Centralise dynamic NeXus transforms for f144-driven geometry

src/ess/livedata/config/instrument.py

@@ -3,12 +3,16 @@
 from __future__ import annotations
 
 from collections import UserDict
-from collections.abc import Callable, Sequence
+from collections.abc import Callable, Mapping, Sequence
 from dataclasses import dataclass, field
 from typing import TYPE_CHECKING, Any
 
 if TYPE_CHECKING:
+    import sciline
+
     from ess.livedata.handlers.detector_view_specs import SpectrumViewSpec
+    from ess.livedata.handlers.log_context import LogContextBinding
+    from ess.livedata.handlers.stream_processor_workflow import ValueLog
 
 import pydantic
 import scipp as sc
@@ -90,6 +94,7 @@ class Instrument:
     monitors: list[str] = field(default_factory=list)
     workflow_factory: WorkflowFactory = field(default_factory=WorkflowFactory)
     f144_attribute_registry: dict[str, dict[str, Any]] = field(default_factory=dict)
+    log_context_bindings: list[LogContextBinding] = field(default_factory=list)
     source_metadata: dict[str, SourceMetadata] = field(default_factory=dict)
     _detector_numbers: dict[str, sc.Variable] = field(default_factory=dict)
     _nexus_file: str | None = None
@@ -107,6 +112,15 @@ def __post_init__(self) -> None:
             register_timeseries_workflow_specs,
         )
 
+        # Auto-derive f144_attribute_registry entries from bindings that
+        # declare units. Explicit registry entries win on conflict.
+        for binding in self.log_context_bindings:
+            if binding.units is None:
+                continue
+            self.f144_attribute_registry.setdefault(
+                binding.stream_name, {'units': binding.units}
+            )
+
         timeseries_names = list(self.f144_attribute_registry.keys())
         self._timeseries_workflow_handle = register_timeseries_workflow_specs(
             instrument=self, source_names=timeseries_names
@@ -350,6 +364,64 @@ def add_logical_view(
         )
         return handle
 
+    def apply_dynamic_transforms(
+        self,
+        workflow: sciline.Pipeline,
+        components: Mapping[str, type],
+    ) -> dict[str, type[ValueLog]]:
+        """Patch ``workflow`` to drive matching NXlog placeholders from f144 streams.
+
+        For each ``(source_name, component_type)`` entry, selects every
+        :class:`DynamicTransformBinding` in :attr:`log_context_bindings`
+        whose ``dependent_sources`` set includes that source name. For each
+        component type with at least one match, replaces the
+        ``NeXusTransformationChain[T, SampleRun]`` provider with a closure
+        that consumes the matched bindings' ``log_key`` parameters and
+        writes the latest sample into the chain. Non-transform bindings
+        on the instrument are ignored.
+
+        Parameters
+        ----------
+        workflow:
+            The Sciline pipeline to patch in place.
+        components:
+            Mapping ``source_name -> component_type`` for the
+            essreduce-loaded NeXus components whose ``depends_on`` chain
+            might need patching (e.g. ``{'loki_detector_0': NXdetector,
+            aux_source_names['incident_monitor']: Incident, ...}``).
+            Callers own the alias resolution: source names are the
+            actual on-disk names, not aliases.
+
+        Returns
+        -------
+        :
+            Mapping ``stream_name -> log_key`` for every binding that
+            actually matched; pass to :class:`StreamProcessorWorkflow`
+            as ``context_keys`` so SPW's wrapping rule delivers each
+            f144 NXlog to the right Sciline parameter.
+        """
+        from ess.livedata.handlers.dynamic_transforms import (
+            DynamicTransformBinding,
+            build_patched_chain_provider,
+        )
+
+        transform_bindings = [
+            b
+            for b in self.log_context_bindings
+            if isinstance(b, DynamicTransformBinding)
+        ]
+        context_keys: dict[str, type[ValueLog]] = {}
+        for source_name, component_type in components.items():
+            matched = [
+                b for b in transform_bindings if source_name in b.dependent_sources
+            ]
+            if not matched:
+                continue
+            workflow.insert(build_patched_chain_provider(component_type, matched))
+            for binding in matched:
+                context_keys[binding.stream_name] = binding.log_key
+        return context_keys
+
     def register_spec(
         self,
         *,
@@ -410,6 +482,14 @@ def register_spec(
         -------
         Handle for attaching factory later.
         """
+        # Merge log-context aux sources scoped per spec source list, so
+        # factories whose bindings cover any of the spec's sources
+        # automatically have the routing layer deliver matching f144 streams.
+        if self.log_context_bindings and source_names:
+            from ess.livedata.handlers.log_context import compose_aux_sources
+
+            aux_sources = compose_aux_sources(self, list(source_names), aux_sources)
+
         spec = WorkflowSpec(
             instrument=self.name,
             group=group,
@@ -450,10 +530,7 @@ def load_factories(self) -> None:
             )
 
