MVC是模型(Model)、视图(View)和控制(Controller)的缩写，PHP中采用MVC模式的目的是实现Web系统的职能分工，通俗的说就是把业务逻辑处理从用户界面视图中分离出来。

使Web系统的开发与维护更加方便，从而有效的节省人力物力，受到了越来越多企业的青眯。

模板引擎是MVC模式建立过程的重要方法，开发者可以设计一套赋予含义的标签，通过技术解析处理有效的把数据逻辑处理从界面模板中提取出来，通过解读标签的含义把控制权提交给相应业务逻辑处理程序，从而获取到需要的数据，以模板设计的形式展现出来，使设计人员能把精力更多放在表现形式上。下面是我对模板引擎的认识与设计方法：

说的好听些叫模板引擎，实际就是解读模板数据的过程（个人观点^^）。通过我对建站方面的思考认识，网站在展现形式上无非归纳为单条和多条两种形式，那么我们可以设定两种对应标签（如data、list）来处理这两种情况，关键点在于解决两种标签的多层相互嵌套问题，基本适合实现80%界面形式。

解读模板的方法有多种，常用的包括字符串处理（解决嵌套稍麻烦）、正则表达式。在这里我选用的正则表达式，下面是我的处理方法（本文仅提供思路和参考代码，可能不能直接使用）。

模板文件解析类：

 
<?php 
/* 
* class: 模板解析类 
* author: 51JS.COM-ZMM 
* date: 2011.3.1 
* email: [email protected] 
* blog: http://www.cnblogs.com/cnzmm/ 
*/ 
class Template { 
public $html, $vars, $bTag, $eTag; 
public $bFlag='{', $eFlag='}', $pfix='zmm:'; 
private $folder, $file; 
function __construct($vars=array()) { 
!empty($vars) && $this->vars = $vars; 
!empty($GLOBALS['cfg_tag_prefix']) && 
$this->pfix = $GLOBALS['cfg_tag_prefix'].':'; 
$this->bTag = $this->bFlag.$this->pfix; 
$this->eTag = $this->bFlag.'\/'.$this->pfix; 
empty(Tags::$vars) && Tags::$vars = &$this->vars; 
} 
public function LoadTpl($tpl) { 
$this->file = $this->GetTplPath($tpl); 
Tags::$file = &$this->file; 
if (is_file($this->file)) { 
if ($this->GetTplHtml()) { 
$this->SetTplTags(); 
} else { 
exit('模板文件加载失败！'); 
} 
} else { 
exit('模板文件['.$this->file.']不存在！'); 
} 
} 
private function GetTplPath($tpl) { 
$this->folder = WEBSITE_DIRROOT. 
$GLOBALS['cfg_tpl_root']; 
return $this->folder.'/'.$tpl; 
} 
private function GetTplHtml() { 
$html = self::FmtTplHtml(file_get_contents($this->file)); 
if (!empty($html)) { 
$callFunc = Tags::$prefix.'Syntax'; 
$this->html = Tags::$callFunc($html, new Template()); 
} else { 
exit('模板文件内容为空！'); 
} return true; 
} 
static public function FmtTplHtml($html) { 
return preg_replace('/(\r)|(\n)|(\t)|(\s{2,})/is', '', $html); 
} 
public function Register($vars=array()) { 
if (is_array($vars)) { 
$this->vars = $vars; 
Tags::$vars = &$this->vars; 
} 
} 
public function Display($bool=false, $name="", $time=0) { 
if (!empty($this->html)) { 
if ($bool && !empty($name)) { 
if (!is_int($time)) $time = 600; 
$cache = new Cache($time); 
$cache->Set($name, $this->html); 
} 
