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Session

Session : 4D.Session

ParameterTypeDescription
Function result4D.Session←Session object
History
ReleaseChanges
20 R8Support of standalone sessions
20 R5Support of remote client and stored procedure sessions
18 R6Added

Description​

The Session command returns the Session object corresponding to the current session.

Depending on the process from which the command is called, the current session can be:

For more information, see the Session types paragraph.

The command returns Null if:

  • it is called in a web process and scalable sessions are disabled on the web server,
  • it is called on a remote 4D client.

Web sessions​

The Session object of web sessions is available from any web process:

  • On Web Authentication, On Web Connection, and On REST Authentication database methods,
  • code processed through 4D tags in semi-dynamic pages (4DTEXT, 4DHTML, 4DEVAL, 4DSCRIPT/, 4DCODE)
  • project methods with the "Available through 4D tags and URLs (4DACTION...)" attribute and called through 4DACTION/ urls,
  • On Mobile App Authentication and On Mobile App Action database methods for mobile requests,
  • ORDA functions called with REST requests.

For more information on web user sessions, please refer to the Web Server Sessions section.

Remote user sessions​

The Session object of remote user sessions is available from:

  • Project methods that have the Execute on Server attribute (they are executed in the "twinned" process of the client process),
  • Triggers,
  • ORDA data model functions (except those declared with the local keyword,
  • On Server Open Connection and On Server Shutdown Connection database methods.

For more information on remote user sessions, please refer to the Remote user sessions paragraph.

Stored procedures session​

All stored procedure processes share the same virtual user session. The Session object of stored procedures is available from:

  • methods called with the Execute on server command,
  • On Server Startup, On Server Shutdown, On Backup Startup, On Backup Shutdown, and On System event database methods

For more information on stored procedures virtual user session, please refer to the Stored procedure sessions paragraph.

Standalone session​

The Session object is available from any process in standalone (single-user) applications so that you can write and test your client/server code using the Session object in your 4D development environment.

For more information on standalone sessions, please refer to the Standalone sessions paragraph.

Session and components​

When Session is called from the code of different components loaded in the project, the command returns an object depending on the calling request and the context:

  • in case of a web request, Session always returns the session attached to the target web server of the request (and not a session of the component's web server),
  • in case of a remote request executed on the server, Session always returns the session attached to the remote user,
  • in case of a stored procedure session or a standalone session, Session always returns the single current session (the same object is used during all the work session).

Example​

You have defined the action_Session method with attribute "Available through 4D tags and URLs". You call the method by entering the following URL in your browser:

IP:port/4DACTION/action_Session
  //action_Session method
 Case of
    :(Session#Null)
       If(Session.hasPrivilege("CreateInvoices")) //calling the hasPrivilege function
          WEB SEND TEXT("4DACTION --> Session is CreateInvoices")
       Else
          WEB SEND TEXT("4DACTION --> Session is not CreateInvoices")
       End if
    Else
       WEB SEND TEXT("4DACTION --> Session is null")
 End case

See also​

Session storage
Session API Desktop sessions Web server user sessions
Scalable sessions for advanced web applications (blog post)

Properties​

Command number1714
Thread safeyes