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.
%rc = $Web
|0||Not running a web request.|
|1||Running a web request.|
- 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
- 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.