Smarty is a template engine for PHP. One of the unique aspects about Smarty is that it compiles the template files into native PHP scripts upon the first invocation. After that, it just executes the compiled PHP scripts. Therefore, there is no costly template file parsing for each request, and each template can take full advantage of PHP compiler cache solutions such as Zend Cache (http://www.zend.com) or PHP Accelerator (http://www.php-accelerator.co.uk). Some of Smarty's features: 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. You can make custom functions and custom variable modifiers, so the template language is extremely extensible. Configurable template delimiter tag syntax, so you can use {}, {{}}, <!--{}-->, etc. The if/elseif/else/endif constructs are passed to the PHP parser, so the {if ...} expression syntax can be as simple or as complex as you like. Unlimited nesting of sections, ifs, etc. allowed. 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 Arbitrary template sources Custom cache handling functions Plugin architecture Smarty compiles the templates into native PHP code on-the-fly. The actual PHP scripts that are generated are created implicitly, so theoretically you should never have to worry about touching these files, or even know of their existence. The exception to this is debugging Smarty template syntax errors, discussed later in this document. Smarty can cache the output of your generated templates. By default this is disabled. If you enable caching, Smarty will store a copy of the generated template output, and use this until the copy expires, regenerating a new one. The default cache expire time can be configured from the class. The exception to the rule is the insert tag. Anything generated by the insert tag is not cached, but run dynamically on every invocation, even within cached content. Any time you change a template, change values in config files or change the content that gets displayed in a template, you can turn on compile_check to regenerate the caches that are affected, or wait for the cache to expire to see the results of the changes. You clear caches manually by deleting files from the cache directory, programatically with clear_cache or clear_all_cache, or turn on $compile_check (or $force_compile). If you have caching enabled AND you have compile_check enabled, the cached file will regenerate if an involved template or config file has been modified, regardless of the cache expire time. This results in a slight performance hit since Smarty has to check the templates and config files for modification times. Therefore if you are not actively changing templates or config files, it is advisable to leave compile_check off. Enabling $force_compile will effectively disable caching, as the cache will get regerated on every invocation. Smarty requires a web server running PHP 4.0.6 or later. This installation guide makes the assumption that you are familiar with your web server setup, your PHP setup, and your operating system directory naming conventions. In these examples we use a Unix filesystem, so be sure you make the appropriate adjustments for your environment. To be sure the examples in this installation work, add "/php/includes" to your PHP include_path if it is not already there. Your include_path is usually set in your php.ini file. You can see your current include_path from phpinfo(), or you can use ini_get('include_path') from within your PHP script. First install the Smarty library files. These are the PHP files that you DO NOT edit. They are shared among all applications and they only get updated when you upgrade to a new version of Smarty. We highly recommend you do not edit the Smarty files. This makes upgrades much easier for you. You DO NOT need to edit these files to configure your applications! Use an instance of the Smarty class, which we'll get to in the sample setup below. This is a list of the required library files that come with Smarty: Smarty.class.php Smarty_Compiler.class.php Config_File.class.php debug.tpl /plugins/*.php (all of them!) You can either place these library files within your PHP include_path, or in any directory as long as you define that with the SMARTY_DIR constant. We'll show an example of both. Here is how you create an instance of Smarty in your PHP scripts: require('Smarty.class.php'); $smarty = new Smarty; If the library files are outside of your PHP include_path, you must define the absolute path with the SMARTY_DIR constant. SMARTY_DIR must end with a slash. Lets say we place our Smarty library files in "/usr/local/lib/php/Smarty/". define(SMARTY_DIR,'/usr/local/lib/php/Smarty/'); require(SMARTY_DIR.'Smarty.class.php'); $smarty = new Smarty; Now the library files are in place, it's time to setup the Smarty directories. For our installation example, we will be setting up the Smarty environment for a guest book application. We picked an application only for the purpose of a directory naming convention. You can use the same environment for any application, just replace "guestbook" with the name of your app. Be sure you know the location of your web server document root. In our example, the document root is "/web/www.domain.com/docs/". The Smarty directories are defined in the class variables $template_dir, $compile_dir, $config_dir and $cache_dir, which default to the values "templates", "templates_c", "configs" and "cache" respectively. In our example, we'll place all of these directories under "/web/www.domain.com/smarty/guestbook/". As a rule of thumb, none of these directories should be within the document root of your web server, and this is recommended to avoid any possible direct access. You may, for example, have config files with sensitive data. You will need as least one file under your document root, and that is the script accessed by the web browser. We will call our script "index.php", and place it in a subdirectory called "guestbook". It is convenient to setup the web server so that "index.php" can be identified as the default directory index, so if you access "http://www.domain.com/guestbook/", the index.php script will be executed without "index.php" in the URL. In Apache you can set this up by adding "index.php" onto the end of your DirectoryIndex setting (separate each entry with a space.) Lets take a look at the file structure so far: /php/includes/Smarty/Smarty.class.php /php/includes/Smarty/Smarty_Compiler.class.php /php/includes/Smarty/Config_File.class.php /php/includes/Smarty/debug.tpl /php/includes/Smarty/plugins/*.php /web/www.mydomain.com/smarty/guestbook/templates/ /web/www.mydomain.com/smarty/guestbook/templates_c/ /web/www.mydomain.com/smarty/guestbook/configs/ /web/www.mydomain.com/smarty/guestbook/cache/ /web/www.mydomain.com/docs/guestbook/index.php Smarty will need write access to the $compile_dir and $cache_dir, so be sure the web server user can write to them. This is usually user "nobody" and group "nobody". For OS X users, the default is user "web" and group "web". If you are using Apache, you can look in your httpd.conf file (usually in "/usr/local/apache/conf/") to see what user and group are being used. chown nobody:nobody /web/www.mydomain.com/smarty/templates_c/ chmod 770 /web/www.mydomain.com/smarty/templates_c/ chown nobody:nobody /web/www.mydomain.com/smarty/cache/ chmod 770 /web/www.mydomain.com/smarty/cache/ chmod 770 will be fairly tight security, it only allows user "nobody" and group "nobody" read/write access to the directories. If you would like to open up read access to anyone (mostly for your own convenience of viewing these files), you can use 775 instead. We need to create the index.tpl file that Smarty will load. This will be located in your $template_dir. {* Smarty *} Hello, {$name}! Now lets edit index.php. We'll create an instance of Smarty, assign a template variable and display the index.tpl file. define(SMARTY_DIR,'/usr/local/lib/php/Smarty/'); require(SMARTY_DIR.'Smarty.class.php'); $smarty = new Smarty; $smarty->template_dir = '/web/www.mydomain.com/smarty/guestbook/templates/'; $smarty->compile_dir = '/web/www.mydomain.com/smarty/guestbook/templates_c/'; $smarty->config_dir = '/web/www.mydomain.com/smarty/guestbook/configs/'; $smarty->cache_dir = '/web/www.mydomain.com/smarty/guestbook/cache/'; $smarty->assign('name','Ned'); $smarty->display('index.tpl'); In our example, we are setting absolute paths to all of the Smarty directories. If these directories are within your PHP include_path, then these settings are not necessary. However, it is more efficient and (in personal experience) less error-prone to set them to absolute paths. This ensures that Smarty is getting files from the directories you intended. Now load the index.php file from your web browser. You should see "Hello, Ned!" You have completed the basic setup for Smarty! This is a continuation of the basic installation, please read that first! A slightly more flexible way to setup Smarty is to extend the class and initialize your Smarty environment. So instead of repeatedly setting directory paths, assigning the same vars, etc., we can do that in one place. Lets create a new directory "/php/includes/guestbook/" and make a new file called "setup.php". // load Smarty library files define(SMARTY_DIR,'/usr/local/lib/php/Smarty/'); require(SMARTY_DIR.'Smarty.class.php'); // load application library files require('guestbook/guestbook.lib.php'); Smarty_GuestBook extends Smarty { function Smarty_GuestBook() { // Class Constructor. These automatically get set with each new instance. $this->template_dir = '/web/www.mydomain.com/smarty/guestbook/templates/'; $this->compile_dir = '/web/www.mydomain.com/smarty/guestbook/templates_c/'; $this->config_dir = '/web/www.mydomain.com/smarty/guestbook/configs/'; $this->cache_dir = '/web/www.mydomain.com/smarty/guestbook/cache/'; $this->caching = true; $this->assign('app_name','Guest Book'); } } In our example, we keep application libraries (not intended for direct browser access) in a separate directory outside of the document root. These files may contain sensitive data that we don't want any direct access to. We keep all library files for the guest book application under "/php/includes/guestbook/" and load them in the setup script, as you see in the above example. Now lets alter the index.php file to use setup.php: require('guestbook/setup.php'); $smarty = new Smarty_GuestBook; $smarty->assign('name','Ned'); $smarty->display('index.tpl'); Now you see it is quite simple to bring up an instance of Smarty, just use Smarty_GuestBook which automatically initializes everything for our application. This should be the full system path to the location of the Smarty class files. If this is not defined, then Smarty will attempt to determine the appropriate value automatically. If defined, the path must end with a slash. // set path to Smarty directory define("SMARTY_DIR","/usr/local/lib/php/Smarty/"); require_once(SMARTY_DIR."Smarty.class.php");