question Re: Return a scalar value with EvaluateJSONPath processor in Support Questions

Return a scalar value with EvaluateJSONPath processor

ChuckE — Thu, 13 Oct 2022 01:17:07 GMT

I need to use wildcard syntax in a JSON path to return the color of the bike as a scalar value. However, the problem is that when I use wildcard syntax with the EvaluateJSONPath processor it always returns an array. For example

This path returns a scalar value: $.store.bicycle.color ==> red

This path returns an array: $..bicycle.color ==> ['red']

Is it possible to use the EvaluateJSONPath processor with wildcards and get a scalar value in return?

Or, is it possible to extract the value from the array without using an additional processor?

{ "store": { "bicycle": { "color": "red", "price": 19.95 } }, "expensive": 10 }

Re: Return a scalar value with EvaluateJSONPath processor

SAMSAL — Thu, 13 Oct 2022 13:11:58 GMT

Hi,

I dont think there is a way to do that in one processor, check out this post around the problem with possible solution:

https://community.cloudera.com/t5/Support-Questions/Unable-to-return-a-scalar-value-for-the-expression-from-NIFI/td-p/213677

If you find this helpful please accept solution.

Re: Return a scalar value with EvaluateJSONPath processor

ChuckE — Thu, 13 Oct 2022 15:52:13 GMT

Thanks @SAMSAL, I was tracking that previous post but since it was so old I was hoping newer versions of NiFi could address this. This is such a simple thing with XML and the EvaluateXPath processor, I am just surprised that we can't do something similar with JSON. Oh well, 2 processors it is.