[imp] Setting up an authentication chain in Horde

[SSRI]

Hello,

Horde composite driver can't handle a specific driver for CalDAV,  
WedDAV,  Free/Busy URL ... So, we have set up this test in  
config/conf.local.php :

if ( Horde_Cli::runningFromCLI() ||
      preg_match('|^/horde/rpc.php|',$_SERVER['REQUEST_URI']) ||
      preg_match('|^/horde/kronolith/fb.php|',$_SERVER['REQUEST_URI']) ||
...

    ) {
     $conf['auth']['driver'] = 'ldap';
} else {

     $conf['auth']['driver'] = 'custom_driver';
}

Is there a way for Horde to set up an authentication chain ( if the  
ldap drivers fails, automatically fall back to custom_driver ) ?

SSRI Team
IT Services - Université Pantheon-Assas ( Paris 2 )