Most form elements offer an additional category: Value trasnformation. Here you specify a Calculation expression. A calculation expression is a configurable formula. It manipulates how element data is read and written.
By default, an element reads and writes its data directly through its data field. To provide an adapter layer, two calculation expressions are available.
To internal value
This expression converts the value read from the data. The example uses a date field.
A profile reads the date from a data set in the format yyyy/dd/MM. The calculation expression acts as an adapter. It converts this format into a valid date: $parseDate($input,yyyy/dd/MM).
To external value
This expression converts the value to be written to the data. The example uses a date field.
The date is passed to a profile as a string in the format yyyy/dd/MM. The calculation expression acts as an adapter. It converts the date value into a string: $fd($input,yyyy/dd/MM).
NOTE
Elements that perform a value transformation are marked with a dedicated icon:
