feat(abcip): thread nested-struct template id so nested UDT members are addressable (#6)

2026-06-18 11:33:41 -04:00
parent 56c136b0fd
commit 3d8ce4e85f
5 changed files with 122 additions and 13 deletions
@@ -88,12 +88,18 @@ public static class CipTemplateObjectDecoder
                ? AbCipDataType.Structure
                : (CipSymbolObjectDecoder.MapTypeCode(typeCode) ?? AbCipDataType.Structure);

+            // For a struct member the low 12 bits are the nested UDT's template instance id (same encoding as the
+            // Symbol Object), NOT a primitive type code — capture it so the nested shape can be fetched. Use the
+            // FULL 12-bit mask (not the byte-cast typeCode, which truncates a 12-bit id).
+            var nestedTemplateId = isStruct ? (uint?)(info & MemberInfoTypeCodeMask) : null;
+
            var memberName = i < memberNames.Length ? memberNames[i] : $"<member_{i}>";
            members.Add(new AbCipUdtMember(
                Name: memberName,
                Offset: offset,
                DataType: dataType,
-                ArrayLength: arraySize == 0 ? 1 : arraySize));
+                ArrayLength: arraySize == 0 ? 1 : arraySize,
+                NestedTemplateId: nestedTemplateId));
        }

        return new AbCipUdtShape(