$Web

Determine whether running a web request

$Web indicates whether the current processing is the result of a request to Janus Web Server.

$Web takes no arguments and returns either a 0 or a 1.

Syntax

%rc = $Web

Return codes

Code	Meaning
0	Not running a web request.
1	Running a web request.

Usage notes

• The $Web function is most useful for:
  • Preventing code that should only be run for a web request from running for 3270 (or other non-web) requests.
  • Ensuring that non-web, possibly 3270 specific code, is not run for web requests.
  • Under Model 204 7.8 and later, transactional daemon descendants of a web thread can also access the web API. However, $Web returns 0 on these threads. To check if the web API is available regardless of the thread type use $Web_Api.

  In the example below, the variable %DISTRICT is set from a form field when running a web request and from a screen field otherwise:

  if $web then %district = $web_form_parm('DISTRICT') else %district = %query:district end if

• $Web has several advantages over other techniques for determining whether a request is running a web request, such as checking $Web_Port or doing a $VIEW('IODEV'):
  • It is syntactically simple and easy to understand.
  • It works correctly even when a request is being debugged using JANUSDEBUG.
  • It works correctly and does not cause a "CONNECTION WAS LOST" user restart after the connection was closed either with a $Web_Done or by the browser. This can be especially useful if there is web-specific processing, like APSY navigation code, that happens after a $Web_Done.