WoT / NodeSet conversion

Opc.Ua.Wot.WotNodeSetConverter converts OPC UA NodeSet2 documents to WoT Thing Models / Thing Descriptions and materializes WoT documents back to NodeSet2. The converter preserves a byte-exact uav:nodeSet envelope when requested, uses the structured uav:nodes projection when the readable vocabulary is not complete, and otherwise synthesizes NodeSet2 from the readable WoT terms.

WoT to NodeSet defaults

The table below lists the defaults the current WoT-to-NodeSet materializer applies when the WoT input lacks information needed for a NodeSet2 projection. Rows marked Fails emit an error diagnostic and ToNodeSet throws. Rows marked Default substitute the listed value; warnings or informational diagnostics are noted where the code emits them.

Missing WoT input	Behaviour	Materialized value
Convertible content: no uav:nodeSet, no uav:nodes, and neither a Thing Model nor a Thing Description kind	Fails	NoConvertibleContent error; no NodeSet is returned.
Model namespace: root uav:id has no nsu=<NamespaceUri>;... part and document id is absent	Default	NamespaceUris = ["urn:opcua:wot:synthesized"] and Models[0].ModelUri = "urn:opcua:wot:synthesized". This is intentionally synthetic and should be replaced by an authored namespace in portable documents.
Root local name: root uav:browseName is absent	Default	Sanitized title (letters, digits, _, -) when non-empty; otherwise Thing.
Root uav:id	Default	Deterministic NodeId ns=1;s=<rootLocal> and an informational GeneratedNodeId diagnostic.
Root uav:browseName	Default	1:<rootLocal>.
Root title	Default	Root DisplayName becomes <rootLocal>.
Thing Model root event annotation uav:eventType	Default	Root is a non-abstract UAObjectType with inverse HasSubtype to BaseObjectType (i=58). If the event annotation is present, the default supertype is BaseEventType (i=2041).
Thing Description root type information	Default	Root is a UAObject with HasTypeDefinition to BaseObjectType (i=58).
Root description	Default	No Description field is materialized.
Property affordance uav:browseName	Default	The affordance map key is used as the local name and BrowseName 1:<key>.
Property affordance uav:id	Default	Deterministic NodeId ns=1;s=<rootLocal>/<propertyLocal>.
Property DataSchema type or an unrecognized type	Default	OPC UA BaseDataType (i=24). type: object maps to BaseObjectType (i=22) and emits an unsupported-schema warning; type: array currently falls back to BaseDataType with the same warning, which is a deliberately conservative but coarse default.
Property readOnly and writeOnly	Default	Missing flags mean read/write access (`CurrentRead
Property title	Default	No DisplayName field is materialized for the variable.
Property description	Default	No Description field is materialized for the variable.
Property type definition	Default	HasTypeDefinition to BaseDataVariableType (i=63).
Action affordance uav:browseName	Default	The affordance map key is used as the local name and BrowseName 1:<key>.
Action affordance uav:id	Default	Deterministic NodeId ns=1;s=<rootLocal>/<actionLocal>.
Action title	Default	No DisplayName field is materialized for the method.
Event affordance uav:browseName	Default	The affordance map key is used as the local name and BrowseName 1:<key>.
Event affordance uav:id	Default	Deterministic NodeId ns=1;s=<rootLocal>/<eventLocal>.
Event title	Default	No DisplayName field is materialized for the event type.
Event type abstraction/supertype	Default	Event affordances materialize as non-abstract UAObjectType nodes with inverse HasSubtype to BaseEventType (i=2041) and a root GeneratesEvent reference.
uav:modellingRule on a property or action	Default	No HasModellingRule reference is materialized.
uav:hasComponent / uav:componentOf entry has no matching typed ReferenceType link	Default	HasComponent is used for the component reference.
Binding link has no resolvable model-name relation and no uav:refId	Default	uav:componentModel maps to HasComponent; other generic binding relations map to Organizes.
Reference link points to another Thing by URI and no resolver is supplied or the resolver cannot find uav:id	Default	The reference is omitted and a warning diagnostic is emitted; no placeholder NodeId is generated.
Invalid namespace-qualified uav:id / uav:browseName syntax or unbound compact-name prefix	Fails	An error diagnostic is emitted; ToNodeSet throws even though synthesis continues far enough to collect diagnostics.
Event affordance says @type: uav:eventType and uav:isEvent: false	Fails	EventAnnotationConflict error; the two terms must not contradict each other.