Handling sequences for synchronization rules

The class SequencesFactory offers 2 main methods, available from all Javascript contexts.

Sequences are handled by updatable entries inside the directory, thus getting a new value will increment the attribute that is used as a counter.

Java object is documented there: SequencesFactory

Reading the current value

To read the current sequence value, just call the getCurrentValue(DN, Attribute) method.

If an error is encountered, the call will return the -1 value.

Getting the next value

To get the next value, just call the getNextValue(DN, Attribute) method on the sequence.

If an error is encountered, the call will return the -1 value.

But the next call to the same method will return an incremented value because each time the method is called, the directory value will be updated!

Sample

Let just imagine that you need to handle the uidNumber value inside a directory.

First create somewhere inside your directory the following entry:

dn: cn=uidNumberSequence,ou=Sequences,ou=HiddenTree,dc=lsc-project,dc=org
cn: uidNumberSequence
objectClass: device
objectClass: top
serialNumber: 1024

Then inside the task settings, inside the propertiesBasedSyncOptions node, add the following XML elements to specify the previous entry:

<dataset>
    <name>uidNumber</name>
    <policy>KEEP</policy>
    <defaultValues>
        <string>
            SequencesFactory.getInstance(ldap.getJndiServices()).
            getNextValue("cn=uidNumberSequence,ou=Sequences,ou=HiddenTree,dc=lsc-project,dc=org",
                         "serialNumber")
        </string>
    </defaultValues>
</dataset>

Take care to the following items:

• always use a KEEP policy, because otherwise the counter will increment each time an object is synchronized even if the object is not updated !

• you can either specify that the sequence will be looked up inside the source or the destination directory respectively with on the srcLdap.getJndiServices() or ldap.getJndiServices()