Помимо механизма шаблонов

Исходный код класса шаблона

И, наконец, класс Template.

 <?php    /**    * Copyright (c) 2003 Brian E. Lozier ([email protected])    *    * set_vars() method contributed by Ricardo Garcia (Thanks!)    *    * Permission is hereby granted, free of charge, to any person obtaining a copy    * of this software and associated documentation files (the "Software"), to    * deal in the Software without restriction, including without limitation the    * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or    * sell copies of the Software, and to permit persons to whom the Software is    * furnished to do so, subject to the following conditions:    *    * The above copyright notice and this permission notice shall be included in    * all copies or substantial portions of the Software.    *    * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR    * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,    * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE    * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER    * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING    * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS    * IN THE SOFTWARE.    */       class Template {       var $vars; /// Holds all the template variables       var $path; /// Path to the templates          /**        * Constructor        *        * @param string $path the path to the templates        *        * @return void        */       function Template($path = null) {           $this->path = $path;           $this->vars = array();       }          /**        * Set the path to the template files.        *        * @param string $path path to template files        *        * @return void        */       function set_path($path) {           $this->path = $path;       }          /**        * Set a template variable.        *        * @param string $name name of the variable to set        * @param mixed $value the value of the variable        *        * @return void        */       function set($name, $value) {           $this->vars[$name] = $value;       }          /**        * Set a bunch of variables at once using an associative array.        *        * @param array $vars array of vars to set        * @param bool $clear whether to completely overwrite the existing vars        *        * @return void        */       function set_vars($vars, $clear = false) {           if($clear) {               $this->vars = $vars;           }           else {               if(is_array($vars)) $this->vars = array_merge($this->vars, $vars);           }       }          /**        * Open, parse, and return the template file.        *        * @param string string the template file name        *        * @return string        */       function fetch($file) {           extract($this->vars);          // Extract the vars to local namespace           ob_start();                    // Start output buffering           include($this->path . $file);  // Include the file           $contents = ob_get_contents(); // Get the contents of the buffer           ob_end_clean();                // End buffering and discard           return $contents;              // Return the contents       }    }       /**    * An extension to Template that provides automatic caching of    * template contents.    */    class CachedTemplate extends Template {       var $cache_id;       var $expire;       var $cached;          /**        * Constructor.        *        * @param string $path path to template files        * @param string $cache_id unique cache identifier        * @param int $expire number of seconds the cache will live        *        * @return void        */       function CachedTemplate($path, $cache_id = null, $expire = 900) {           $this->Template($path);           $this->cache_id = $cache_id ? 'cache/' . md5($cache_id) : $cache_id;           $this->expire   = $expire;       }          /**        * Test to see whether the currently loaded cache_id has a valid        * corrosponding cache file.        *        * @return bool        */       function is_cached() {           if($this->cached) return true;              // Passed a cache_id?           if(!$this->cache_id) return false;              // Cache file exists?           if(!file_exists($this->cache_id)) return false;              // Can get the time of the file?           if(!($mtime = filemtime($this->cache_id))) return false;              // Cache expired?           if(($mtime + $this->expire) < time()) {               @unlink($this->cache_id);               return false;           }           else {               /**                * Cache the results of this is_cached() call.  Why?  So                * we don't have to double the overhead for each template.                * If we didn't cache, it would be hitting the file system                * twice as much (file_exists() & filemtime() [twice each]).                */               $this->cached = true;               return true;           }       }          /**        * This function returns a cached copy of a template (if it exists),        * otherwise, it parses it as normal and caches the content.        *        * @param $file string the template file        *        * @return string        */       function fetch_cache($file) {           if($this->is_cached()) {               $fp = @fopen($this->cache_id, 'r');               $contents = fread($fp, filesize($this->cache_id));               fclose($fp);               return $contents;           }           else {               $contents = $this->fetch($file);                  // Write the cache               if($fp = @fopen($this->cache_id, 'w')) {                   fwrite($fp, $contents);                   fclose($fp);               }               else {                   die('Unable to write cache.');               }                  return $contents;           }       }    }    ?> 

Еще одна важная вещь, которую стоит отметить в представленном здесь решении, это то, что мы передаем имя файла шаблона в вызов метода fetch() . Это может быть полезно, если вы хотите повторно использовать объекты шаблона без необходимости re-set() всех переменных.

И помните: смысл движков шаблонов должен заключаться в том, чтобы отделить вашу бизнес-логику от логики представления, а не отделять ваш PHP-код от вашего HTML-кода.