View source for $Web Sub

{{DISPLAYTITLE:$Web_Sub}}
<span class="pageSubtitle">Set delimiter for procedure text substitution</span>

<var>$Web_Sub</var> sets the delimiter for designating text to be symbolically substituted when text is sent to the client from within <var class="product">Model 204</var> procedures.

<var>$Web_Sub</var> is a [[Calling Sirius Mods $functions|callable]] $function, and it takes a single string argument and returns a status code.

==Syntax==
<p class="syntax"><span class="term">%rc</span> = <span class="literal">$Web_Sub</span>(<span class="term"> delimiter</span> )
</p>

<table class="syntaxTable">
<tr><th>%rc</th>
<td>A numeric [[#Status codes|status code]].
<tr><th>delimiter</th>
<td>A 1- to 3-character string, or a null string.
</td></tr>
</table>

===Status codes===
<table>
<tr><th>Code</th>
<th>Meaning</th></tr>
<tr><th>0</th>
<td>Substitution delimiter successfully set.</td></tr>
<tr><th>-1</th>
<td>Invalid call, not a Web thread</td></tr>
<tr><th>-4</th>
<td>Invalid argument (more than 3 characters long)</td></tr>
</table>

==Usage notes==
<ul>
<li>If not null, <var class="term">delimiter</var> is used to identify the text strings in a <var class="product">Model 204</var> procedure that should be symbolically substituted before presentation to the client. Strings that begin with the given delimiter and end with an exclamation mark ( ! ) will be matched against the Global Variable Table (GTBL), and the value of any such global variables will be substituted for the string. 

<li>Symbolic substitution performed by the <var>$Web_Sub</var> setting only affects lines sent to the client by <var>$Web_ProcSend</var> or by the SEND subcommand in the ON rule chosen for the URL. 

<li>Until <var>$Web_Sub</var> is called, <var class="product">[[Janus Web Server]]</var> does not perform any substitution of strings into procedures sent to the client. Setting <var>$Web_Sub</var> to null also turns off substitution. 

<li>As with all $WEB_ functions, <var>$Web_Sub</var> can be invoked by CMD processing, which is specified either in the ON rule for the URL or in the JANUS DEFINE ... WEB command for the port. Note that <var>$Web_Sub</var> can only affect procedures referenced in SEND rules if <var>$Web_Sub</var> is called due to the JANUS DEFINE ... WEB command.
</ul>

==Examples==
<p class="code"><HTML>
<p>Greetings from @LOCATION!.
<p>Having a @QUALITY! time.
<p>Wish you were @WISHLOC!.
</HTML>
 
 . . .
 
%X = $SETG('LOCATION','Springfield')
%X = $SETG('QUALITY','nice')
%X = $SETG('WISHLOC','rich')
 
%X = $Web_Sub('@')
%X = $Web_ProcSend( 'HTMLFILE', 'GREETING' )
</p>
<p>
In the example above, an at sign (<tt>@</tt>) is used as the substitution indicator for global names in procedure text. The client would see: </p>
<p class="code">Greetings from Springfield.
Having a nice time.
Wish you were rich.
</p>

[[Category:Janus Web Server $functions|$Web_Sub]]