Revision as of 03:44, 11 July 2013

The Caching Template Library is the template engine in glFusion. A template engine facilitates a manageable way to separate application logic and content from its presentation. This allows the programmer to focus specifically on the application and the template designer to focus on the presentation. It also allows site administrators to easily manipulate the look and feel of their site without having to know the application or become a programmer.

The benefits of the Caching Template Library are that it adds the following features to glFusion. These features benefit both the site administrator and the plugin developer.

• Compiles templates to PHP code for enhanced page load speeds.
• Adds logic processing to the templates.
• Ability to specify multiple locations to search for templates.

Compiles Templates to PHP code

One of the unique aspects about the Caching Template Library is template compiling. This means the Caching Template Library reads the template files and creates PHP scripts from them. Once they are created, they are executed from then on. Therefore there is no costly template file parsing for each request. Each template can take full advantage of the PHP compiler and cache solutions such as eAccelerator, ionCube mmCache or Zend Accelerator to name a few. Some anecdotal experience with performance testing can be found in this forum message.

Logic Processing

One design goal of the Caching Template Library is the separation of application logic and presentation logic. This means templates can certainly contain logic under the condition that it is for presentation only. Things such as checking if a specific variable is set and adjusting the display appropriately is a good example of presentation logic. Also, if you desire no logic in your templates you certainly can do so by boiling the content down to text and variables only.

Multiple Template Source Paths

There are many templates files within the glFusion system, plus all the template files that plugins use as well. If you want to change the look and feel of a site, generally only a small number of template files are actually modified. Having the ability to specify multiple templates paths allows you to have a base location for templates, and then simply copy the ones you wish to modify to an alternative location (usually the /custom folder in the same directory.) This reduces the overall disk storage needed on the server, and also provides a method to quickly see which templates have been modified. It also means that your modified template files will not be overwritten during a software upgrade.

Benefits

Benefits of the Caching Template Library include:

• It is extremely fast.
• It is efficient since the PHP parser does the dirty work.
• No template parsing overhead, only compiles once.
• It is smart about recompiling only the template files that have changed.
• The {!if}..{!else}..{!endif} constructs are passed to the PHP parser, so the {!if…} expression syntax can be as simple or as complex an evaluation as you like.
• It is possible to embed PHP code right in your template files, although this may not be needed (nor recommended) since the engine is so customizable.
• Built-in caching support.
• Multiple template sources.

Overall, the Caching Template Library brings a significant amount of value and features to a glFusion site.

Developer Information

VERSION CHECKS

You can tell that the caching template library is installed and what version of the library is running by checking if TEMPLATE_VERSION is defined using the PHP function defined().

TEMPLATE_OPTIONS

At the top of the file is an array of TEMPLATE_OPTIONS. These options are global options for all templates created by glFusion. They are:

'path_cache' (required)