         if self._logical_views:
-            from ess.livedata.handlers.detector_view import (
-                DetectorViewFactory,
-                InstrumentDetectorSource,
-            )
+            from ess.livedata.handlers.detector_view import DetectorViewFactory
             from ess.livedata.handlers.detector_view import (
                 LogicalViewConfig as ScilineLogicalViewConfig,
             )
@@ -467,8 +544,8 @@ def load_factories(self) -> None:
                     spectrum_view=config.spectrum_view,
                 )
                 factory = DetectorViewFactory(
-                    data_source=InstrumentDetectorSource(self),
                     view_config=view_config,
+                    instrument=self,
                 )
                 handle.attach_factory()(factory.make_workflow)
 

src/ess/livedata/config/instruments/bifrost/factories.py

@@ -80,6 +80,7 @@ def _monitor_workflow_factory(source_name: str, params: TOAOnlyMonitorDataParams
             edges=params.get_active_edges(),
             range_filter=params.get_active_range(),
             coordinate_mode='toa',
+            instrument=instrument,
         )
 
     # Create base reduction workflow

src/ess/livedata/config/instruments/dream/factories.py

@@ -92,6 +92,7 @@ def _resolve_lookup_table_filename(instrument_configuration):
                 flip_x=True,
             ),
         },
+        instrument=instrument,
     )
 
     @specs.projection_handle.attach_factory()
@@ -133,6 +134,7 @@ def _monitor_workflow_factory(source_name: str, params: DreamMonitorDataParams):
             coordinate_mode=mode,
             lookup_table_filename=lookup_table_filename,
             geometry_filename=geometry_filename,
+            instrument=instrument,
         )
 
     # Powder reduction workflow setup

src/ess/livedata/config/instruments/dummy/factories.py

@@ -29,7 +29,6 @@ def setup_factories(instrument: Instrument) -> None:
     from ess.livedata.handlers.area_detector_view import AreaDetectorView
     from ess.livedata.handlers.detector_view import (
         DetectorViewFactory,
-        InstrumentDetectorSource,
         LogicalViewConfig,
     )
     from ess.livedata.handlers.stream_processor_workflow import StreamProcessorWorkflow
@@ -44,8 +43,8 @@ def setup_factories(instrument: Instrument) -> None:
 
     # Create detector view for event-mode panel_0 using Sciline-based factory
     _panel_0_view = DetectorViewFactory(
-        data_source=InstrumentDetectorSource(instrument),
         view_config=LogicalViewConfig(),  # Identity transform
+        instrument=instrument,
     )
 
     specs.panel_0_view_handle.attach_factory()(_panel_0_view.make_workflow)
@@ -78,6 +77,7 @@ def _monitor_workflow_factory(source_name: str, params: TOAOnlyMonitorDataParams
             edges=params.get_active_edges(),
             range_filter=params.get_active_range(),
             coordinate_mode='toa',
+            instrument=instrument,
         )
 
