class %CSP.WebSocket
extends %RegisteredObject, %CSP.Page
The %CSP.WebSocket object serves as an event handler for communication between client and
server using the WebSocket protocol (RFC 6455). All WebSocket servers derive from %CSP.WebSocket.
• parameter NOCHARSETCONVERT = 1;
Specifies if we wish to turn off charset conversion for this page. Normally CSP uses
the tables built into InterSystems IRIS to convert between different charset's, however if you
do not have a charset available you may wish to turn this off to avoid getting the
error page saying that this charset is not installed. Then the data will be output
and read in using RAW mode. This can be overridden using the <CSP:CONTENT NOCHARSETCONVERT=1>
tag, or by setting the %response.NoCharSetConvert property in the
OnPreHTTP method.
• parameter UseSession = 0;
This parameter controls the CSP session support. By default CSP will use a persistent session
which holds a license until the session is ended or times out. If you override this then this
CSP page will use a transient session which is never persisted.
• property AtEnd
as %Boolean [ InitialExpression = 1 ];
The AtEnd property is set to true (1) when, during a read,
the WebSocket server has reached the end of the current data frame.
• property BinaryData
as %Boolean [ InitialExpression = 0 ];
This property determines whether the data streams transmitted between the client and server should be treated as binary.
The default setting is to treat the incoming and outgoing data as UTF-8 encoded text.
This property may be set to one of the following:
- BinaryData=0 - UTF-8 encoded text.
- BinaryData=1 - Binary Data.
• property GWClientAddress
as %String;
The address through which a WebSocket operating asynchronously (SharedConnection=1) can communicate with the hosting CSP Gateway.
• property NoDataFraming
as %Boolean [ InitialExpression = 0 ];
This property determines whether formal data framing should occur between the Web Gateway and InterSystems IRIS
- NoDataFraming=0 - Use the READ and WRITE methods in this class to manage I/O with the WebSocket.
- NoDataFraming=1 - Use the basic ObjectScript READ and WRITE commands to manage I/O with the WebSocket (SharedConnection cannot be set with this mode).
• property SessionId
as %String;
The CSP Session ID from which this WebSocket was created.
• property SharedConnection
as %Boolean [ InitialExpression = 0 ];
This property determines whether the communication between the client and WebSocket server should be over a dedicated Gateway
conection or over a pool of shared connections. It may be set to one of the following:
- SharedConnection=0 - The WebSocket server communicates with the client via a dedicated Gateway connection. In this mode of operation the hosting connection is effectively 'private' to the application session.
- SharedConnection=1 - The WebSocket server communicates asynchronously with the client via a fixed number of shared Gateway connections.
• property WebSocketID
as %String;
The unique identity of this WebSocket.
• method EndServer()
as %Status
Gracefully terminate the WebSocket Server.
• method Initialize(WebSocketID As %String = "", GWClientAddress As %String = "")
as %Status
Internal method to initialize the WebSocket Class.
• method InitializeServer()
as %Status
Internal method to initialize the WebSocket Server.
• method OnClientMessage(data As %String = "", close As %Integer)
as %Status
Event handler for the ClientMessage event: this method is only relevant to
WebSockets operating in Asynchronous mode. In other words Websockets for which
the SharedConnection flag is set.
If OnClientMessage successfully processes the client message it
must return with $$$OK
• method OnPostServer()
as %Status
Event handler for the PostServer event: this is invoked after
closing the WebSockets Server.
• method OnPreServer()
as %Status
Event handler for the PreServer event: this is invoked before
starting the WebSockets Server.
Changes to the SharedConnection flag must be made here.
• method OpenServer(WebSocketID As %String = "")
as %Status
Method to open an existing WebSocket Server.
Only a WebSocket operating asynchronously (SharedConnection=1) can be accessed using this method.
• method Read(ByRef len As %Integer = 32656, ByRef sc As %Status, timeout As %Integer = 86400)
as %String
Reads up to len characters from the client.
If the call is successful the status (sc) will be returned as $$$OK, otherwise an error code of $$$CSPWebSocketTimeout
indicates a timeout and $$$CSPWebSocketClosed indicates that the client has terminated the WebSocket.
• method Server()
as %Status
The WebSocket Server. Use the Read and Write methods
to receive data from, and send data to, the client.
Call the EndServer method to gracefully terminate the WebSocket Server.
A WebSocket operating asynchronously (SharedConnection=1) can exit this method (using Quit) and subsequently open the WebSocket using the OpenServer method.
• method Write(data As %String)
as %Status
Write to the client.
