NLog JSON structred event-property - json

Question

This is my NLog configuration:
<layout type="JsonLayout">
<attribute name="businessProcessName" layout="${event-properties:rawMessage:item=BusinessProcess}" />
<attribute name="businessDepartmentName" layout="${event-properties:rawMessage:item=BusinessDepartment}" />
<attribute name="logType" layout="${event-properties:rawMessage:item=logType}" />
<attribute name="queueName" layout="${event-properties:rawMessage:item=QueueName}" />
<attribute name="data" layout="${event-properties:rawMessage:item=LogF_AllTransactionData}" />
</layout>
Which is giving me the following result:
{ "businessProcessName": "ACME", "businessDepartmentName": "Lior", "logType": "User", "queueName": "LoggingTest", "data": "{\r\n \"ExecuterJobGUID\": \"Studio_05fe3a0e-dc3b-4635-a521-5fe450cdb13e\",\r\n \"LogF_TransactionReference\": \"MyTransaction\",\r\n \"LogF_StartTransactionTime\": \"08\/02\/2022 17:11:33\",\r\n \"LogF_TransactionId\": \"23031\",\r\n \"LogF_QueueName\": \"LoggingTest\",\r\n \"LogF_QueueDefinitionId\": 545,\r\n \"LogF_SpecificContent\": {\r\n \"FirstName\": \"Lior\",\r\n \"LastName\": \"Hen\",\r\n \"BirthDate\": \"1989-12-03T00:00:00Z\"\r\n },\r\n \"LogF_Progress\": \"\",\r\n \"LogF_RetryNo\": 0,\r\n \"Gender\": \"Male\",\r\n \"City\": \"Ashdod\"\r\n}" }
I have two questions please:
How can I bring 'data' as Json and not as string?
How can I bring a single key from 'data', such as 'LogF_TransactionReference'?
Thank you!

Answer 1

If you know that the LogEvent-Property contains valid JSON, then you can specify encode="false":
<attribute name="data" layout="${event-properties:item=LogF_AllTransactionData}" encode="false" />
Then NLog will not encode/escape the LogEvent-Property-Value as JSON-string-property.
NLog ${event-properties} has the objectpath-option, but it requires that you provide the original object, instead of having serialized to JSON upfront.
<attribute name="data_id" layout="${event-properties:item=LogF_AllTransactionData:objectpath=Id}" />
<attribute name="data" layout="${event-properties:item=LogF_AllTransactionData:format=#}" encode="false" />
Alternative approach would be to implement custom-layout-renderer that parses the JSON-Object and output the wanted property. But it has a performance penalty.
See also: https://github.com/NLog/NLog/wiki/How-to-use-structured-logging