flatpress/fp-includes/smarty-4.4.1/docs/programmers/plugins/plugins-resources.md

Resources

Resource plugins are meant as a generic way of providing template sources or PHP script components to Smarty. Some examples of resources: databases, LDAP, shared memory, sockets, and so on.

Custom Resources may be put in a file resource.foobarxyz.php within your $plugins_dir, or registered on runtime with registerResource(). In either case you will be able to access that resource by prepending its name to the template you're addressing: foobarxyz:yourtemplate.tpl.

If a Resource's templates should not be run through the Smarty compiler, the Custom Resource may extend Smarty_Resource_Uncompiled. The Resource Handler must then implement the function renderUncompiled(Smarty_Internal_Template $_template). $_template is a reference to the current template and contains all assigned variables which the implementor can access via $_template->smarty->getTemplateVars(). These Resources simply echo their rendered content to the output stream. The rendered output will be output-cached if the Smarty instance was configured accordingly. See libs/sysplugins/smarty_internal_resource_php.php for an example.

If the Resource's compiled templates should not be cached on disk, the Custom Resource may extend Smarty_Resource_Recompiled. These Resources are compiled every time they are accessed. This may be an expensive overhead. See libs/sysplugins/smarty_internal_resource_eval.php for an example.

<?php

/**
 * MySQL Resource
 *
 * Resource Implementation based on the Custom API to use
 * MySQL as the storage resource for Smarty's templates and configs.
 *
 * Table definition:
 * <pre>CREATE TABLE IF NOT EXISTS `templates` (
 *   `name` varchar(100) NOT NULL,
 *   `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 *   `source` text,
 *   PRIMARY KEY (`name`)
 * ) ENGINE=InnoDB DEFAULT CHARSET=utf8;</pre>
 *
 * Demo data:
 * <pre>INSERT INTO `templates` (`name`, `modified`, `source`) VALUES ('test.tpl', "2010-12-25 22:00:00", '{$x="hello world"}{$x}');</pre>
 *
 * @package Resource-examples
 * @author Rodney Rehm
 */
class Smarty_Resource_Mysql extends Smarty_Resource_Custom {
    // PDO instance
    protected $db;
    // prepared fetch() statement
    protected $fetch;
    // prepared fetchTimestamp() statement
    protected $mtime;

    public function __construct() {
        try {
            $this->db = new PDO("mysql:dbname=test;host=127.0.0.1", "smarty", "smarty");
        } catch (PDOException $e) {
            throw new SmartyException('Mysql Resource failed: ' . $e->getMessage());
        }
        $this->fetch = $this->db->prepare('SELECT modified, source FROM templates WHERE name = :name');
        $this->mtime = $this->db->prepare('SELECT modified FROM templates WHERE name = :name');
    }
    
    /**
     * Fetch a template and its modification time from database
     *
     * @param string $name template name
     * @param string $source template source
     * @param integer $mtime template modification timestamp (epoch)
     * @return void
     */
    protected function fetch($name, &$source, &$mtime)
    {
        $this->fetch->execute(array('name' => $name));
        $row = $this->fetch->fetch();
        $this->fetch->closeCursor();
        if ($row) {
            $source = $row['source'];
            $mtime = strtotime($row['modified']);
        } else {
            $source = null;
            $mtime = null;
        }
    }
    
    /**
     * Fetch a template's modification time from database
     *
     * @note implementing this method is optional. Only implement it if modification times can be accessed faster than loading the comple template source.
     * @param string $name template name
     * @return integer timestamp (epoch) the template was modified
     */
    protected function fetchTimestamp($name) {
        $this->mtime->execute(array('name' => $name));
        $mtime = $this->mtime->fetchColumn();
        $this->mtime->closeCursor();
        return strtotime($mtime);
    }
}


require_once 'libs/Smarty.class.php';
$smarty = new Smarty();
$smarty->registerResource('mysql', new Smarty_Resource_Mysql());

// using resource from php script
$smarty->display("mysql:index.tpl");
?>

And from within Smarty template:

{include file='mysql:extras/navigation.tpl'}

See also registerResource(), unregisterResource().