    try:
+        yield
+    finally:
+        _current_namespace.reset(token)
+
+
+def namespaced_id(id: str, ns: Union[str, MISSING_TYPE, None] = MISSING) -> str:
+    """
+    Namespace an ID based on the current ``Module()``'s namespace.
+
+    Parameters
+    ----------
+    id
+        The ID to namespace.
+
+    Warning
+    -------
+    This is only provided so that htmltools can use it to namespace ids within a
+    ``Module()`` UI function.
+    """
+    if isinstance(ns, MISSING_TYPE):
+        ns = _current_namespace.get()
+
+    if ns is None:
+        return id
+    else:
+        return ns + "_" + id
+
+
+T = TypeVar("T")
+
+
+def add_namespace(
+    fn: Union[Callable[..., T], Callable[..., Awaitable[T]]],
+    ns: Union[str, MISSING_TYPE, None] = MISSING,
+) -> Union[Callable[..., T], Callable[..., Awaitable[T]]]:
+    """
+    Modify a function to use the **current** namespace when it executes.
+
+    Note
+    ----
+    This is useful for marking user supplied functions to use the **current** namespace
+    when they execute **later on**.
+    """
+
+    if isinstance(ns, MISSING_TYPE):
+        ns = _current_namespace.get()
+
+    if ns is None:
+        return fn
+
+    if is_async_callable(fn):
+
+        @functools.wraps(fn)
+        async def wrapper(*args: object, **kwargs: object) -> T:
+            with namespace_context(ns):
+                return await fn(*args, **kwargs)
+
+    else:
+        fn = cast(Callable[..., T], fn)
+
+        @functools.wraps(fn)
+        def wrapper(*args: object, **kwargs: object) -> T:
+            with namespace_context(ns):
+                return fn(*args, **kwargs)
+
+    return wrapper

shiny/examples/Module/app.py

@@ -1,23 +1,20 @@
 from typing import Callable
 from shiny import *
-from shiny.modules import *
 
 
 # ============================================================
 # Counter module
 # ============================================================
-def counter_ui(
-    ns: Callable[[str], str], label: str = "Increment counter"
-) -> ui.TagChildArg:
+def counter_ui(label: str = "Increment counter") -> ui.TagChildArg:
     return ui.div(
         {"style": "border: 1px solid #ccc; border-radius: 5px; margin: 5px 0;"},
         ui.h2("This is " + label),
-        ui.input_action_button(id=ns("button"), label=label),
-        ui.output_text_verbatim(id=ns("out")),
+        ui.input_action_button(id="button", label=label),
+        ui.output_text_verbatim(id="out"),
     )
 
 
-def counter_server(input: ModuleInputs, output: ModuleOutputs, session: ModuleSession):
+def counter_server(input: Inputs, output: Outputs, session: Session):
     count: reactive.Value[int] = reactive.Value(0)
 
     @reactive.Effect()