Envelope Fields

Envelope Field	Event Editor Type	Description
age	long	The time in seconds since the event was received by the Broker.
appLastSeqn	int	The sequence number of the last event in the sequence. Your application defines how this field is used. The conventional way to use this field is to set it to 0 if you do not know the last sequence number. By specifying the last in the sequence, the recipient knows how many events to expect.
appPassword	unicode_string	Represents a user's password.
appSeqn	int	The sequence number, set by the event's publisher. Your application defines how this field is used. The conventional way to use this field is to count upward from 1.
appUsername	unicode_string	Represents a user's name.
controlLabel	short[]	Represents the access label that a receiving client must have to receive the event. See awSetClientAutomaticControlLabel for more information.
errorsTo	unicode_string	The client ID to which the event should be forwarded if any errors are generated when this event should be sent, instead of sending to the originator of the request.
errorRequestsTo	unicode_string	The client ID to which a request event will be forwarded if any errors generated processing the request. If field is not set, any request event that generates an error will be discarded.
maxResults	int	The maximum number of reply events a requestor would like to receive. A value of 0 indicates that no reply or acknowledgment should be sent for this event.
replyTo	unicode_string	The client ID to which the replies to this event should be sent, instead of sending to the originator of the request.
signature	byte[]	A byte sequence that holds a digital signature.
signatureType	unicode_string	Describes the type of digital signature being used.
startResult	int	A value >= 0 that specifies the starting number of the event to receive. Often used in conjunction with maxResults.
tag	int	Used in the request-reply model, described in Using Request-Reply, to match a request event with its corresponding reply event.
trackId	unicode_string	This field's value can be set by a publishing client application to a unique identifier for tracking purposes. This allows an event that is republished to be tracked. It also allows multiple events associated with a single logical transaction to be tracked. If not set, this field should be treated as if it contained the same value as the pubId field.
transactionId	unicode_string	This field's value can be set by a publishing client application to indicate that an event is part of a transaction. See Transactional Client Processing with Adapters for more information.
transformState	unicode_string	This field allows clients that transform data to mark an event's current state. An event could be published with a transformState value of USEnglish. A receiving client could translate the event into French and publish it with a transformState value of French.

The appSeqn and applastSeqn can be used by your publisher and subscriber applications for whatever purpose they require. One possibility is to track a sequence of events which represent a response to a single request event. Your publisher could start appSeqn at 1 and set appLastSeqn to the sequence number of the last event in the sequence. If your publisher does not know the length of the sequence when it starts publishing, then appLastSeqn need not be set. When your publisher is about to publish the last event of the sequence, appLastSeqn could be set to equal appSeqn. Setting both appSeqn and appLastSeqn are set to -1 indicates the event is empty.