Use contextvars to show public function names in log messages

Instead of exposing internal helper names like _rasterize_if_necessary,
log messages now show the user-facing origin (render_shapes, render_points,
render_images, render_labels).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: timtreis

src/spatialdata_plot/_logging.py

@@ -4,11 +4,27 @@
 import re
 from collections.abc import Iterator
 from contextlib import contextmanager
+from contextvars import ContextVar
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:  # pragma: no cover
     from _pytest.logging import LogCaptureFixture
 
+# Holds the public-facing function name (e.g. "render_shapes") for log messages.
+# Set at the top of each _render_* entry point so that all downstream helpers
+# report the user-visible origin rather than internal function names.
+_log_context: ContextVar[str] = ContextVar("_log_context", default="")
+
+
+class _ContextFilter(logging.Filter):
+    """Inject the public function name from ``_log_context`` into log records."""
+
+    def filter(self, record: logging.LogRecord) -> bool:
+        ctx = _log_context.get()
+        if ctx:
+            record.funcName = ctx
+        return True
+
 
 def _setup_logger() -> "logging.Logger":
     from rich.console import Console
@@ -21,6 +37,7 @@ def _setup_logger() -> "logging.Logger":
         console.is_jupyter = False
     ch = RichHandler(show_path=False, console=console, show_time=False)
     ch.setFormatter(logging.Formatter("%(funcName)s: %(message)s"))
+    ch.addFilter(_ContextFilter())
     logger.addHandler(ch)
 
     # this prevents double outputs

src/spatialdata_plot/pl/render.py

@@ -23,7 +23,7 @@
 from spatialdata.transformations.transformations import Identity
 from xarray import DataTree
 
-from spatialdata_plot._logging import logger
+from spatialdata_plot._logging import _log_context, logger
 from spatialdata_plot.pl.render_params import (
     Color,
     ColorbarSpec,
@@ -121,6 +121,7 @@ def _render_shapes(
     legend_params: LegendParams,
     colorbar_requests: list[ColorbarSpec] | None = None,
 ) -> None:
+    _log_context.set("render_shapes")
     element = render_params.element
     col_for_color = render_params.col_for_color
     groups = render_params.groups
@@ -608,6 +609,7 @@ def _render_points(
     legend_params: LegendParams,
     colorbar_requests: list[ColorbarSpec] | None = None,
 ) -> None:
+    _log_context.set("render_points")
     element = render_params.element
     col_for_color = render_params.col_for_color
     table_name = render_params.table_name
@@ -998,6 +1000,7 @@ def _render_images(
     rasterize: bool,
     colorbar_requests: list[ColorbarSpec] | None = None,
 ) -> None:
+    _log_context.set("render_images")
     sdata_filt = sdata.filter_by_coordinate_system(
         coordinate_system=coordinate_system,
         filter_tables=False,
@@ -1254,6 +1257,7 @@ def _render_labels(
     rasterize: bool,
     colorbar_requests: list[ColorbarSpec] | None = None,
 ) -> None:
+    _log_context.set("render_labels")
     element = render_params.element
     table_name = render_params.table_name
     table_layer = render_params.table_layer