refactor(commons): consolidate List element-type/coercion into AttributeValueCodec; InstanceActor + CLI reuse it (#93)

2026-06-19 02:03:09 -04:00
parent 2935c41bf7
commit 47f5ca687c
4 changed files with 120 additions and 57 deletions
@@ -64,7 +64,13 @@ public static class AttributeValueCodec
        _ => el.GetRawText()                       // number/bool → "10" / "1.5" / "true"
    };

-    private static Type ElementClrType(DataType t) => t switch
+    /// <summary>
+    /// The CLR element type backing a <see cref="DataType.List"/> of the given
+    /// element scalar — the single source of truth for the List element CLR
+    /// mapping. Throws <see cref="FormatException"/> for an unsupported element
+    /// type (see <see cref="IsValidElementType"/>).
+    /// </summary>
+    public static Type ElementClrType(DataType t) => t switch
    {
        DataType.String => typeof(string),
        DataType.Int32 => typeof(int),
@@ -75,6 +81,49 @@ public static class AttributeValueCodec
        _ => throw new FormatException($"Unsupported list element type '{t}'.")
    };

+    /// <summary>
+    /// Coerces a live CLR enumerable (e.g. an OPC UA array) into a typed
+    /// <c>List&lt;<see cref="ElementClrType"/>&gt;</c> for the given element type,
+    /// converting each element with invariant culture (round-trip parse for
+    /// DateTime). Strings are parsed; other CLR types are converted via
+    /// <see cref="Convert"/>. This is the object-input counterpart to the
+    /// string-input parsing in <see cref="Decode"/>: callers holding decoded JSON
+    /// strings go through <see cref="Decode"/>; callers holding a runtime
+    /// collection use this. Throws <see cref="FormatException"/> for an
+    /// unsupported element type and may throw on an element that cannot be
+    /// converted (the caller decides how to handle the failure).
+    /// </summary>
+    public static IList CoerceEnumerable(IEnumerable source, DataType elementType)
+    {
+        ArgumentNullException.ThrowIfNull(source);
+        var clrType = ElementClrType(elementType);
+        var list = (IList)Activator.CreateInstance(typeof(List<>).MakeGenericType(clrType))!;
+        foreach (var element in source)
+            list.Add(CoerceElement(element, elementType));
+        return list;
+    }
+
+    private static object CoerceElement(object? element, DataType t)
+    {
+        if (element is null)
+            throw new FormatException("List elements may not be null.");
+
+        var c = CultureInfo.InvariantCulture;
+        return t switch
+        {
+            DataType.String => Convert.ToString(element, c)
+                ?? throw new FormatException("Null string element."),
+            DataType.Int32 => element is string si ? int.Parse(si, c) : Convert.ToInt32(element, c),
+            DataType.Float => element is string sf ? float.Parse(sf, c) : Convert.ToSingle(element, c),
+            DataType.Double => element is string sd ? double.Parse(sd, c) : Convert.ToDouble(element, c),
+            DataType.Boolean => element is string sb ? bool.Parse(sb) : Convert.ToBoolean(element, c),
+            DataType.DateTime => element is string sdt
+                ? DateTime.Parse(sdt, c, DateTimeStyles.RoundtripKind)
+                : Convert.ToDateTime(element, c),
+            _ => throw new FormatException($"Unsupported list element type '{t}'.")
+        };
+    }
+
    private static object? ParseScalar(string? s, DataType t)
    {
        if (s is null) throw new FormatException("List elements may not be null.");