WebSocket

Definition

[h2]var webSocket = new WebSocket(url, [protocol] );

• Description

  Creates a WebSocket object.

• Parameters

  Parameter	Type	Mandatory	Description
  url	string	Yes	URL of the connection.
  protocol	array	No	Supported subprotocol.

• Sample code

  createWebSocket(item, url, request, response, protocol, cert) {
          let ws = new WebSocket(url, protocol, cert);
          ws.onopen = function () {
              item.addEvent("open");
              request(ws);
          };
          ws.onmessage = function (evt) {
              item.addEvent("message");
              response(evt.data);
          };
          ws.onerror = function (evt) {
              item.addEvent("error");
              item.setState(TEST_STATE.ERROR);
          };
          ws.onclose = function () {
              item.addEvent("close");
          };
          item.setState(TEST_STATE.RUNNING);
          return ws;
      }

[h2]close(code, reason)

• Description

  Closes a WebSocket connection.

• Parameters

  Parameter	Type	Mandatory	Description
  code	number	No	WebSocket connection closing status. The value is a number.
  reason	string	No	Reason for closing a WebSocket connection. The value is a readable string.

[h2]send(data)

• Description

  Sends data.

• Parameters

  Parameter	Type	Mandatory	Description
  data	string/arraybuffer	Yes	Content to be sent.

[h2]webSocket.binaryType

• Description

  Explicitly specifies the type of the received binary data. The value can be blob or arraybuffer.

[h2]webSocket.bufferedAmount

• Description

  Obtains the number of remaining bytes to be sent.

[h2]webSocket.extensions

• Description

  Obtains the extensions supported by the server.

[h2]webSocket.onclose = callback

• Description

  Listens for WebSocket connection closing events.

• Parameters

  Parameter	Type	Mandatory	Description
  callback	function	Yes	Callback function for WebSocket connection closing events.

[h2]webSocket.onopen = callback

• Description

  Listens for WebSocket connection opening events.

• Parameters

  Parameter	Type	Mandatory	Description
  callback	function	Yes	Callback function for WebSocket connection opening events.

[h2]webSocket.onmessage = callback

• Description

  Listens for events that messages are received through the WebSocket connection from the server.

• Parameters

  Parameter	Type	Mandatory	Description
  callback	function	Yes	Event triggered when a message from the server is received through the WebSocket connection.

  • Parameters in callback

    Parameter	Type	Description
    data	string/arraybuffer	Message returned by the server.

[h2]webSocket.onerror = callback(errMsg)

• Description

  Listens for WebSocket error events.

• Parameters

  Parameter	Type	Mandatory	Description
  callback	function	Yes	Callback function for WebSocket error events.

  • Parameters in callback

    Parameter	Type	Description
    errMsg	string	Error message.

[h2]webSocket.protocol

• Description

  Returns the protocol used by the instance.

[h2]webSocket.readyState

• Description

  Returns the current status code of the instance.

• Status codes

  Status Code	Value	Description
  CONNECTING	0	Connecting.
  OPEN	1	The connection is successful and ready for communication.
  CLOSING	2	The connection is being closed.
  CLOSED	3	The connection is closed or fails to be opened.

[h2]webSocket.url

• Description

  Returns the URL of the connection.