Confiform Rest API to update a field value

[JJ Fang]

I am trying to use the Confiform Rest API (https://wiki.vertuna.com/spaces/CONFIFORMS/pages/70582777/ConfiForms+Server+REST+API+version+1) to update an existing field value. The actual URL I was using is:

PUT /rest/confiforms/1.0/updateFieldValue/<pageId>/<formName> -H "Content-Type: application/json" -d '{"fields":{"<fieldName":"value"}}'

I got the following response: 

{"result":"Backend exception. Caused by Cannot read the array length because \"fieldAndValues\" is null"}

It is possible that my HTTP PUT body data structure was not what was expected by the ConfiForm backend. Can you provide a sample URL and JSON structure? 

My Confiform version is 3.21.7, and Confluence version is 9.2.5 (DataCenter)

Thank you very much!

[Alex Medved _ConfiForms_ · Accepted solution]

It does not expect the body, but requires a "fv" parameter

/rest/confiforms/1.0/updateFieldValue/{pageId}/{formName}?query={filter}&fv=fieldvalue:value