Stream Management

As XMPP operates over persistent TCP connections, stream management provides mechanisms to handle interruptions and maintain session continuity, ensuring that messages and presence updates are delivered even in the face of network instability.

The integration of stream management in XMPP significantly enhances the user experience by providing a seamless communication flow. Users can engage in conversations without worrying about interruptions, ensuring that their messages are sent and received reliably.

If the server supports stream management, Whixp automatically attempts to enable stream resumption. When this feature is active, a resumption ID is stored in the local database for future reconnection. Should the stream resumption fail, Whixp will retry to enable it and request a new resumption ID. All of these processes occur automatically, so there’s no need for manual intervention.

Whixp also provides a handler for processing stanza acknowledgments (acks), which is primarily used in message handling. When you send a message to a recipient, the server does not immediately inform you of the message's delivery status. Instead, it sends a response stanza indicating that the message is on the server. At this point, you can consider the message as "sent." The actual delivery to the recipient is managed server-side, and this is further detailed in protocols such as XEP-0184: Message Receipts and XEP-0333: Displayed Markers. These extensions facilitate more granular control over message acknowledgment and delivery tracking, enhancing the overall messaging experience.

Handling acked stanzas

You can handle acknowledged stanzas through a specific event handler.

whixp.addEventHandler<Stanza>('ackedStanza', (stanza) {
    if (stanza is Message) {
      final stanzaIDs = stanza.get<StanzaID>();
      print('Message acked: ${stanzaIDs.first.id}');
    }
  });

The handler listens for the ackedStanza event, which is triggered when the server acknowledges a stanza.

This handler allows you to track all emitted stanzas, including Presence and IQ stanzas as well as Message stanzas.

You can also handle raw acknowledged stanzas using the ackedRaw event.

whixp.addEventHandler<String>(
    'ackedRaw',
    (stanza) => print('Acked raw: $stanza'),
  );