$Session Open: Difference between revisions
Jump to navigation
Jump to search
(Automatically generated page update) |
m (misc cleanup) |
||
| Line 2: | Line 2: | ||
<span class="pageSubtitle">Open a session</span> | <span class="pageSubtitle">Open a session</span> | ||
<p class="warn"><b>Note: </b> | <p class="warn"><b>Note:</b> Many $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $Session_Open function is <var>[[GetSession (Object subroutine)|GetSession]]</var>.</p> | ||
<var>$Session_Open</var> opens a previously created [[Sessions|session]]. | <var>$Session_Open</var> opens a previously created [[Sessions|session]]. | ||
==Syntax== | ==Syntax== | ||
| Line 11: | Line 10: | ||
</p> | </p> | ||
< | <table> | ||
<tr><th>%rc</th> | |||
<td>A returned zero, indicating success, or a number indicating the cause of error, if there is one.</td></tr> | |||
The | <tr><th>sesid</th> | ||
<td>The ID of the session to be opened. This is a required argument.</td></tr> | |||
The | <tr><th>owner</th> | ||
<td>The userid that owns the session to be opened. An <var class="term">owner</var> value of asterisk (<tt>*</tt>) means that the session is public, that is available to all users. | |||
<p> | |||
This optional argument defaults to the creating user's userid. </p></td></tr> | |||
The | <tr><th>timeout</th> | ||
<td>The time to wait for an in-use session to be closed before giving up. A value of -1 indicates to use the value of the <var>[[SRSDEFTO parameter|SRSDEFTO]]</var> parameter. This argument defaults to -1, that is, the value of the <var>SRSDEFTO</var> parameter.</td></tr> | |||
</table> | |||
===Return codes=== | ===Return codes=== | ||
| Line 28: | Line 35: | ||
==Usage notes== | ==Usage notes== | ||
Use of a non-zero timeout for <var>$Session_Open</var> can be useful for single-threading multiple threads through a request or for dealing with timing problems where it's possible for a request for a session to come in before the previous one is completely done. This is quite possible in <var class="product">[[Janus Web Server]]</var> applications where | Use of a non-zero timeout for <var>$Session_Open</var> can be useful for single-threading multiple threads through a request or for dealing with timing problems where it's possible for a request for a session to come in before the previous one is completely done. This is quite possible in <var class="product">[[Janus Web Server]]</var> applications where one of these occurs: | ||
<ul> | |||
<li>A request resulting from a redirect comes in before the redirecting thread has closed the session</li> | |||
<li>A user cancels a request and then resubmits it while the original request is still processing and so has the session open.</li> | |||
</ul> | |||
==Example== | ==Example== | ||
The following retrieves a session | The following retrieves a session ID from a cookie and opens it: | ||
<p class="code">% | <p class="code">%sesid = $Web_Get_Cookie('SESID') | ||
% | %rc = $Session_Open(%sesid) | ||
</p> | </p> | ||
Latest revision as of 22:48, 6 October 2015
Open a session
Note: Many $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $Session_Open function is GetSession.
$Session_Open opens a previously created session.
Syntax
%rc = $Session_Open(sesid, [owner], [timeout])
| %rc | A returned zero, indicating success, or a number indicating the cause of error, if there is one. |
|---|---|
| sesid | The ID of the session to be opened. This is a required argument. |
| owner | The userid that owns the session to be opened. An owner value of asterisk (*) means that the session is public, that is available to all users.
This optional argument defaults to the creating user's userid. |
| timeout | The time to wait for an in-use session to be closed before giving up. A value of -1 indicates to use the value of the SRSDEFTO parameter. This argument defaults to -1, that is, the value of the SRSDEFTO parameter. |
Return codes
%rc is set to 0 or to an error indicator.
0 - No errors 1 - Session not found 2 - Session in use
Usage notes
Use of a non-zero timeout for $Session_Open can be useful for single-threading multiple threads through a request or for dealing with timing problems where it's possible for a request for a session to come in before the previous one is completely done. This is quite possible in Janus Web Server applications where one of these occurs:
- A request resulting from a redirect comes in before the redirecting thread has closed the session
- A user cancels a request and then resubmits it while the original request is still processing and so has the session open.
Example
The following retrieves a session ID from a cookie and opens it:
%sesid = $Web_Get_Cookie('SESID') %rc = $Session_Open(%sesid)