$Web Expire: Difference between revisions
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<var>$Web_Expire</var> sets the expiration date and time for the Web Server response entity being returned by the application. Using <var>$Web_Expire</var>, you can control how long a browser caches an entity returned by your application. | |||
<var>$Web_Expire</var> requires one argument and returns a numeric status code. It is also [[Calling_Sirius_Mods_$functions|callable]]. | |||
==Syntax== | ==Syntax== | ||
<p class="syntax"><section begin="syntax" /> % | <p class="syntax"><section begin="syntax" />%rc = $Web_Expire( exp_time ) | ||
<section end="syntax" /></p> | <section end="syntax" /></p> | ||
===Syntax terms=== | |||
<table class="syntaxTable"> | <table class="syntaxTable"> | ||
<tr><th>exp_time</th> | <tr><th>exp_time</th> | ||
<td>A date/time expressed in seconds since 12 AM on January 1, 1900. You can use the $ | <td>A date/time expressed in seconds since 12 AM on January 1, 1900. You can use the <var>[[$Web_Datens]]</var> function to get the current date in this format, and manipulate it using standard <var class="product">User Language</var> expressions. | ||
</td></tr></table> | </td></tr></table> | ||
===Return codes=== | |||
<table class="syntaxTable"> | <table class="syntaxTable"> | ||
<tr><th>Code</th> | <tr><th>Code</th> | ||
< | <th>Meaning</th></tr> | ||
<tr><th>0</th> | <tr><th>0</th> | ||
<td>Completed successfully</td></tr> | <td>Completed successfully</td></tr> | ||
| Line 27: | Line 29: | ||
</table> | </table> | ||
==Examples== | |||
Use <var>$Web_Expire</var> to control how long a browser caches an entity returned by your application. | Use <var>$Web_Expire</var> to control how long a browser caches an entity returned by your application. | ||
<p class="code"> * Get current date in binary | <p class="code"> * Get current date in binary | ||
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%X = %X - (7*24-1)*60*60 | %X = %X - (7*24-1)*60*60 | ||
%RC = $Web_Expire( %X ) | %RC = $Web_Expire( %X ) | ||
</p> | </p> | ||
In the above example, <var>$Web_Expire</var> is called to set the expiration date for the response entity. A second <var>$Web_Expire</var> demonstrates that you can override the <var>$Web_Expire</var> value any time you wish. | In the above example, <var>$Web_Expire</var> is called to set the expiration date for the response entity. A second <var>$Web_Expire</var> demonstrates that you can override the <var>$Web_Expire</var> value any time you wish. | ||
See also [[$Web_Last_Modified]] | ==See also== | ||
<ul> | |||
<li><var>[[$Web_Last_Modified]]</var> | |||
<li>[[Janus Web Server application coding considerations#Understanding browser caching|"Understanding browser caching"]] | |||
</ul> | |||
[[Category:Janus Web Server $functions|$Web_Expire]] | [[Category:Janus Web Server $functions|$Web_Expire]] | ||
Revision as of 20:41, 15 June 2012
<section begin="desc" />Set expiration date/time of Web response<section end="desc" />
$Web_Expire sets the expiration date and time for the Web Server response entity being returned by the application. Using $Web_Expire, you can control how long a browser caches an entity returned by your application.
$Web_Expire requires one argument and returns a numeric status code. It is also callable.
Syntax
<section begin="syntax" />%rc = $Web_Expire( exp_time ) <section end="syntax" />
Syntax terms
| exp_time | A date/time expressed in seconds since 12 AM on January 1, 1900. You can use the $Web_Datens function to get the current date in this format, and manipulate it using standard User Language expressions. |
|---|
Return codes
| Code | Meaning |
|---|---|
| 0 | Completed successfully |
| -1 | Not a web thread |
| -4 | Invalid datetime value |
Examples
Use $Web_Expire to control how long a browser caches an entity returned by your application.
* Get current date in binary %X = $WEB_DATENS * Add one week to the current date %X = %X + 7*24*60*60 * Ensure browser doesn't cache returned data * longer than one week %RC = $Web_Expire( %X ) * Changed my mind, only cache URL for 1 hour. * The previous $Web_Expire call is forgotten. %X = %X - (7*24-1)*60*60 %RC = $Web_Expire( %X )
In the above example, $Web_Expire is called to set the expiration date for the response entity. A second $Web_Expire demonstrates that you can override the $Web_Expire value any time you wish.