支持后端解析参数表达式并保留工程JSON

app/main.py

@@ -22,6 +22,11 @@ from fastapi import FastAPI, HTTPException, Request, Response
 from fastapi.responses import FileResponse, HTMLResponse, StreamingResponse
 from pydantic import BaseModel, ConfigDict, Field, ValidationError
 
+from app.parameter_expression import (
+    ParameterExpressionError,
+    evaluate_parameter_expression,
+    expression_value_to_base_unit,
+)
 from app.simulation.performance import performance_span, profile_phase, profile_run
 from app.simulation.property_cache import property_cache_run
 from app.simulation.solvers.solver import SolverActivityTracker
@@ -1100,7 +1105,14 @@ def validate_reactflow_component_contract(
 
     parameter_values: dict[str, float] = {}
     for parameter in component_spec.parameters:
-        value = parameter_float(node, parameter.name, parameter.default)
+        value = parameter_float(
+            node,
+            parameter.name,
+            parameter.default,
+            quantity=parameter.quantity,
+            base_unit=parameter.unit,
+            expressions_allowed=parameter.editor is None,
+        )
         validation_message = parameter.validation_message(value)
         if validation_message is not None:
             raise ValueError(
@@ -1667,14 +1679,45 @@ def parameter_float(
     node: ReactFlowNodePayload | None,
     name: str,
     default: float,
+    *,
+    quantity: str = "dimensionless",
+    base_unit: str = "",
+    expressions_allowed: bool = True,
 ) -> float:
     if node is None:
         return default
     value = node.data.parameters.get(name, default)
     try:
-        return float(value)
+        numeric_value = float(value)
     except (TypeError, ValueError):
-        raise ValueError(f"Parameter '{name}' on component '{node.id}' must be numeric.")
+        if not isinstance(value, str):
+            raise ValueError(
+                f"Parameter '{name}' on component '{node.id}' must be numeric."
+            )
+        if not expressions_allowed:
+            raise ValueError(
+                f"PARAMETER_EXPRESSION_FORBIDDEN: Parameter '{name}' on component "
+                f"'{node.id}' is a discrete selection and cannot use an expression."
+            )
+        try:
+            evaluated = evaluate_parameter_expression(value)
+            selected_unit = node.data.parameterUnits.get(name, base_unit)
+            return expression_value_to_base_unit(
+                evaluated,
+                quantity=quantity,
+                selected_unit=selected_unit,
+            )
+        except ParameterExpressionError as exc:
+            raise ValueError(
+                f"PARAMETER_EXPRESSION_INVALID: Parameter '{name}' on component "
+                f"'{node.id}' contains an invalid expression: {exc}."
+            ) from exc
+    if not isfinite(numeric_value):
+        raise ValueError(
+            f"Parameter '{name}' on component '{node.id}' must be a finite "
+            "numeric value."
+        )
+    return numeric_value
 
 
 def pipe_config_from_node(node: ReactFlowNodePayload | None, pipe_config_type):