refactor nodes into standalone file

backend/nodes/value_display.py

@@ -0,0 +1,43 @@
+from __future__ import annotations
+from backend.node_registry import register_node
+from backend.data_types import MeasureTable
+from backend.nodes.helpers import _measurement_entry, _measurement_value, _scalar_payload
+
+
+@register_node(display_name="Value Display")
+class ValueDisplay:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "value": ("VALUE_SOURCE",),
+                "measurement": ("STRING", {
+                    "default": "",
+                    "choices_from_measure_input": "value",
+                    "show_when_source_type": {
+                        "value": ["MEASURE_TABLE"],
+                    },
+                }),
+            }
+        }
+
+    RETURN_TYPES = ("FLOAT",)
+    RETURN_NAMES = ("value",)
+    FUNCTION = "display_value"
+
+    DESCRIPTION = "Display a FLOAT, or a selected numeric row from a measurement table, and pass the value through unchanged."
+
+    _broadcast_value_fn = None
+    _current_node_id: str = ""
+
+    def display_value(self, value, measurement: str = "") -> tuple:
+        unit = ""
+        if isinstance(value, MeasureTable):
+            row = _measurement_entry(value, measurement)
+            numeric = _measurement_value(value, measurement)
+            unit = row.get("unit", "") if isinstance(row.get("unit"), str) else ""
+        else:
+            numeric = float(value)
+        if ValueDisplay._broadcast_value_fn is not None:
+            ValueDisplay._broadcast_value_fn(ValueDisplay._current_node_id, _scalar_payload(numeric, unit))
+        return (numeric,)