     # Total counts workflow

src/ess/livedata/config/instruments/estia/factories.py

@@ -54,6 +54,7 @@ def _monitor_workflow_factory(source_name: str, params: TOAOnlyMonitorDataParams
             edges=params.get_active_edges(),
             range_filter=params.get_active_range(),
             coordinate_mode='toa',
+            instrument=instrument,
         )
 
     @specs.reflectometry_reduction_handle.attach_factory()

src/ess/livedata/config/instruments/loki/factories.py

@@ -51,8 +51,6 @@ def setup_factories(instrument: Instrument) -> None:
         StreamProcessorWorkflow,
     )
 
-    from .specs import LOKI_DYNAMIC_TRANSFORMS
-
     _nexus_geometry_filename = get_nexus_geometry_filename('loki')
 
     def _resolve_lookup_table_filename() -> str:
@@ -102,11 +100,11 @@ def _make_base_workflow() -> LokiWorkflow:
             )
             for name, res in _bank_resolutions.items()
         },
-        # Drive the rear bank's NeXus 'detector_carriage' transformation
-        # from the live f144 carriage readback. The mapping is shared with
-        # loki/specs.py so the spec routes the stream only to the consuming
-        # source.
-        dynamic_transforms=LOKI_DYNAMIC_TRANSFORMS,
+        # Apply the instrument's dynamic-transform registry so the rear
+        # bank's carriage NXlog placeholder is driven by the live f144
+        # readback. Other banks have no matching binding, so the helper is
+        # a no-op for them.
+        instrument=instrument,
     )
 
     from ess.livedata.handlers.detector_view_specs import DetectorViewParams
@@ -157,6 +155,7 @@ def _monitor_workflow_factory(source_name: str, params: MonitorDataParams):
             coordinate_mode=mode,
             lookup_table_filename=lookup_table_filename,
             geometry_filename=geometry_filename,
+            instrument=instrument,
         )
 
     # --- Providers for current_run transmission mode ---
@@ -209,6 +208,18 @@ def _i_of_q_factory(
         wf[sans_types.WavelengthBins] = params.wavelength_edges.get_edges()
         wf[BeamCenter] = params.beam_center.get_vector()
 
+        # Patch the workflow to drive any matching NXlog placeholder along
+        # the loaded components' depends_on chains from f144 streams.
+        # For LOKI today this covers the rear-bank carriage (issue #922).
+        context_keys = instrument.apply_dynamic_transforms(
+            wf,
+            {
+                source_name: NXdetector,
+                aux_source_names['incident_monitor']: Incident,
+                aux_source_names['transmission_monitor']: Transmission,
+            },
+        )
+
         target_keys: dict[str, sciline.typing.Key] = {
             'i_of_q': IntensityQ[SampleRun],
         }
@@ -235,6 +246,7 @@ def _i_of_q_factory(
         return StreamProcessorWorkflow(
             wf,
             dynamic_keys=_dynamic_keys(source_name),
+            context_keys=context_keys,
             target_keys=target_keys,
             accumulators=_accumulators,
         )

src/ess/livedata/config/instruments/loki/specs.py

@@ -17,32 +17,40 @@
     AuxSources,
     WorkflowOutputsBase,
 )
-from ess.livedata.handlers.detector_view.types import TransformValueStream
-from ess.livedata.handlers.detector_view_specs import (
-    DetectorROIAuxSources,
-    register_detector_view_spec,
-)
+from ess.livedata.handlers.detector_view_specs import register_detector_view_spec
+from ess.livedata.handlers.dynamic_transforms import DynamicTransformBinding
 from ess.livedata.handlers.monitor_workflow_specs import (
     MonitorDataParams,
     register_monitor_workflow_specs,
 )
+from ess.livedata.handlers.stream_processor_workflow import ValueLog
 from ess.livedata.handlers.wavelength_lut_workflow_specs import (
     register_wavelength_lut_workflow_spec,
 )
 
