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<span class="pageSubtitle"><section begin="desc" />Determine whether running a web request<section end="desc" /></span> | <span class="pageSubtitle"><section begin="desc" />Determine whether running a web request<section end="desc" /></span> | ||
$Web indicates whether the current processing is the result of a request to <var class="product">[[Janus Web Server]]</var>. | <var>$Web</var> indicates whether the current processing is the result of a request to <var class="product">[[Janus Web Server]]</var>. | ||
<var>$Web</var> takes no arguments and returns either a 0 or a 1. | |||
==Syntax== | ==Syntax== | ||
<p class="syntax"><section begin="syntax" /> % | <p class="syntax"><section begin="syntax" />%rc = $Web | ||
<section end="syntax" /></p> | <section end="syntax" /></p> | ||
===Return codes=== | |||
<table class="syntaxTable"> | <table class="syntaxTable"> | ||
<tr><th>Code</th> | <tr><th>Code</th> | ||
< | <th>Meaning</th></tr> | ||
<tr><th>0</th> | <tr><th>0</th> | ||
<td>Not running a web request.</td></tr> | <td>Not running a web request.</td></tr> | ||
<tr><th>1</th> | <tr><th>1</th> | ||
<td>Running a web request.</td></tr> | <td>Running a web request.</td></tr> | ||
</table> | </table> | ||
The $Web function is most useful for | ==Usage notes== | ||
<p class="code"> IF $Web THEN | <ul> | ||
<li>The <var>$Web</var> function is most useful for: | |||
<ul> | |||
<li>Preventing code that should only be run for a web request from running for 3270 (or other non-web) requests. | |||
<li>Ensuring that non-web, possibly 3270 specific code, is not run for web requests. | |||
</ul> | |||
In the example below, the variable %DISTRICT is set from a form field when running a web request and from a screen field otherwise: | |||
<p class="code">IF $Web THEN | |||
%DISTRICT = $Web_Form_Parm('DISTRICT') | |||
ELSE | |||
%DISTRICT = %QUERY:DISTRICT | |||
END IF | |||
</p> | </p> | ||
<li><var>$Web</var> has several advantages over other techniques for determining whether a request is running a web request, such as checking <var>[[$Web_Port]]</var> or doing a <code>$VIEW('IODEV')</code>: | |||
<ul> | |||
< | |||
<li>It is syntactically simple and easy to understand. | <li>It is syntactically simple and easy to understand. | ||
<li>It works correctly even when a request is being debugged using JANUSDEBUG. | <li>It works correctly even when a request is being debugged using JANUSDEBUG. | ||
<li>It works correctly and does not cause a "CONNECTION WAS LOST" user restart after the connection was closed either with a <var>$Web_Done</var> or by the browser. This can be especially useful if there is web-specific processing, like APSY navigation code, that happens after a <var>$Web_Done</var>. | <li>It works correctly and does not cause a "CONNECTION WAS LOST" user restart after the connection was closed either with a <var>[[$Web_Done]]</var> or by the browser. This can be especially useful if there is web-specific processing, like APSY navigation code, that happens after a <var>$Web_Done</var>. | ||
</ | </ul> | ||
[[Category:Janus Web Server $functions|$Web]] | [[Category:Janus Web Server $functions|$Web]] | ||
Revision as of 21:00, 16 June 2012
<section begin="desc" />Determine whether running a web request<section end="desc" />
$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
<section begin="syntax" />%rc = $Web <section end="syntax" />
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.
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.