The Enumeration Syntax Extension

The X-ENUM attribute syntax extension can be used to define new string syntaxes with values restricted to a set of defined, ordered values. The following example defines an X-ENUM attribute to the schema.

$ ldapmodify -p 1389 -h localhost -D "cn=Directory Manager" -w password
dn: cn=schema
changetype: modify
add: ldapsyntaxes
ldapSyntaxes: ( 1.3.6.1.4.1.32473.4 DESC 'Day Of The Week'
  X-ENUM ( 'monday' 'tuesday' 'wednesday' 'thursday'
  'friday' 'saturday' 'sunday' ) )

This new syntax can be used to define attributes and object classes, as shown in the following example.

$ ldapmodify -p 1389 -h localhost -D "cn=Directory Manager" -w password
dn: cn=schema
changetype: modify
add: attributetypes
attributetypes: ( 1.3.6.1.4.1.32473.5 NAME 'example-attr-enum' SYNTAX
1.3.6.1.4.1.32473.4 )
-
add: objectclasses
objectclasses: ( 1.3.6.1.4.1.32473.6 NAME 'exampleOCenum' SUP top AUXILIARY
MUST example-attr-enum)

Values for example-attr-enum attributes must match the defined pattern, or the server rejects them.

Enumerated values are not case-sensitive, so both of the following examples are accepted:

example-attr-enum: thursday
example-attr-enum: Thursday

Enumerated attribute values are literal (and not internationalized), so the following example does not match the pattern and is rejected, regardless of any semantic equivalence:

example-attr-enum: jeudi

The defined values specify an order, so enumerated attributes can be used in relative comparison filters, as shown in the following example:

(example-attr-enum>=wednesday)

The preceding comparison filter matches, for example, a value of thursday. The comparison is based on the order of the enumerated values, and ASCII values are not applicable in this case.