echo $this->html; flush(); 
} else { 
exit('模板文件内容为空！'); 
} 
} 
public function SetAssign($souc, $info) { 
if (!empty($this->html)) { 
$this->html = str_ireplace($souc, self::FmtTplHtml($info), $this->html); 
} else { 
exit('模板文件内容为空！'); 
} 
} 
private function SetTplTags() { 
$this->SetPanelTags(); $this->SetTrunkTags(); $this->RegHatchVars(); 
} 
private function SetPanelTags() { 
$rule = $this->bTag.'([^'.$this->eFlag.']+)\/'.$this->eFlag; 
preg_match_all('/'.$rule.'/ism', $this->html, $out_matches); 
$this->TransTag($out_matches, 'panel'); unset($out_matches); 
} 
private function SetTrunkTags() { 
$rule = $this->bTag.'(\w+)\s*([^'.$this->eFlag.']*?)'.$this->eFlag. 
'((?:(?!'.$this->bTag.')[\S\s]*?|(?R))*)'.$this->eTag.'\\1\s*'.$this->eFlag; 
preg_match_all('/'.$rule.'/ism', $this->html, $out_matches); 
$this->TransTag($out_matches, 'trunk'); unset($out_matches); 
} 
private function TransTag($result, $type) { 
if (!empty($result[0])) { 
switch ($type) { 
case 'panel' : { 
for ($i = 0; $i < count($result[0]); $i ++) { 
$strTag = explode(' ', $result[1][$i], 2); 
if (strpos($strTag[0], '.')) { 
$itemArg = explode('.', $result[1][$i], 2); 
$callFunc = Tags::$prefix.ucfirst($itemArg[0]); 
if (method_exists('Tags', $callFunc)) { 
$html = Tags::$callFunc(chop($itemArg[1])); 
if ($html !== false) { 
$this->html = str_ireplace($result[0][$i], $html, $this->html); 
} 
} 
} else { 
$rule = '^([^\s]+)\s*([\S\s]+)$'; 
preg_match_all('/'.$rule.'/is', trim($result[1][$i]), $tmp_matches); 
$callFunc = Tags::$prefix.ucfirst($tmp_matches[1][0]); 
if (method_exists('Tags', $callFunc)) { 
$html = Tags::$callFunc($tmp_matches[2][0]); 
if ($html !== false) { 
$this->html = str_ireplace($result[0][$i], $html, $this->html); 
} 
} unset($tmp_matches); 
} 
} break; 
} 
case 'trunk' : { 
for ($i = 0; $i < count($result[0]); $i ++) { 
$callFunc = Tags::$prefix.ucfirst($result[1][$i]); 
if (method_exists('Tags', $callFunc)) { 
$html = Tags::$callFunc($result[2][$i], $result[3][$i]); 
$this->html = str_ireplace($result[0][$i], $html, $this->html); 
} 
} break; 
} 
default: break; 
} 
} else { 
return false; 
} 
} 
private function RegHatchVars() { 
$this->SetPanelTags(); 
} 
function __destruct() {} 
} 
?> 

