Cached content for different browsers

Q : There are some features in my site which controls the layout and other features based on the client browser type but with cache activated they doesn't work. It could be very useful if JotCache plugin could save separated cached versions for each browser type.

A : When your application recognize user browser type you need to express your browser category in URL (e.g. browser=3 and so on). You can have as many browser group as you like. With this implementation you can use JotCache without any change for different browser presentations.

Cached content output is not correct (loosing some styling and/or some parts of the page)

Q : After switching JotCache Enabled ON in Plugin Manager the cached content output is not displayed correct.

A : JotCache cached output have to stored in page cache with all necessary redirects and rewrites. Other plugins in system group can make this type of processing therefore it is necessary to move JotCache plugin as last item in Plugin Manager order list (take care that you have JotCache as last item also after plugin enabling in Plugin Manager list).

Explaining JotCache caching processes

Q : Having problems with proper JotCache implementation on the website. What are basic principles which is needed to take in care ?

A : At first here it is necessary to have good knowledge about Joomla 1.5 system caching – best overview gives this article. JotCache is built on top of Joomla system caching (global caching have to be set on, system Cache plugin have to be set off – details in JotCache Help).

JotCache is page cache type (fastest for entire page delivery). Caching is done in the following manner :

  1. in the cache storage are cached all page modules (without jot tags) and component output (when not excluded in JotCache Component)
  2. passive modules (without user input) which have output internally modified (e.g. different counters as "Active users") have to be taken out of caching processing by means of special jot tags
  3. active modules with user input (e.g. Login) are during active submit not taken from the cache but they are direct processed (note : when Login is located on homepage and homepage is stored in cache then Login starts without any influence of cached content). Some active modules with more step processing (e.g. Polls) can be also necessary to remove from page caching by means of special jot tags.
  4. page caching IS NOT ACTIVE for registred users, excluded components/views/selected pages and jot tagged modules

Long processing when Cache Management is opened

Q : Recently, I am not able to access the JotCache component; it just loads forever.

A : You have most probably too much cached items expired in database and/or file system. JotCache is not loading forever but it is removing old issues from the cache (during opening Cache Management in JotCache component). You can take following actions :

  • in Administer/Tools use Clean / Purge Cache (cleaning cached items in the file system)
  • use autoclean of JotCache plugin with lower setting 2-5 (and autoclean log to see the range of autocleaning process)
  • because of additional time used for autoclean during frontend access only cache files are deleted and database copies are not removed. The database copies are removed when you open JotCache component Cache Management. To regulary remove expired database items automatically you can use cron job with the php file which you can find on download page.

Problem with RSS and ATOM

Q : When enabling JotCache plugin, the RSS page is not displaying only the home page is shown. After disabling Jotcache the RSS is working normaly.

A : After some analysis it was found that problem is caused by SH404sef also in the case when JotCache was located as last system plugin in Plugin Manager. Using Ninja RSS solution allows JotCache, sh404SEF and Ninja RSS working alltogether satisfactory.

JotCache plugin in versions 1.2.2 and 1.3.0 have problem with proper feeds and PDF presentation in frontend when using SEF and 'Add suffix to URLs' in Joomla global configuration is set. Reason for these obstacles are described in following statements (Joomla! General Development message and Joom::Gallery FAQ). To overcome this limitation use JotCache plugin version 1.3.1(+).

Some javascript code is not working properly

Q : After enabling JotCache some javascript code is not working properly.

A : Look closer to the conditions how is javascript loaded :

1. Mostly this obstacle appears when part or entire js code is embedded into HTML page and it is dynamic changed in time. In such cases it is recommended to remove embedded js code from HTML and leave it loaded as separate *.js file.

2. Other behavior was found when using  JCH Optimize along JotCache and part of embedded js code was not working. It was recognized that // comment style in js code caused problem and it was necessary to replace it with /* */ comments.

Using Google translator with JotCache

Q : I'm using a module to translate my site using Google translator into other languages. I use a cookie to detect if user is using a translated language and then i call the translator funcion. Problem is that if one user translates the site into german, for example the page is being cached and then when other user opens the site he gets the translated version.

A : When you are using dynamic language translations then you need to express user current language in URL query string. Language code used have to be conform with standart locale usage in Joomla 1.5 (e.g.  using lang=de in URL http://www.somedomain.com/joomla/index.php?lang=de). Described usage is full compatible with Joom!Fish component. With this implementation you can use JotCache without any change for different language variants.

Using SH404sef with JotCache

Q : When using JotCache with SH404sef, homepage gets a 404 error.

A : SH404sef can be used with JotCache but the JotCache have to be located as last item in the list of system plugins (it is necessary in Administrator/Plugin Manager to move JotCache behind SH404sef plugins).

Using Virtuemart with JotCache

Q : When using JotCache with Viruemart what is necessary to take care of.

A : JotCache was used sucessfully with Virtuemart when some adjustments were made :

  • Exclusion of some pages in JotCache component for com_virtuemart : page=shop.cart,page=checkout.index
  • Virtuemart must have all instances of "$mosConfig_live_site" replaced with "JURI :: base()" when used with sh404SEF and JotCache (this statement is depreciated now - it was valid in the time when VirtueMart longer time was coded for J1.0 and used in J1.5 environment.)
  • When other plugins for optimization are used e.g. JCH Optimise , which are stripping out the HTML comment tag, then comment stripping have to be switched off.

Make sure to clear all site and browser caches and enable the debug cookie (mark) if things don't look right!