WebSocket Module
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This XQuery Module contains functions for accessing specific WebSocket functions. This module is mainly useful in the context of WebSockets.
Contents
Conventions
- The
basex-api
package must be included in the classpath. This is always the case if you use one of the complete distributions (zip, exe, war) of BaseX. - All functions and errors are assigned to the
http://basex.org/modules/ws
namespace. The module must be imported in the query prolog:
import module namespace ws = "http://basex.org/modules/ws"; ...
Functions
ws:send
Signatures | ws:send($message as xs:anyAtomicType, $ids as xs:string*) as empty-sequence()
|
Summary | Sends a $message , which may be of type xs:string, xs:base64Binary or xs:hexBinary, to the users with the specified $ids .
|
ws:broadcast
Signatures | ws:broadcast($message as xs:anyAtomicType) as empty-sequence()
|
Summary | Broadcasts a $message , which may be of type xs:string, xs:base64Binary or xs:hexBinary, to all connected clients except to the caller.
|
ws:emit
Signatures | ws:emit($message as xs:anyAtomicType) as empty-sequence()
|
Summary | Emits a $message , which may be of type xs:string, xs:base64Binary or xs:hexBinary, to all connected clients.
|
ws:id
Signatures | ws:id() as xs:string
|
Summary | Returns the ID of the current WebSocket client. |
ws:ids
Signatures | ws:ids() as xs:string*
|
Summary | Returns the ids of all currently registered WebSocket clients. |
ws:path
Signatures | ws:path($id as xs:string) as xs:string
|
Summary | Returns the path of the WebSocket client with the specified $id .
|
ws:close
Signatures | ws:close($id as xs:string) as empty-sequence()
|
Summary | Closes the connection of the WebSocket client with the specified $id .
|
Examples
Example 1
import module namespace ws = "http://basex.org/modules/Websocket"; declare %ws:connect('/') function local:connect() as xs:string { let $id := ws:id() let $message := json:serialize(map { 'type': 'Connect', 'id': $id }) return ws:broadcast($message) };
Explanation:
- The function has a
%ws:connect
annotation. It gets called if a client successfully creates a WebSocket connection to the path/
(check out WebSockets for further information). - A JSON response is generated, which contains the new client id and a
Connect
string. - This response will be sent to all other connected clients.
Example 2
import module namespace ws = "http://basex.org/modules/Websocket"; declare %ws:message('/', '{$message}') function local:message( $message as xs:string ) as xs:string { let $message := json:serialize(map { 'message': $message }) return ws:emit($message) };
Explanation:
- The function has a
%ws:message
annotation. It gets called if a client sends a new message. - A JSON response is generated, which contains the message string.
- This response will be sent to all connected clients (including the calling client).