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This is the latest (unstable) version of this documentation, which may document features not available in or compatible with released stable versions of Godot.

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WebSocket

HTML5 et WebSocket

Le protocole WebSocket a été normalisé en 2011 dans le but initial de permettre aux navigateurs de créer des connexions stables et bidirectionnelles avec un serveur. Avant cela, les navigateurs ne prenaient en charge que HTTPRequests, ce qui n'est pas bien adapté à la communication bidirectionnelle.

The protocol is message based and a very powerful tool to send push notifications to browsers, and has been used to implement chats, turn-based games, etc. It still uses a TCP connection, which is good for reliability but not for latency, so not good for real-time applications like VoIP and fast-paced games (see WebRTC for those use cases).

En raison de sa simplicité, de sa grande compatibilité et de sa facilité d'utilisation par rapport à une connexion TCP brute, WebSocket a rapidement commencé à se répandre en dehors des navigateurs, dans les applications natives, comme moyen de communication avec les serveurs réseau.

Godot supporte WebSocket en natif et en exportation HTML5.

Utilisation de WebSocket dans Godot

WebSocket is implemented in Godot via WebSocketPeer. The WebSocket implementation is compatible with the High-Level Multiplayer. See section on high-level multiplayer for more details.

Avertissement

Lors de l'exportation vers Android, assurez-vous d'activer la permission INTERNET dans le préréglage d'exportation Android avant d'exporter le projet ou d'utiliser le déploiement en un clic. Sinon, toute communication réseau sera bloquée par Android.

Exemple de client minimal

Cet exemple vous montrera comment créer une connexion WebSocket à un serveur distant, et comment envoyer et recevoir des données.

extends Node

# The URL we will connect to.
@export var websocket_url = "wss://echo.websocket.org"

# Our WebSocketClient instance.
var socket = WebSocketPeer.new()

func _ready():
    # Initiate connection to the given URL.
    var err = socket.connect_to_url(websocket_url)
    if err != OK:
        print("Unable to connect")
        set_process(false)
    else:
        # Wait for the socket to connect.
        await get_tree().create_timer(2).timeout

        # Send data.
        socket.send_text("Test packet")

func _process(_delta):
    # Call this in _process or _physics_process. Data transfer and state updates
    # will only happen when calling this function.
    socket.poll()

    # get_ready_state() tells you what state the socket is in.
    var state = socket.get_ready_state()

    # WebSocketPeer.STATE_OPEN means the socket is connected and ready
    # to send and receive data.
    if state == WebSocketPeer.STATE_OPEN:
        while socket.get_available_packet_count():
            print("Got data from server: ", socket.get_packet().get_string_from_utf8())

    # WebSocketPeer.STATE_CLOSING means the socket is closing.
    # It is important to keep polling for a clean close.
    elif state == WebSocketPeer.STATE_CLOSING:
        pass

    # WebSocketPeer.STATE_CLOSED means the connection has fully closed.
    # It is now safe to stop polling.
    elif state == WebSocketPeer.STATE_CLOSED:
        # The code will be -1 if the disconnection was not properly notified by the remote peer.
        var code = socket.get_close_code()
        print("WebSocket closed with code: %d. Clean: %s" % [code, code != -1])
        set_process(false) # Stop processing.

This will print something similar to:

Got data from server: Request served by 7811941c69e658
Got data from server: Test packet

Exemple de serveur minimal

Cet exemple vous montrera comment créer un serveur WebSocket qui écoute les connexions distante, et comment envoyer et recevoir des données.

extends Node

# The port we will listen to
const PORT = 9080
# Our WebSocketServer instance
var _server = WebSocketServer.new()

func _ready():
    # Connect base signals to get notified of new client connections,
    # disconnections, and disconnect requests.
    _server.client_connected.connect(_connected)
    _server.client_disconnected.connect(_disconnected)
    _server.client_close_request.connect(_close_request)
    # This signal is emitted when not using the Multiplayer API every time a
    # full packet is received.
    # Alternatively, you could check get_peer(PEER_ID).get_available_packets()
    # in a loop for each connected peer.
    _server.data_received.connect(_on_data)
    # Start listening on the given port.
    var err = _server.listen(PORT)
    if err != OK:
        print("Unable to start server")
        set_process(false)

func _connected(id, proto):
    # This is called when a new peer connects, "id" will be the assigned peer id,
    # "proto" will be the selected WebSocket sub-protocol (which is optional)
    print("Client %d connected with protocol: %s" % [id, proto])

func _close_request(id, code, reason):
    # This is called when a client notifies that it wishes to close the connection,
    # providing a reason string and close code.
    print("Client %d disconnecting with code: %d, reason: %s" % [id, code, reason])

func _disconnected(id, was_clean = false):
    # This is called when a client disconnects, "id" will be the one of the
    # disconnecting client, "was_clean" will tell you if the disconnection
    # was correctly notified by the remote peer before closing the socket.
    print("Client %d disconnected, clean: %s" % [id, str(was_clean)])

func _on_data(id):
    # Print the received packet, you MUST always use get_peer(id).get_packet to receive data,
    # and not get_packet directly when not using the MultiplayerAPI.
    var pkt = _server.get_peer(id).get_packet()
    print("Got data from client %d: %s ... echoing" % [id, pkt.get_string_from_utf8()])
    _server.get_peer(id).put_packet(pkt)

func _process(delta):
    # Call this in _process or _physics_process.
    # Data transfer, and signals emission will only happen when calling this function.
    _server.poll()

Cela imprimera (lorsqu'un client se connecte) quelque chose de similaire à ceci :

Client 1348090059 connected with protocol: selected-protocol
Got data from client 1348090059: Test packet ... echoing

Démonstration de chat avancée

A more advanced chat demo which optionally uses the multiplayer mid-level abstraction and a high-level multiplayer demo are available in the godot demo projects under networking/websocket_chat and networking/websocket_multiplayer.