oof: Content from Server
The oof message indicates that a message in the SOW that previously matched the subscription is no longer in focus. For more information, see the Out of Focus Messages (OOF) chapter in the AMPS User Guide.
Header Fields
The following table contains the header fields returned in an oof message. Notice that the wire format of the message may abbreviate these field names or encode them differently:
| Field | Description |
|---|---|
cmd | Type of message. Always |
topic | The topic which contained the message that has gone out of focus. |
msg_len | The length of the message body. |
sow_key | An AMPS-created identifier for the message that has gone out of focus. |
reason | The reason the message has gone out of focus. Valid reasons include |
sids | The subscription IDs of the subscriptions that produced this message. The AMPS clients will provide this message to the handler registered for each of the subscriptions specified. |
correlation_id | A user-provided string that will be passed, verbatim, to subscribers. If this header is not present on the SOW record that was deleted, subscribers receive no value for the The contents of this header must consist of characters that are legal in Base64 encoding. |
Reason
The reason field of the oof message explains why the message no longer matches the subscription. Possible values are:
| Reason | Description |
|---|---|
deleted | The message was deleted. |
expired | The message expired. |
match | The message no longer matches the filter for the subscription or (for paginated subscriptions) no longer matches the pagination window. |
entitlement | The access to the messaged changed, such that the user no longer has permission to receive the message. |
Data
The oof message contains the updated message that caused the message to go out of focus when the reason is match. Otherwise, this connection does not have permission to see the updated message (if the reason is entitlement) or there is no updated message to provide (if the reason is deleted or expired). The previous message will be provided for reasons other than match.