An extensible matching filter contains the following components:
- The OID of the matching rule to use for the determination. This is an optional element, and if it isn't provided then the attribute type must be given and its default equality matching rule will be used.
- The name of the AttributeType that will be targeted. If this is not provided, then all attributes contained in the entry will be examined.
- A flag that indicates whether the matching should be performed against the attributes of the entry's DN instead of the attributes contained in the entry.
- An assertion value that should be used as the target for the matching rule.
The string representation of an LDAP extensible match filter is comprised of the following components in order:
- An opening parenthesis
- The name of the attribute type, or an empty string if none was provided
- The string ":dn" if the dnAttributes flag is set, or an empty string if not
- If a matching rule ID is available, then a string comprised of a colon followed by that OID, or an empty string if there is no matching rule ID
- The string ":="
- The string representation of the assertion value
- A closing parenthesis