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 :

JotCache Install

Recommended install procedure :

1. Install JotCache Plugin from plg_system_jotcache_x.x.x_j15.zip via Administrator > Extensions > Install/Uninstall / Upload Package File.
2. Install JotCache Component from com_jotcache_x.x.x_j15.zip via Administrator > Extensions > Install/Uninstall / Upload Package File.
3. Open Plugin management : Administrator > Extensions > Plugin Manager / in Select type put 'system' and disable 'System - Cache' (when enabled) and open JotCache edit. Set plugin parameters as you like and save it with plugin enabled.
4. Reset the old cache content with Tools > Clean Cache select all items and press DELETE button.
5. When you are using System SEF plugin then JotCache plugin have to follow the System SEF plugin in the Joomla plugin list (adjust order in Extensions > Plugin Manager, the best position for JotCache is the last item in the list)
   

Uninstall

Recommended uninstall procedure :

1. Uninstall JotCache Component (when installed) : Administrator > Extensions > Install/Uninstall > Components check JotCache and press Uninstall button.
2. Uninstall JotCache Plugin : Administrator > Extensions > Install/Uninstall > Plugins check JotCache and press Uninstall button.

Now are all parts of JotCache removed from the application and database.

Upgrade from old version

Uninstall the component and the plugin as described above. Then install new version of JotCache as described in 'Installation'. 

Administration

JotCache Plugin

Because JotCache Plugin is advanced replacement of System - Cache it is necessary to disable system cache plugin in Administration > Extensions > Plugin Manager.

Open in Plugin Manager JotCache parameters :

and set their values to required operation mode :

1. Browser caching (Yes) - Web server is forcing the user browser to local cache of the sent content
2. Cache lifetime - Cached web page remains x minutes in page cache stored
3. Compress cached content (Yes) - In cached content are whitespaces removed and then the content is compressed (gzlib)
4. Mark caching (Yes) - Condition for displaying Set Mark in JotCache component (for presentation of front-end cache marking have to be both conditions met : Plugin Mark caching=Yes and Component Set Mark=On)

JotCache Component

JotCache Component is management layer over the basic JotCache Plugin functions :

• Overview of 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. This condition happens when you start caching of page content with JotCache and system page cache is not empty. Pages cached prior JotCache cache operation are not displayed in the JotCache Component overview. The similar condition occurs when system page cache is cleared outside JotCache Management (Administrator > Tools > Clean Cache).
• Filtering the list of cached pages according component name and view
• Deleting selected cached pages with possibility of individual or group (top check-box in the table header) checking of cached page contents for delete operation
  
• Marking cached content for administrator in the front-end with Set Mark button pressed - see Fast check of cache operation in front-end

Notes

1. Content Id reflects Id of specific component e.g. Content or Weblinks....
2. Created date presents first date/time of save of cached content via JotCache (this date/time is not refreshed with each repeating save of the cached page file)

With courtesy of Rivo Zängov (responsible also for Joomla 1.5.x Estonian translation) here it is possible to publish Estonian translation for JotLoader 2.2.1 Site and Admin (suitable for Joomla! 1.5.x). Language installation file you can find on JotLoader download page.