Handle PING requests.
$_driver : \Horde_ActiveSync_Driver_Base
Driver for communicating with the backend datastore.
$_state : \Horde_ActiveSync_State_Base
$_encoder : \Horde_ActiveSync_Wbxml_Encoder
$_decoder : \Horde_ActiveSync_Wbxml_Decoder
$_provisioning : integer
Whether we require provisioned devices.
Valid values are:
$_activeSync : \Horde_ActiveSync
$_device : \Horde_ActiveSync_Device
The device info
_handle() : boolean
Handle a PING command from the client. PING is sent periodically by the client to tell the server what folders we are interested in monitoring for changes. If no changes are detected by the server during the 'heartbeat' interval, the server sends back a status of self::STATUS_NOCHANGES to indicate heartbeat expired and the client should re-issue the PING command. If a change has been found, the client is sent a self::STATUS_NEEDSYNC and should issue a SYNC command.