Template engine (web)

A (web) template engine is software that is designed to process web templates and "content information" to produce output web documents. It runs in the context of a template system.

pecific types of template engines

"Template engine" is ordinarily included as a part of a web template system or application framework, and may be used also as preprocessor, filter, or template processor. Currently, template processing software is most frequently used in the context of development for the web.

XSLT is a template processing model designed by W3C. It is designed primarily for transformations on XML data (into web documents or other output).

Programming languages such as Perl, Ruby, C, and Java support template processing either natively, or through add-on libraries and modules. JavaServer Pages (JSP), PHP, and Active Server Pages (ASP with VBScript, JScript or other languages) are examples, themselves, of "web template engines".

Typical Features

Template engines typically include features common to most high-level programming languages, with an emphasis on features for processing plain text.

Such features include:
*variables and functions
*text replacement
*file inclusion (or transclusion)
*conditional evaluation and loops

A web template example

The accompanying illustration depicts a simplified processing model for a typical web template engine. The template engine produces a web page by processing the web template source file along with data from a relational database. The template engine replaces variables with specific values. In the illustration, substitution of $X by the database content (in page 01 "Mother", on page 02 "World").

A web template might look like this:

Hello {$X}

With additional template source code ...

templateAssign ('X', 'World');

... or, when specifying the relational database context:

$data [01] ='Mother'; $data [02] ='World';templateAssign('X', $data [$i] );

Benefits of using template engines

* encourages organization of source code into operationally-distinct layers (see e.g., MVC)
* enhances productivity by reducing unnecessary reproduction of effort
* enhances teamwork by allowing separation of work based on skill-set (e.g., artistic vs. technical)

= Comparison of template engines =

The following table lists the various template engines discussed on Wikipedia and a brief rundown of their features. The content here is a work-in-progress.

ee also

* Template processor
* Layout engine
*
* Macro preprocessor
* Preprocessor
* Smarty (PHP: Template engine)
* Mytemplate (PHP: MyTemplate engine)
* vlibTemplate (PHP: Template engine)
* Jasper framework
* Virtual machine
* Bytecode

External links

Other template engines on template systems:
* [http://2006.rmll.info/conf_423 Acceleo - MDA template based Code generator based on Eclipse and EMF]
* [http://sourceforge.net/projects/blitz-templates Blitz templates (PHP-module, written in C, very fast, OO, MVC)] , [http://alexeyrybak.com/blitz/blitz_en.html documentation] . Probably the fastest engine for PHP, [http://alexeyrybak.com/blitz/lebowski-bench-big.gifsee benchmarks] , [http://www.kmit.sk/~smok/#mystuff Simple Blitz tutorial]
* [http://beilpuz.get-mike.de Beilpuz (PHP 5)]
* [http://ctpp.havoc.ru/en/ CT++ Crossplatform C/C++/Perl and PHP Template engine]
* [http://code.divineaspirations.net/chip Chip]
* [http://www.typea.net/software/contemplate/ Contemplate]
* [http://dwoo.org/ Dwoo (PHP 5, mostly Smarty compatible)]
* [http://www.cs.usfca.edu/~parrt/papers/mvc.templates.pdf Enforcing Strict Model-View Separation in Template Engines]
* [http://evoque.gizmojo.org Evoque Templating] - sandbox-able, lightweight, [http://evoque.gizmojo.org/benchmark/ fast] text templating for Python, with automatic Cross-site scripting protection
* [http://rubyforge.org/projects/galena/ Galena: Another Ruby Template Engine]
* [http://www.liquidmarkup.org/ Liquid Ruby template engine]
* [http://xtargets.com/cms/Tutorials/Matlab-Programming/MTemplate-Matlab-Code-Generation-and-Text-Templating.html Matlab template engine]
* [http://www.freemarker.org FreeMarker]
* [http://pear.php.net/package/HTML_Template_IT HTML_Template_IT]
* [http://outline.mindplay.dk Outline] - PHP template engine, borrows from Smarty and PHP syntax - very small footprint
* [http://trac.php-tools.net/patTemplate/ patTemplate]
* [http://sourceforge.net/projects/php-templates php_templates (PHP-module, written in C, very fast)]
* [http://smarttemplate.sourceforge.net/ SmartTemplate]
* [http://smarty.php.net/ Smarty]
* [http://www.startonweb.com/ startonweb]
* [http://www.stringtemplate.org/ StringTemplate]
* [http://www.template-toolkit.org/ Template::Toolkit]
* [http://search.cpan.org/~rhandom/Template-Alloy-1.008/ Template::Alloy]
* [http://templatelite.sourceforge.net/ Template Lite]
* [http://www.tinybutstrong.com/ TinyButStrong]
* [http://vlib.clausvb.de/ vLIB]
* [http://www.greaterscope.net/projects/Vemplator Vemplator]

Template engine usage:
* [http://g-rossolini.developpez.com/comparatifs/php/templates/ How to use the main PHP template engines, and a comparison chart (French)]