Template.php

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

define('DS', DIRECTORY_SEPARATOR, TRUE);

class Template {
	
	public $template_dir;
	public $template_cache;
	public $template_expiry;
	public $template_extension;

	public function __construct()
	{
		// codeigniter instance
		$this->ci =& get_instance();
		// load setting model
		$this->ci->load->model('setting');
		// codeigniter constent (look ~/index.php)
		$this->template_theme	  = $this->ci->setting->get('site_theme');
		$this->template_dir       = APPPATH.DS.'views'.DS.$this->template_theme.DS;
		$this->template_cache     = APPPATH.DS.'cache'.DS;
		$this->template_expiry    = 3600*24; // default to 24 hours
		$this->template_extension = 'tpl';
	}

	public function load($file){
		$template = new templateHandler($file, $this);
		return $template;
	}
}


class TemplateHandler {
	public $file;
	public $content;
	public $output;
	public $app;
	public $src,$cachefile,$cachecontent,$time;

	public function __construct($file,$app){
		$this->file = $file;
		$this->app  = $app;
		$this->load();

		// codeigniter instance
		$this->ci =& get_instance();
	}
	public function load(){
		$src             = $this->app->template_dir.$this->file.".".$this->app->template_extension;
		$this->cachefile = $this->app->template_cache . md5($this->file) .".".$this->app->template_extension;
		$inc             = file_exists($src);

		if(!$inc)
		{
			// use codeigniter logging system instead
			$msg = sprintf("Template file [%s] doesn't exist", $this->file);
			log_message('debug', $msg);
		}
		else
		{
			$source             = fopen($src,'r');
			$file               = @fread($source,filesize($src));
			fclose($source);
			$cache              = fopen($this->cachefile,'w+');
			$this->cachecontent = @fread($cache,filesize($this->cachefile));
			fclose($cache);
			$this->content      = $file;
			$this->cachecontent = $file;
			$this->output       = $file;
			$this->output       = preg_replace("/\{(.*)\}/siU","<?php echo \\1; ?>",$this->output);
			$this->output       = preg_replace_callback("/\<(for|while|do|if|elseif|foreach)(\s+)\((.+)\)(\s*)\>/siU",array($this,"parse_cond_template"),$this->output);
			$this->output       = str_replace("</end>","<?php } ?>",$this->output);
		}
		$this->should_update = ((file_exists($this->cachefile) && time() - (($this->app->template_expiry * 60 * 60) >= filemtime($this->cachefile))  && $this->output!=$this->cachecontent)  || !file_exists($this->cachefile));
		$this->time          = file_exists($this->cachefile) && !$this->should_update?filemtime($this->cachefile):time();
	}
	public function assign($var,$content){
		$this->vars[$var] = $content;
		$this->output     = str_replace($var,"\$this->vars[\"$var\"]",$this->output);
		if(is_array($content)){
			$this->assign_array($var,$content);
		}
	}
	private function get_tree($tree){
		if($tree == "") return "";
		$explode = explode(".",$tree);
		$return  = "";
		foreach($explode as $key){
			if(preg_match("/^[a-zA-Z0-9_]+$/siU",$key)){
				$return .= "[\"$key\"]";
			}elseif($key!=""){
				console::log("Invalid array key used in Template::assign \"$key\"","TEMPLATE");
			}
		}
		return $return;
	}
	public function assign_array($var,$array,$tree=""){
		foreach($array as $key=>$value){
			$current = $tree.".".$key;
			$this->output = str_replace($var.$current,"\$this->vars[\"$var\"]".$this->get_tree($current)."",$this->output);
			if(is_array($value)) $this->assign_array($var,$value,$current);
		}
	}
	public function save(){
		if($this->should_update){
			$source = fopen($this->cachefile,'w+');
			fwrite($source,$this->output);
			fclose($source);
		}
	}
	public function get_template($url){
		$template = new TemplateHandler($url,$this->app);
		foreach($this->vars as $k=>$v){
			$template->assign($k,$v);
		}
		return $template->render(true);
	}
	public function getVariable($key){
		return $this->vars[$key];
	}
	private function parse_include_template($input){
		eval("\$return = \$this->get_template({$input[1]});");
		return $return;
	}
	private function parse_cond_template($input){
		return "<?php ".$input[1]."(".$input[3]."){ ?>";
	}
	private function parse_template(){
		$this->output = preg_replace_callback("/\<include\s+file=\"(.+)\"\s*\/\>/siU",array($this,"parse_include_template"),$this->output);
		$this->output = preg_replace("/lang_([a-zA-Z0-9_]+)/","lang(\"\\1\")",$this->output);
	}
	public function render($return=FALSE){
		$this->parse_template();
		$template = $this;
		$this->save();

		if($return)
		{
			return $this->output;
		}
		else
		{	
			ob_start();
			include_once($this->cachefile);
			$output = ob_get_clean();
			// append to global output
			$this->ci->output->append_output($output);
		}
	}
}