 from .views import get_tube_view
 
-#: Per-source bindings of NeXus transformation entries to live f144 streams.
-#: Single source of truth shared between the spec (for routing via
-#: ``DetectorROIAuxSources``) and the factory (for graph wiring via
-#: ``DetectorViewFactory(dynamic_transforms=...)``). Only the rear bank has
-#: a live carriage readback; other banks have no dynamic geometry.
-LOKI_DYNAMIC_TRANSFORMS: dict[str, TransformValueStream] = {
-    'loki_detector_0': TransformValueStream(
-        transform_name='/entry/instrument/detector_carriage/value',
-        aux_stream='detector_carriage',
+
+#: Sciline key for the rear-detector carriage f144 NXlog. Subclassing
+#: ValueLog gives the binding its own grep-able Sciline node, distinct
+#: from any future bindings on the same component type.
+class DetectorCarriageLog(ValueLog):
+    """Carriage f144 NXlog (drives ``loki_detector_0`` chain)."""
+
+
+#: Dynamic-transform bindings for LOKI. Only the rear bank's carriage entry
+#: is dynamic; other banks have no live position readback. ``beam_monitor_m4``
+#: is also movable (on the carriage, probably), but we currently have no file
+#: with a correct depends_on chain.
+LOKI_DYNAMIC_TRANSFORMS = [
+    DynamicTransformBinding(
+        nxlog_path='/entry/instrument/detector_carriage/value',
+        stream_name='detector_carriage',
+        log_key=DetectorCarriageLog,
+        dependent_sources=frozenset({'loki_detector_0'}),
+        units='mm',
     ),
-}
+]
 
 
 class TransmissionMode(StrEnum):
@@ -209,6 +217,7 @@ class SansWorkflowParams(pydantic.BaseModel):
     f144_attribute_registry={
         name: {'units': info['units']} for name, info in f144_log_streams.items()
     },
+    log_context_bindings=LOKI_DYNAMIC_TRANSFORMS,
     source_metadata={
         'loki_detector_0': SourceMetadata(title='Rear'),
         'loki_detector_1': SourceMetadata(title='Mid Top'),
@@ -275,7 +284,6 @@ class SansWorkflowParams(pydantic.BaseModel):
     instrument=instrument,
     projection='xy_plane',
     source_names=detector_names,
-    aux_sources=DetectorROIAuxSources(dynamic_transforms=LOKI_DYNAMIC_TRANSFORMS),
 )
 
 # Register tube view for all detector banks

src/ess/livedata/config/instruments/nmx/factories.py

@@ -16,7 +16,6 @@ def setup_factories(instrument: Instrument) -> None:
     # Lazy imports
     from ess.livedata.handlers.detector_view import (
         DetectorViewFactory,
-        InstrumentDetectorSource,
         LogicalViewConfig,
     )
 
@@ -37,8 +36,8 @@ def setup_factories(instrument: Instrument) -> None:
 
     # Create detector view using Sciline-based factory (identity transform)
     _nmx_panels_view = DetectorViewFactory(
-        data_source=InstrumentDetectorSource(instrument),
         view_config=LogicalViewConfig(),  # Identity transform
+        instrument=instrument,
     )
 
     specs.panel_xy_view_handle.attach_factory()(_nmx_panels_view.make_workflow)
@@ -55,4 +54,5 @@ def _monitor_workflow_factory(source_name: str, params: TOAOnlyMonitorDataParams
             edges=params.get_active_edges(),
             range_filter=params.get_active_range(),
             coordinate_mode='toa',
+            instrument=instrument,
         )

src/ess/livedata/config/instruments/odin/factories.py

@@ -28,4 +28,5 @@ def _monitor_workflow_factory(source_name: str, params: TOAOnlyMonitorDataParams
             edges=params.get_active_edges(),
             range_filter=params.get_active_range(),
             coordinate_mode='toa',
+            instrument=instrument,
         )

src/ess/livedata/config/instruments/tbl/factories.py

@@ -29,4 +29,5 @@ def _monitor_workflow_factory(source_name: str, params: TOAOnlyMonitorDataParams
             edges=params.get_active_edges(),
             range_filter=params.get_active_range(),
             coordinate_mode='toa',
+            instrument=instrument,
         )