RealtimeMessage class

Wire message envelope shared between Bloom Realtime client and server.

Encapsulates message framing across WebSockets or server-sent events. Pure Dart, requiring only dart:convert, ensuring compatibility across Dart VM, SSR, and client runtimes.

Message Types

Channel subscription: typeSubscribe, typeUnsubscribe
Broadcast events: typeBroadcast
Presence tracking: typePresenceJoin, typePresenceLeave, typePresenceState
System heartbeats and diagnostics: typePing, typePong, typeError

Example

// Construct a broadcast message
final msg = RealtimeMessage.broadcast('chat:general', {'text': 'Hello, world!'});
final jsonString = msg.encode();

// Parse incoming wire message
final parsed = RealtimeMessage.tryParse(jsonString);
if (parsed != null && parsed.type == RealtimeMessage.typeBroadcast) {
  print('Message on ${parsed.channel}: ${parsed.payload}');
}

Constructors

RealtimeMessage({required String type, String? channel, Map<String, dynamic> payload = const {}}): Creates a RealtimeMessage envelope.
const
RealtimeMessage.broadcast(String channel, Map<String, dynamic> payload): Creates a broadcast event message on channel with the given payload.
factory
RealtimeMessage.error(String message, {String? channel, String? code}): Creates an error message envelope.
factory
RealtimeMessage.fromJson(Map<String, dynamic> json): Deserializes a RealtimeMessage from a decoded JSON map.
factory
RealtimeMessage.ping(): Creates a ping keep-alive heartbeat message.
factory
RealtimeMessage.pong(): Creates a pong keep-alive heartbeat response message.
factory
RealtimeMessage.presenceJoin(String channel, Map<String, dynamic> userInfo): Creates a presence join message announcing userInfo metadata in channel.
factory
RealtimeMessage.presenceLeave(String channel, Map<String, dynamic> userInfo): Creates a presence leave message announcing that a user left channel.
factory
RealtimeMessage.presenceState(String channel, List<Map<String, dynamic>> presences): Creates a presence state snapshot message containing all active presences in channel.
factory
RealtimeMessage.subscribe(String channel): Creates a subscription message targeting channel.
factory
RealtimeMessage.unsubscribe(String channel): Creates an unsubscription message targeting channel.
factory

Properties

channel → String?: Channel identifier (e.g. 'lists:42', 'presence:room-1').
final
hashCode → int: The hash code for this object.
no setterinherited
payload → Map<String, dynamic>: Payload map associated with the event.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
type → String: Message type identifier (e.g. 'subscribe', 'broadcast', 'presence_join').
final

Methods

encode() → String: Encodes this message to a JSON string.
encodeBytes() → List<int>: Encodes this message to a UTF-8 byte buffer for binary frame transmission.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toJson() → Map<String, dynamic>: Serializes this message to a JSON-compatible map.
toString() → String: A string representation of this object.
override

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

tryParse(dynamic raw) → RealtimeMessage?: Attempts to parse raw (a JSON string, UTF-8 byte list, or Map) into a RealtimeMessage.

Constants

typeBroadcast → const String: Wire action type indicating an arbitrary event broadcast to channel subscribers.
typeError → const String: Wire action type indicating a server-side or protocol error.
typePing → const String: Wire heartbeat ping message.
typePong → const String: Wire heartbeat pong response.
typePresenceJoin → const String: Wire action type indicating a client joined channel presence.
typePresenceLeave → const String: Wire action type indicating a client left channel presence.
typePresenceState → const String: Wire action type carrying the full snapshot of active channel presences.
typeSubscribe → const String: Wire action type indicating a channel subscription request.
typeUnsubscribe → const String: Wire action type indicating an unsubscription request.