validateSpecific
Validates that values are unique across the rows of a repeatable control. Works on the global form state.
Algorithm:
Takes all rows of the control
Builds a uniqueness key for every row from the values of the given fields
Checks whether the key has already been seen
On a duplicate, sets an error with the row number
The check runs only when uniqueFields is not empty.
Parameters
controlContext
control name with the row context (needed to build hierarchical names)
value
the rows of the repeatable control