Enforcing a minimum character length on a form field in I4GL

Question

How can I add character length in a field on Informix 4GL. I have a description column, and I want to enforce a minimum length 10 characters in this field; if the entered string is less than 10 characters, send the user back to re-enter the data.

Answer 1

To enforce that constraint, you would need to use an AFTER FIELD clause, check the length of the entered data, and send the user back if it is not long enough:

AFTER FIELD mustbe10
    IF LENGTH(recname.mustbe10) < 10 THEN
        MESSAGE "You must enter at least 10 characters"
        NEXT FIELD mustbe10
    END IF

I'm assuming it is a field that does not allow nulls; if it does allow nulls, you need to allow for that in the testing.

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Incidentally, you can seriously expect to have to deal with descriptions like 'Aaaaaaaaaa' and 'asdfasdfasdf' if you put this requirement on users. They may also get more creative; you can fit a couple of 4-letter words and an exclamation mark into a 10-character limit.