WebSocket
The WebSocket object provides the API for creating and managing a
WebSocket connection to a server, as well as for sending and receiving
data on the connection.
See
https://developer.mozilla.org/docs/Web/API/WebSocket
Extends
Constructors
new WebSocket()
new WebSocket(url, protocols?): WebSocket
Creates a new WebSocket connection to the given URL.
Parameters
| Parameter | Type | Description |
|---|---|---|
url | string | URL | The URL to connect to. Must use ws: or wss: protocol. |
protocols? | string | string[] | Optional subprotocol(s) to request. |
Returns
Overrides
See
https://developer.mozilla.org/docs/Web/API/WebSocket/WebSocket
Properties
| Property | Modifier | Type | Default value |
|---|---|---|---|
CLOSED | readonly | 3 | CLOSED |
CLOSING | readonly | 2 | CLOSING |
CONNECTING | readonly | 0 | CONNECTING |
onclose | public | null | (this, ev) => any | null |
onerror | public | null | (this, ev) => any | null |
onmessage | public | null | (this, ev) => any | null |
onopen | public | null | (this, ev) => any | null |
OPEN | readonly | 1 | OPEN |
CLOSED | readonly | 3 | CLOSED |
CLOSING | readonly | 2 | CLOSING |
CONNECTING | readonly | 0 | CONNECTING |
OPEN | readonly | 1 | OPEN |
Accessors
binaryType
get binaryType(): BinaryType
The type of binary data being received over the connection.
See
https://developer.mozilla.org/docs/Web/API/WebSocket/binaryType
set binaryType(value): void
Parameters
| Parameter | Type |
|---|---|
value | BinaryType |
Returns
bufferedAmount
get bufferedAmount(): number
The number of bytes of data that have been queued using calls to send()
but not yet transmitted to the network.
See
https://developer.mozilla.org/docs/Web/API/WebSocket/bufferedAmount
Returns
number
extensions
get extensions(): string
The extensions selected by the server.
See
https://developer.mozilla.org/docs/Web/API/WebSocket/extensions
Returns
string
protocol
get protocol(): string
The sub-protocol selected by the server.
See
https://developer.mozilla.org/docs/Web/API/WebSocket/protocol
Returns
string
readyState
get readyState(): number
The current state of the connection.
See
https://developer.mozilla.org/docs/Web/API/WebSocket/readyState
Returns
number
url
get url(): string
The absolute URL of the WebSocket.
See
https://developer.mozilla.org/docs/Web/API/WebSocket/url
Returns
string
Methods
addEventListener()
addEventListener(type, callback, options?): void
Appends an event listener for events whose type attribute value is type. The callback argument sets the callback that will be invoked when the event is dispatched.
The options argument sets listener-specific options. For compatibility this can be a boolean, in which case the method behaves exactly as if the value was specified as options's capture.
When set to true, options's capture prevents callback from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE. When false (or not present), callback will not be invoked when event's eventPhase attribute value is CAPTURING_PHASE. Either way, callback will be invoked if event's eventPhase attribute value is AT_TARGET.
When set to true, options's passive indicates that the callback will not cancel the event by invoking preventDefault(). This is used to enable performance optimizations described in § 2.8 Observing event listeners.
When set to true, options's once indicates that the callback will only be invoked once after which the event listener will be removed.
If an AbortSignal is passed for options's signal, then the event listener will be removed when signal is aborted.
The event listener is appended to target's event listener list and is not appended if it has the same type, callback, and capture.
Parameters
| Parameter | Type |
|---|---|
type | string |
callback | null | EventListenerOrEventListenerObject<any> |
options? | boolean | AddEventListenerOptions |
Returns
void
Inherited from
See
https://developer.mozilla.org/docs/Web/API/EventTarget/addEventListener
close()
close(code?, reason?): void
Closes the WebSocket connection or connection attempt, if any.
Parameters
| Parameter | Type | Description |
|---|---|---|
code? | number | A numeric value indicating the status code. If not specified, 1000 is used. |
reason? | string | A human-readable string explaining why the connection is closing. |
Returns
void
See
https://developer.mozilla.org/docs/Web/API/WebSocket/close
dispatchEvent()
dispatchEvent(event): boolean
Dispatches a synthetic event event to target and returns true if either event's cancelable attribute value is false or its preventDefault() method was not invoked, and false otherwise.
Parameters
| Parameter | Type |
|---|---|
event | Event |
Returns
boolean
Inherited from
See
https://developer.mozilla.org/docs/Web/API/EventTarget/dispatchEvent
removeEventListener()
removeEventListener(type, callback, options?): void
Removes the event listener in target's event listener list with the same type, callback, and options.
Parameters
| Parameter | Type |
|---|---|
type | string |
callback | null | EventListenerOrEventListenerObject<any> |
options? | boolean | EventListenerOptions |
Returns
void
Inherited from
EventTarget.removeEventListener
See
https://developer.mozilla.org/docs/Web/API/EventTarget/removeEventListener
send()
send(data): void
Enqueues the specified data to be transmitted to the server over the WebSocket connection.
Parameters
| Parameter | Type | Description |
|---|---|---|
data | string | ArrayBufferLike | ArrayBufferView | Blob | The data to send: string, ArrayBuffer, ArrayBufferView, or Blob. |
Returns
void