标签解析类：（目前暂时提供data、list两种标签的解析，说明思路）

 
<?php 
/* 
* class: 标签解析类 
* author: 51JS.COM-ZMM 
* date: 2011.3.2 
* email: [email protected] 
* blog: http://www.cnblogs.com/cnzmm/ 
*/ 
class Tags { 
static private $attrs=null; 
static public $file, $vars, $rule, $prefix='TAG_'; 
static public function TAG_Syntax($html, $that) { 
$rule = $that->bTag.'if\s+([^'.$that->eFlag.']+)\s*'.$that->eFlag; 
$html = preg_replace('/'.$rule.'/ism', '<?php if (\\1) { ?>', $html); 
$rule = $that->bTag.'elseif\s+([^'.$that->eFlag.']+)\s*'.$that->eFlag; 
$html = preg_replace('/'.$rule.'/ism', '<?php } elseif (\\1) { ?>', $html); 
$rule = $that->bTag.'else\s*'.$that->eFlag; 
$html = preg_replace('/'.$rule.'/ism', '<?php } else { ?>', $html); 
$rule = $that->bTag.'loop\s+(\S+)\s+(\S+)\s*'.$that->eFlag; 
$html = preg_replace('/'.$rule.'/ism', '<?php foreach (\\1 as \\2) { ?>', $html); 
$rule = $that->bTag.'loop\s+(\S+)\s+(\S+)\s+(\S+)\s*'.$that->eFlag; 
$html = preg_replace('/'.$rule.'/ism', '<?php foreach (\\1 as \\2 => \\3) { ?>', $html); 
$rule = $that->eTag.'(if|loop)\s*'.$that->eFlag; 
$html = preg_replace('/'.$rule.'/ism', '<?php } ?>', $html); 
$rule = $that->bTag.'php\s*'.$that->eFlag.'((?:(?!'. 
$that->bTag.')[\S\s]*?|(?R))*)'.$that->eTag.'php\s*'.$that->eFlag; 
$html = preg_replace('/'.$rule.'/ism', '<?php \\1 ?>', $html); 
return self::TAG_Execute($html); 
} 
static public function TAG_List($attr, $html) { 
if (!empty($html)) { 
if (self::TAG_HaveTag($html)) { 
return self::TAG_DealTag($attr, $html, true); 
} else { 
return self::TAG_GetData($attr, $html, true); 
} 
} else { 
exit('标签{list}的内容为空！'); 
} 
} 
static public function TAG_Data($attr, $html) { 
if (!empty($html)) { 
if (self::TAG_HaveTag($html)) { 
return self::TAG_DealTag($attr, $html, false); 
} else { 
return self::TAG_GetData($attr, $html, false); 
} 
} else { 
exit('标签{data}的内容为空！'); 
} 
} 
static public function TAG_Execute($html) { 
ob_clean(); ob_start(); 
if (!empty(self::$vars)) { 
is_array(self::$vars) && 
extract(self::$vars, EXTR_OVERWRITE); 
} 
$file_inc = WEBSITE_DIRINC.'/buffer/'. 
md5(uniqid(rand(), true)).'.php'; 
if ($fp = fopen($file_inc, 'xb')) { 
fwrite($fp, $html); 
if (fclose($fp)) { 
include($file_inc); 
$html = ob_get_contents(); 
} unset($fp); 
} else { 
exit('模板解析文件生成失败！'); 
} ob_end_clean(); @unlink($file_inc); 
return $html; 
} 
static private function TAG_HaveTag($html) { 
$bool_has = false; 
$tpl_ins = new Template(); 
self::$rule = $tpl_ins->bTag.'([^'.$tpl_ins->eFlag.']+)\/'.$tpl_ins->eFlag; 
$bool_has = $bool_has || preg_match('/'.self::$rule.'/ism', $html); 
self::$rule = $tpl_ins->bTag.'(\w+)\s*([^'.$tpl_ins->eFlag.']*?)'.$tpl_ins->eFlag. 
'((?:(?!'.$tpl_ins->bTag.')[\S\s]*?|(?R))*)'.$tpl_ins->eTag.'\\1\s*'.$tpl_ins->eFlag; 
$bool_has = $bool_has || preg_match('/'.self::$rule.'/ism', $html); 
unset($tpl_ins); 
return $bool_has; 
} 
static private function TAG_DealTag($attr, $html, $list) { 
preg_match_all('/'.self::$rule.'/ism', $html, $out_matches); 
if (!empty($out_matches[0])) { 
$child_node = array(); 
for ($i = 0; $i < count($out_matches[0]); $i ++) { 
$child_node[] = $out_matches[3][$i]; 
$html = str_ireplace($out_matches[3][$i], '{-->>child_node_'.$i.'<<--}', $html); 
} 
$html = self::TAG_GetData($attr, $html, $list); 
for ($i = 0; $i < count($out_matches[0]); $i ++) { 
$html = str_ireplace('{-->>child_node_'.$i.'<<--}', $child_node[$i], $html); 
} 
preg_match_all('/'.self::$rule.'/ism', $html, $tmp_matches); 
if (!empty($tmp_matches[0])) { 
for ($i = 0; $i < count($tmp_matches[0]); $i ++) { 
$callFunc = self::$prefix.ucfirst($tmp_matches[1][$i]); 
if (method_exists('Tags', $callFunc)) { 
