JotCache Usage

Purpose

JotCache is advanced solution for page caching in Joomla 1.5 search framework. JotCache consists from JotCache Plugin and optionally (but recommended) from JotCache Component. JotCache Plugin is extended replacement of standart System-Cache plugin with following enhancements :

• Fast-changing modules on the web page can be refreshed with actual content during each user access. You can mark the module positions with fast changeable content in site template and these position will be refreshed during each user access to related web page. The rest of page will be taken from cached content as usual by standart plugin System - Cache.
• Cached page content can be compressed before saving into the cache. JotCache plugin has option to compress (gzlib) cached pages before storing to the cache, therefore the web access to cached content is accelerated. Compressing function covers static (page) as well as dynamic module content.
• Possibility to clear the cache only for selected pages. With accompanied JotCache Component here it is possible to see the actual cached pages linked to used component and view. You can delete the selected cached pages (marked in component list view) leaving the rest of cached pages intact.
• Fast check of cache operation on production site front-end without disturbing other users. For easy overview of cache mechanism on front-end pages administrator can mark his/her browser access with specific cookie allowing to display marked content (in front-end) solely to administrator.

Module positions excluded from page caching

In the Joomla 1.5 CMS framework each module is placed to template's specific position (see Administrator > Extensions > Module Manager / column Position. Graphical presentation see Administrator > Extensions > Template Manager, click on used template name and click toolbar button Preview). In the template each module position is tagged with tag :

<jdoc:include type="modules" name="xxx" ... />

where xxx is position name.

To exclude specific module position from page caching here it is necessary to mark this position in template source (index.php) with HTML comment tags - see example :

<td>
   <!-- jot user2 s style="xhtml" --><jdoc:include type="modules" name=user2" style="xhtml" /><!-- jot user2 e -->
</td>

Text in the marking tags is separated with exactly one (1) space starting with word jotfollowed by name_of_position jot_flag params

where

name_of_position - name of position as it is used in jdoc tag
jot_flag - 's' for start marking, 'e' for end marking
params - any kinds of jdoc parameters separated with space character

Mark in the template only module positions which you like to steady refresh. When page is cached then mark tags are stored with cached content. During cached content recall the marked positions are replaced with newest modules content.

Fast check of cache operation in front-end

For proper marking of cached content you need to have installed not only plugin but also the JotCache component. In the JotCache Plugin parameters it is necessary to set Mark Caching to Yes :

and in the JotCache component click on Set Mark button :

With Set Mark button here it is sent marking cookie to your browser and then you can see marked page title (with three @@@) when page is comming from cache :

and steady refreshed module positions are marked with dashed red outline :

Cache management

With JotCache Component you have possibility to look into one-to-one relation between cached page file (with hashed name e.g. 8d2146c2a4b1b3c9d65bac698c9115a5.php) and its original resource (component name, view, content id). This one-to-one relation is stored in database and when it is necessary to synchronize page cache in the file system with database overview simply press Refresh button on component's toolbar.

With filtering and checking here is easy to select cached page contents for delete operation :