$Web Expire: Difference between revisions
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==Syntax== | ==Syntax== | ||
<p class="syntax"><span class="term">%rc</span> = $Web_Expire( exp_time ) | <p class="syntax"><span class="term">%rc</span> = <span class="literal">$Web_Expire</span>(<span class="term"> exp_time</span> ) | ||
</p> | </p> | ||
| Line 14: | Line 14: | ||
<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 <var>[[$ | <td>A date/time expressed in seconds since 12 AM on January 1, 1900. You can use the <var>[[$Web_Date, $Web_DateND, $Web_DateNM, and $Web_DateNS|$Web_DateNS]]</var> function to get the current date in this format, and manipulate it using standard <var class="product">SOUL</var> expressions. | ||
</td></tr></table> | </td></tr></table> | ||
===Return codes=== | ===Return codes=== | ||
<table class=" | <table class="thJustBold"> | ||
<tr><th>Code</th> | <tr class="head"><th>Code</th> | ||
<th>Meaning</th></tr> | <th>Meaning</th></tr> | ||
<tr><th>0</th> | <tr><th>0</th> | ||
<td>Completed successfully</td></tr> | <td>Completed successfully</td></tr> | ||
<tr><th>-1</th> | <tr><th>-1</th> | ||
<td>Not a web thread</td></tr> | <td>Not a web thread</td></tr> | ||
<tr><th>-4</th> | <tr><th>-4</th> | ||
<td>Invalid datetime value</td></tr> | <td>Invalid datetime value</td></tr> | ||
</table> | </table> | ||
==Examples== | ==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 | ||
%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 = $Web_Expire( %x ) | |||
* Changed my mind, only cache URL for 1 hour. | |||
* The previous <var>$Web_Expire</var> call is forgotten. | |||
%x = %x - (7*24-1)*60*60 | |||
%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 | 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>$Web_Expire</var> value any time you want. | ||
==See also== | ==See also== | ||
<ul> | <ul> | ||
<li><var>[[$Web_Last_Modified]]</var> | <li><var>[[$Web_Last_Modified]]</var> | ||
<li>[[Janus Web Server application coding considerations#Understanding browser caching| | <li>[[Janus Web Server application coding considerations#Understanding browser caching|Understanding browser caching]] | ||
</ul> | </ul> | ||
[[Category:Janus Web Server $functions|$Web_Expire]] | [[Category:Janus Web Server $functions|$Web_Expire]] | ||
Latest revision as of 20:25, 2 September 2014
Set expiration date/time of Web response
$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
%rc = $Web_Expire( exp_time )
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 SOUL 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 want.