NAME

       Net::LDAP::Control::VLV - LDAPv3 Virtual List View control object

SYNOPSIS

        use Net::LDAP;
        use Net::LDAP::Control::VLV;
        use Net::LDAP::Constant qw( LDAP_CONTROL_VLVRESPONSE );

        $ldap = Net::LDAP->new( "ldap.mydomain.eg" );

        # Get the first 20 entries
        $vlv  = Net::LDAP::Control::VLV->new(
                  before  => 0,        # No entries from before target entry
                  after   => 19,       # 19 entries after target entry
                  content => 0,        # List size unknown
                  offset  => 1,        # Target entry is the first
                );
        $sort = Net::LDAP::Control::Sort->new( order => 'cn' );

        @args = ( base     => "o=Ace Industry, c=us",
                  scope    => "subtree",
                  filter   => "(objectClass=inetOrgPerson)",
                  callback => \&process_entry, # Call this sub for each entry
                  control  => [ $vlv, $sort ],
        );

        $mesg = $ldap->search( @args );

        # Get VLV response control
        ($resp)  = $mesg->control( LDAP_CONTROL_VLVRESPONSE )  or die;
        $vlv->response( $resp );

        # Set the control to get the last 20 entries
        $vlv->end;

        $mesg = $ldap->search( @args );

        # Get VLV response control
        ($resp)  = $mesg->control( LDAP_CONTROL_VLVRESPONSE )  or die;
        $vlv->response( $resp );

        # Now get the previous page
        $vlv->scroll_page( -1 );

        $mesg = $ldap->search( @args );

        # Get VLV response control
        ($resp)  = $mesg->control( LDAP_CONTROL_VLVRESPONSE )  or die;
        $vlv->response( $resp );

        # Now page with first entry starting with "B" in the middle
        $vlv->before(9);       # Change page to show 9 before
        $vlv->after(10);       # Change page to show 10 after
        $vlv->assert("B");     # assert "B"

        $mesg = $ldap->search( @args );

DESCRIPTION

       "Net::LDAP::Control::VLV" provides an interface for the creation and manipulation of
       objects that represent the Virtual List View as described by
       draft-ietf-ldapext-ldapv3-vlv-09.txt.

       When using a Virtual List View control in a search, it must be accompanied by a sort
       control. See Net::LDAP::Control::Sort

CONSTRUCTOR ARGUMENTS

       In addition to the constructor arguments described in Net::LDAP::Control the following are
       provided.

       after
           Set the number of entries the server should return from the list after the target
           entry.

       assert
           Set the assertion value user to locate the target entry. This value should be a legal
           value to compare with the first attribute in the sort control that is passed with the
           VLV control. The target entry is the first entry in the list which is greater than or
           equal the assert value.

       before
           Set the number of entries the server should return from the list before the target
           entry.

       content
           Set the number of entries in the list. On the first search this value should be set to
           zero. On subsequent searches it should be set to the length of the list, as returned
           by the server in the VLVResponse control.

       context
           Set the context identifier.  On the first search this value should be set to zero. On
           subsequent searches it should be set to the context value returned by the server in
           the VLVResponse control.

       offset
           Set the offset of the target entry.

   METHODS
       As with Net::LDAP::Control each constructor argument described above is also available as
       a method on the object which will return the current value for the attribute if called
       without an argument, and set a new value for the attribute if called with an argument.

       The "offset" and "assert" attributes are mutually exclusive. Setting one or the other will
       cause previous values set by the other to be forgotten. The "content" attribute is also
       associated with the "offset" attribute, so setting "assert" will cause any "content" value
       to be forgotten.

       end Set the target entry to the end of the list. This method will change the "before" and
           "after" attributes so that the target entry is the last in the page.

       response VLV_RESPONSE
           Set the attributes in the control as per VLV_RESPONSE. VLV_RESPONSE should be a
           control of type Net::LDAP::Control::VLVResponse returned from the server. "response"
           will populate the "context", "offset" and "content" attributes of the control with the
           values from VLV_RESPONSE. Because this sets the "offset" attribute, any previous
           setting of the "assert" attribute will be forgotten.

       scroll NUM
           Move the target entry by NUM entries. A positive NUM will move the target entry
           towards the end of the list and a negative NUM will move the target entry towards the
           start of the list. Returns the index of the new target entry, or "undef" if the
           current target is identified by an assertion.

           "scroll" may change the "before" and "after" attributes if the scroll value would
           cause the page to go off either end of the list. But the page size will be maintained.

       scroll_page NUM
           Scroll by NUM pages. This method simple calculates the current page size and calls
           "scroll" with "NUM * $page_size"

       start
           Set the target entry to the start of the list. This method will change the "before"
           and "after" attributes to the target entry is the first entry in the page.

SEE ALSO

       Net::LDAP, Net::LDAP::Control, Net::LDAP::Control::Sort, Net::LDAP::Control::VLVResponse

AUTHOR

       Graham Barr <gbarr@pobox.com>

       Please report any bugs, or post any suggestions, to the perl-ldap mailing list
       <perl-ldap@perl.org>

COPYRIGHT

       Copyright (c) 2000-2004 Graham Barr. All rights reserved. This program is free software;
       you can redistribute it and/or modify it under the same terms as Perl itself.