Re: Empty IA5String

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 09:28 AM 11/9/2004, Hallvard B Furuseth wrote:
>John McMeeking writes:
>> On a personal note, I've always found the notion of an zero-length
>> value hard to digest.  I could really use a real world example (not in
>> the drafts, just to help me accept the concept) where a zero-length
>> value has a different meaning than no value.
>
>I can give you what might have become a real-world example at our site
>if Directory Strings could be zero-length:  A 'vacation message'
>attribute which the mail system would check.  If the attribute was
>present, the mail system would send a vacation message in response to
>incoming messages, with a standard initial text + the optional
>user-supplied message.

Use an " " to indicate no user-supplied message...

>As it is, we ended up another boolean attribute which means 'there is an
>active vacation message', and only use the vacation attribute if the
>boolean is TRUE.
>
>Except for that, I have no problem with empty attributes in general.
>The presence of a value - or of an attribute - is information.  Its
>contents is some other information, and its format depends on the
>application.  Empty strings are rare, but not useless.  Think of an
>empty DN, for example.  (Yes, I know that does not have string syntax.)
>
>-- 
>Hallvard