A CloseEvent
is sent to clients using WebSockets when the connection is closed. This is delivered to the listener indicated by the WebSocket
object's onclose
attribute.
Constructor
CloseEvent()
- Creates a new
CloseEvent
.
Properties
This interface also inherits properties from its parent, Event
.
CloseEvent.code
Read only- Returns an
unsigned short
containing the close code send by the server. The following values are permitted status codes.Status code Name Description 0
–999
Reserved and not used. 1000
CLOSE_NORMAL
Normal closure; the connection successfully completed whatever purpose for which it was created. 1001
CLOSE_GOING_AWAY
The endpoint is going away, either because of a server failure or because the browser is navigating away from the page that opened the connection. 1002
CLOSE_PROTOCOL_ERROR
The endpoint is terminating the connection due to a protocol error. 1003
CLOSE_UNSUPPORTED
The connection is being terminated because the endpoint received data of a type it cannot accept (for example, a text-only endpoint received binary data). 1004
Reserved. A meaning might be defined in the future. 1005
CLOSE_NO_STATUS
Reserved. Indicates that no status code was provided even though one was expected. 1006
CLOSE_ABNORMAL
Reserved. Used to indicate that a connection was closed abnormally (that is, with no close frame being sent) when a status code is expected. 1007
Unsupported Data The endpoint is terminating the connection because a message was received that contained inconsistent data (e.g., non-UTF-8 data within a text message). 1008
Policy Violation The endpoint is terminating the connection because it received a message that violates its policy. This is a generic status code, used when codes 1003 and 1009 are not suitable. 1009
CLOSE_TOO_LARGE
The endpoint is terminating the connection because a data frame was received that is too large. 1010
Missing Extension The client is terminating the connection because it expected the server to negotiate one or more extension, but the server didn't. 1011
Internal Error The server is terminating the connection because it encountered an unexpected condition that prevented it from fulfilling the request. 1012
Service Restart The server is terminating the connection because it is restarting. [Ref] 1013
Try Again Later The server is terminating the connection due to a temporary condition, e.g. it is overloaded and is casting off some of its clients. [Ref] 1014
Reserved for future use by the WebSocket standard. 1015
TLS Handshake Reserved. Indicates that the connection was closed due to a failure to perform a TLS handshake (e.g., the server certificate can't be verified). 1016
–1999
Reserved for future use by the WebSocket standard. 2000
–2999
Reserved for use by WebSocket extensions. 3000
–3999
Available for use by libraries and frameworks. May not be used by applications. Available for registration at the IANA via first-come, first-serve. 4000
–4999
Available for use by applications. CloseEvent.reason
Read only- Returns a
DOMString
indicating the reason the server closed the connection. This is specific to the particular server and sub-protocol. CloseEvent.wasClean
Read only- Returns a
Boolean
that Indicates whether or not the connection was cleanly closed.
Methods
This interface also inherits methods from its parent, Event
.
CloseEvent.initCloseEvent()
- Initializes the value of a
CloseEvent
created. If the event has already being dispatched, this method does nothing. Do not use this method anymore, use theCloseEvent()
constructor instead.
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | ? | 8.0 (8.0)[1] 12.0 (12.0)[2] |
10 | ? | ? |
initCloseEvent () |
Not supported | 8.0 (8.0) Not supported 41.0 |
Not supported | Not supported | Not supported |
Feature | Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|
Basic support | ? | 8.0 (8.0) | ? | ? | ? |
initCloseEvent () |
Not supported | 8.0 (8.0) Not supported 41.0 |
Not supported | Not supported | Not supported |
[1] Prior to Gecko 8.0 (Firefox 8.0 / Thunderbird 8.0 / SeaMonkey 2.5), Gecko sent the WebSocket close
event to the listener as a simple event. Support for CloseEvent
was implemented in Gecko 8.0.
[2] Prior to Gecko 12.0 (Firefox 12.0 / Thunderbird 12.0 / SeaMonkey 2.9), Gecko reported the close code CLOSE_NORMAL
when the channel was closed due to an unexpected error, or if it was closed due to an error condition that the specification doesn't cover. Now CLOSE_GOING_AWAY
is reported instead.