Note from Randy: the original JSON encoding specified what you suggested. It was change because of the need to ‘translate indexes’ when serialized values have their namespace table changed meant that every NodeId/QN string needed to be parsed. It was felt that simply substituting a numeric value for the NamespaceIndex was less work for generic JSON processors.

That said, I am working on a JSON NodeSet syntax that will introduce a more optimized NodeId/QN encoding.

add sample for problem to solve:

OpcEvents": [
{
"Id": "nsu=http://OPCFoundation.org/Interfaces/;s=179",
"DisplayName": "SimpleEvents",
"SelectClauses": [
{ "TypeDefinitionId": "i=2782", "AttributeId": 1 },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "EventId" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "ConditionName" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "SourceName" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "Message" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "Retain" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "ActiveState" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "Severity" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "Time" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "http://OPCFoundation.org/Interfaces/#AlarmIdentifier" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "http://OPCFoundation.org/Interfaces/#AuxParameters" ] },
{ "TypeDefinitionId": "i=2041", "BrowsePath": [ "EventType" ] }
],
"WhereClause": {
"Elements": [
{
"FilterOperator": "OfType",
"FilterOperands": [ { "Value": "nsu=http://OPCFoundation.org/Interfaces/;i=1006" } ]
}
]
}
}

image.png (142,744 bytes)   

image.png (142,744 bytes)   

It was agreed that there is demand for a string format, but not only to cover this case but also look at it from the viewpoint of Nodeset JSON.

The idea is to mandate the existing JSON encoding for point to point communication but allow for the string representation when JSON is persisted or when JSON is sent in non reversible form.

Randy will write up a proposal for a string format that can be universally used.

Defined a normative string representation for NodeId, ExpandedNodeId and QualifiedName in 5.1.10.

Reviewed by Martin. Solution addresses the need.

Agreed to changes in Web meeting.