UI Expression Error: Invalid Equals Comparison with Null Date Value

Question

I’ve set up a date search in my Appian interface backed by a Cloud DB table. When users select a date, it updates a rule input, which is then used to filter records. The filtering works well and shows only the data for that selected date.

query: a!query(
                    filter: if(
                      isnull(ri!onInputChange),
                      null,
                      a!queryFilter(
                        field: "createdOnDate",
                        operator: "=",
                        value: ri!onInputChange
                      )
                    )

But, when I am adding the interface as a page to the Site, I am getting the error below:
Error Evaluating UI Expression Expression evaluation error [evaluation ID = 296a3:3b232] in rule <table_Name> : Cannot apply operator [EQUALS] to field [createdOnDate] when comparing to value [TypedValue[it=49,v=<null>]].

Shubham Aware · Answer

When the interface is added as a page to the Site, the value being passed in the filter (ri!onInputChange) appears as null or an invalid typed value for the equals operator on the date field. Try below 2 approach to handle null. a!queryFilter(
 field: "createdOnDate",
 operator: "=",
 value: ri!onInputChange,
 applyWhen: a!isNotNullOrEmpty(ri!onInputChange)
) Or filter: if(
 or(
 isNullOrEmpty(ri!onInputChange),
 ri!onInputChange = ""
 ),
 {}, /* Return empty filter array instead of null */
 a!queryFilter(
 field: "createdOnDate",
 operator: "=",
 value: ri!onInputChange
 )
)