WebSocket Server


Version Not Yet Released

You are viewing the documentation for the 1.x branch of the WebSocket Server package which has not yet been released. Be aware that the API for this version may change before release.


Connections to the websocket server are represented by the BabDev\WebSocket\Server\Connection interface.

At their core, a connection has two primary responsibilities:

  • Send messages from the server to a connected client
  • Store arbitrary data for the connection

During the message lifecycle, the connection object will be decorated by BabDev\WebSocket\Server\WebSocket\WebSocketConnection and BabDev\WebSocket\Server\WAMP\WAMPConnection implementations which assist in handling all WAMP server-to-client messages and resolving URIs for incoming messages.

Attribute Store

Each connection has a BabDev\WebSocket\Server\Connection\AttributeStore attached to it and allows storing arbitrary data for the connection. During the connection lifecycle, several pieces of data will be added to the store by the middleware provided by this package. The below keys are reserved for specific purposes and should not be replaced:

Key Data Description
http.buffer string Temporary storage for the incoming HTTP request body (this buffer is cleared once the full body is received)
http.headers_received boolean Internal flag tracking whether the HTTP headers have been received and parsed
http.request PSR-7 Psr\Http\Message\RequestInterface The fully parsed HTTP request body
remote_address string The remote address for the connected client, if available
resource_id integer An identifier for the underlying connection resource
session Symfony\Component\HttpFoundation\Session\SessionInterface When using the session middleware, the session is initialized into a SessionInterface implementation
wamp.session_id string A unique, randomly generated, identifier for the connection
wamp.subscriptions SplObjectStorage<BabDev\WebSocket\Server\WAMP\Topic, null> A list of topics (PubSub channels) that the connection is currently subscribed to
wamp.prefixes array<string, string> An associative array storing the list of prefixes for the connection, as configured by the "PREFIX" WAMP message
websocket.closing boolean Internal flag tracking if the connection is being closed; once set to true, no further messages will be sent to the client

Client Communication

The connection object exposes two methods to communicate with a connected client: send() and close()

The BabDev\WebSocket\Server\Connection::send() method can send any data string to the connected client. Generally, this should be an RFC6455 compliant message with a WAMP v1 compliant payload.

The BabDev\WebSocket\Server\Connection::close() method is used to close a client connection, optionally sending a final message. Generally, the close message should be an RFC6455 compliant close control frame.

Extended Connections

WebSocket Connection

The BabDev\WebSocket\Server\WebSocket\WebSocketConnection interface extends the core connection interface to add extended messaging support.

Specifically, this interface extends the connection's send() method to support sending either any data string or a Ratchet\RFC6455\Messaging\DataInterface object from the ratchet/rfc6455 package. This is beneficial for applications to have full control over the data frames sent to the client (i.e. to support sending binary data). Please review the package's documentation for additional usage details.

WAMP Connection

The BabDev\WebSocket\Server\WAMP\WAMPConnection interface extends the WebSocket connection interface and adds methods to support WAMP server-to-client messages, as well as providing the URI resolver for CURIEs.

The callResult(), callError(), event(), and prefix() methods correspond to the WAMP server-to-client message types and are used to send RPC call results to the caller or broadcast events.

The getUri() method is used to resolve URIs for incoming messages and provides support for registered prefixes for the CURIE protocol.