What is Smarty?

Smarty is a template engine for PHP. More specifically, it facilitates a manageable way to separate application logic and content from its presentation. This is best described in a situation where the application programmer and the template designer play different roles, or in most cases are not the same person.

Crash Course

For those of you who have used PHP template engines, the basic concepts of Smarty should look quite familiar. In your PHP application you assign variables for use in the template, then you display it.
index.php

include('Smarty.class.php');
// create object
$smarty = new Smarty;
// assign some content. This would typically come from
// a database or other source, but we'll use static
// values for the purpose of this example.
$smarty->assign('name', 'george smith');
$smarty->assign('address', '45th & Harris');
// display it
$smarty->display('index.tpl');

The template file then contains the output interspersed with tags that Smarty replaces with assigned content.
index.tpl

Name: {$name}
Address: {$address}
Output

html
head
titleUser Info
/head
body
User Information:

Name: george smith

Address: 45th & Harris

/body
/html

As you can see, Smarty cleanly separates your presentation elements (HTML, CSS, etc.) from your application code. However, it does not necessarily separate logic entirely from your templates. With respect to Smarty's design principles, so long as the logic in the templates is for presentation only, it is permissible to use it. For instance, looping over table row colors or including one template from another would be considered presentation logic. This is something the application should not need to accomodate (it just supplies an array of data.) The idea is to keep the template designer role and application programming role separated. You should be able to completely tear down the templates and rebuild them without touching the code base, all while retaining full control of the presentation. With this comes an important point: there is nothing stopping you from putting application logic in the template. Smarty has more than enough power to let you shoot yourself in the foot, so you must have some self discipline in this respect. Don't worry though, with a little bit of practice it becomes quite self-evident what logic belongs where.


Quick install

Windows users may want to follow this install guide

This is a simple guide to get Smarty setup and running quickly. The online
documentation includes a very thorough explanation of a Smarty installation.
This guide is meant to be a quick and painless way of getting Smarty working,
and nothing more. The guide assumes you are familiar with the UNIX system
environment. Windows users will need to make adjustments where necessary.

INSTALL SMARTY LIBRARY FILES

Copy the Smarty library files to your system. In our example, we place them in
/usr/local/lib/php/Smarty/

$> cd YOUR_DOWNLOAD_DIRECTORY
$> gtar -zxvf Smarty-2.6.7.tar.gz
$> mkdir /usr/local/lib/php/Smarty
$> cp -r Smarty-2.6.7/libs/* /usr/local/lib/php/Smarty

You should now have the following file structure:

/usr/local/lib/php/Smarty/
Config_File.class.php
debug.tpl
internals/
plugins/
Smarty.class.php
Smarty_Compiler.class.php


SETUP SMARTY DIRECTORIES

You will need four directories setup for Smarty to work. These files are for
templates, compiled templates, cached templates and config files. You may or
may not use caching or config files, but it is a good idea to set them up
anyways. It is also recommended to place them outside of the web server
document root. The web server PHP user will need write access to the cache and
compile directories as well.

In our example, the document root is /web/www.domain.com/docs and the
web server username is "nobody". We will keep our Smarty files under
/web/www.domain.com/smarty

$> cd /web/www.domain.com
$> mkdir smarty
$> mkdir smarty/templates
$> mkdir smarty/templates_c
$> mkdir smarty/cache
$> mkdir smarty/configs
$> chown nobody:nobody smarty/templates_c
$> chown nobody:nobody smarty/cache
$> chmod 775 smarty/templates_c
$> chmod 775 smarty/cache