How can I determine what fields are available to use with dot notations for field values?

Question

Using the queryrecord() function I can pass in a text array of field names that I want from the record type via query selection. At runtime I want this list of fields to be dynamically generated based on conditions. But when I have loaded the queryrecord into a local variable in the dashboard expression how can I determine what fields are available to use with dot notations for field values?... 
 OriginalPostID-91574 
 OriginalPostID-91574

Jorge Sanchez · Accepted Answer

I believe you can use the index() function but instead of index, use the name of the field you want and a default "N/A". Then you can wrap that around an if and check if the value is different from "N/A" to see if it was set.

sikhivahans · Answer

Hi tim.clarke, index() will be useful in your case. Use fn!index(local!yourVariable.data,<columnName>,{}). If the field Name exists you will get a non-null data which means that you can access the field with dot notation. Else if you already have the field names stored in a local variable, you can directly access the data something like local!yourVariable.data["columnName"]