<?php



//

// Open Web Analytics - An Open Source Web Analytics Framework

//

// Copyright 2006 Peter Adams. All rights reserved.

//

// Licensed under GPL v2.0 http://www.gnu.org/copyleft/gpl.html

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//

// $Id$

//



/**

 * Template

 * 

 * @author      Peter Adams <peter@openwebanalytics.com>

 * @copyright   Copyright &copy; 2006 Peter Adams <peter@openwebanalytics.com>

 * @license     http://www.gnu.org/copyleft/gpl.html GPL v2.0

 * @category    owa

 * @package     owa

 * @version		$Revision$	      

 * @since		owa 1.0.0

 */

class Template {



	/**

	 * Template files directory

	 *

	 * @var string

	 */

	var $template_dir;

	

	/**

	 * Template Variables

	 *

	 * @var array

	 */

    var $vars = array();

    

    /**

     * Template file

     *

     * @var string

     */

    var $file;



    /**

     * Constructor

     *

     * @access public 

     */

    function Template() {

        

        return;

    }

	

    /**

     * Set the template file

     *

     * @param string $file

     */

	function set_template($file = null) {

        $this->file = $this->template_dir.$file;

        return;

    }



	/**

	 * Set a template variable

	 *

	 * @param string $name

	 * @param unknown_value $value

	 * @access public

	 */

    function set($name, $value) {

    

    	if (is_object($value)) {

    		$class  = 'Template';

    		if ($value instanceof $this) {

    			$value = $value->fetch();

    		}

    	} 

    

        $this->vars[$name] =  $value;

        return;

    }



    /**

     * Open, parse, and return the template file.

     *

     * @param string $file

     * @return string $contents

     * @access public

     */

    function fetch($file = null) {

        if(!$file):

			 $file = $this->file;

		else:

			$file = $this->template_dir.$file;

		endif;



        extract($this->vars);          // Extract the vars to local namespace

        ob_start();                    // Start output buffering

        include($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 $cache_id string unique cache identifier

     * @param $expire int number of seconds the cache will live

     */

    function CachedTemplate($cache_id = null, $expire = 900) {

        $this->Template();

        $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.

     */

    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

     */

    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;

        }

    }

}



?>