$temp = self::$callFunc($tmp_matches[2][$i], $tmp_matches[3][$i]); 
$html = str_ireplace($tmp_matches[0][$i], $temp, $html); 
} 
} 
} 
unset($tmp_matches); 
} 
unset($out_matches); return $html; 
} 
static private function TAG_GetData($attr, $html, $list=false) { 
if (!empty($attr)) { 
$attr_ins = new Attbt($attr); 
$attr_arr = $attr_ins->attrs; 
if (is_array($attr_arr)) { 
extract($attr_arr, EXTR_OVERWRITE); 
$source = table_name($source, $column); 
$rule = '\[field:\s*(\w+)\s*([^\]]*?)\s*\/?]'; 
preg_match_all('/'.$rule.'/is', $html, $out_matches); 
$data_str = ''; 
$data_ins = new DataSql(); 
$attr_where = $attr_order = ''; 
if (!empty($where)) { 
$where = str_replace(',', ' and ', $where); 
$attr_where = ' where '. $where; 
} 
if (!empty($order)) { 
$attr_order = ' order by '.$order; 
} else { 
$fed_name = ''; 
$fed_ins = $data_ins->GetFedNeedle($source); 
$fed_cnt = $data_ins->GetFedCount($fed_ins); 
for ($i = 0; $i < $fed_cnt; $i ++) { 
$fed_flag = $data_ins->GetFedFlag($fed_ins, $i); 
if (preg_match('/auto_increment/ism', $fed_flag)) { 
$fed_name = $data_ins->GetFedName($fed_ins, $i); 
break; 
} 
} 
if (!empty($fed_name)) 
$attr_order = ' order by '.$fed_name.' desc'; 
} 
if ($list == true) { 
if (empty($source) && empty($sql)) { 
exit('标签{list}必须指定source属性！'); 
} 
$attr_rows = $attr_page = ''; 
if ($rows > 0) { 
$attr_rows = ' limit 0,'.$rows; 
} 
if (!empty($sql)) { 
$data_sql = $sql; 
} else { 
$data_sql = 'select * from `'.$source.'`'. 
$attr_where.$attr_order.$attr_rows; 
} 
if ($pages=='true' && !empty($size)) { 
$data_num = $data_ins->GetRecNum($data_sql); 
$page_cnt = ceil($data_num / $size); 
global $page; 
if (!isset($page) || $page < 1) $page = 1; 
if ($page > $page_cnt) $page = $page_cnt; 
$data_sql = 'select * from `'.$source.'`'.$attr_where. 
$attr_order.' limit '.($page-1) * $size.','.$size; 
$GLOBALS['cfg_page_curr'] = $page; 
$GLOBALS['cfg_page_prev'] = $page - 1; 
$GLOBALS['cfg_page_next'] = $page + 1; 
$GLOBALS['cfg_page_nums'] = $page_cnt; 
if (function_exists('list_pagelink')) { 
$GLOBALS['cfg_page_list'] = list_pagelink($page, $page_cnt, 2); 
} 
} 
$data_idx = 0; 
$data_ret = $data_ins->SqlCmdExec($data_sql); 
while ($row = $data_ins->GetRecArr($data_ret)) { 
if ($skip > 0 && !empty($flag)) { 
$data_idx != 0 && 
$data_idx % $skip == 0 && 
$data_str .= $flag; 
} 
$data_tmp = $html; 
$data_tmp = str_ireplace('@idx', $data_idx, $data_tmp); 
for ($i = 0; $i < count($out_matches[0]); $i ++) { 
$data_tmp = str_ireplace($out_matches[0][$i], 
$row[$out_matches[1][$i]], $data_tmp); 
} 
$data_str .= $data_tmp; $data_idx ++; 
} 
} else { 
if (empty($source)) { 
exit('标签{data}必须指定source属性！'); 
} 
$data_sql = 'select * from `'.$source. 
'`'.$attr_where.$attr_order; 
$row = $data_ins->GetOneRec($data_sql); 
if (is_array($row)) { 
$data_tmp = $html; 
for ($i = 0; $i < count($out_matches[0]); $i ++) { 
$data_val = $row[$out_matches[1][$i]]; 
if (empty($out_matches[2][$i])) { 
$data_tmp = str_ireplace($out_matches[0][$i], $data_val, $data_tmp); 
} else { 
$attr_str = $out_matches[2][$i]; 
$attr_ins = new Attbt($attr_str); 
$func_txt = $attr_ins->attrs['function']; 
if (!empty($func_txt)) { 
$func_tmp = explode('(', $func_txt); 
if (function_exists($func_tmp[0])) { 
eval('$func_ret ='.str_ireplace('@me', 
'\''.$data_val.'\'', $func_txt)); 
$data_tmp = str_ireplace($out_matches[0][$i], $func_ret, $data_tmp); 
} else { 
exit('调用了不存在的函数！'); 
} 
} else { 
exit('标签设置属性无效！'); 
} 
} 
} 
$data_str .= $data_tmp; 
} 
} 
unset($data_ins); 
return $data_str; 
} else { 
exit('标签设置属性无效！'); 
} 
} else { 
exit('没有设置标签属性！'); 
} 
} 
static public function __callStatic($name, $args) { 
exit('标签{'.$name.'}不存在！'); 
} 
} 
?>