今天单说codeigniter框架
举个官网控制器调用模板的例子
<?php
class Blog extends CI_Controller {
function index()
{
$data['title'] = "My Real Title";
$data['heading'] = "My Real Heading";
$this->load->view('blogview', $data);
}
}
?>
<html>
<head>
<title><?php echo $title;?></title>
</head>
<body>
<h1><?php echo $heading;?></h1>
</body>
</html>
感觉这种模式很不好，难道这就是传说中的控制器模板分离？这种模式只能忽悠刚刚入门的那些PHPer，先不论调用smarty之类的来反驳我，只是说他的自身特性，而且什么框架都能结合smarty来用。
以上的代码用PHP的一个函数就能实现了，请查阅extract函数的用法。
很多用codeigniter的PHPer估计就是冲着所谓写法优美去的，可以用连贯写法-> ->
究其实质，并没有对模板（视图）产生有多大的作用，
只是把变量全部先计算出来，换个名称，再在需要的时候，把新名称填入到所需地方。
然后个人在国外网站闲逛的时候呢，发现一个模板，它和codeigniter的这种模式有很大的相似性。模板名未知，就叫他template吧。你们可以看看，就可以对codeigniter原理有大致的了解吧
它的核心模板代码我写一下
<?php
//template.php
/**
* Copyright (c) 2003 Brian E. Lozier (brian@massassi.net)
*
* 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;
}
/**
* 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] = $value;
}
/**
* Open, parse, and return the template file.
*
* @param string string the template file name
*
* @return string
*/
function fetch($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 $contents;
}
}
}
?>
在该核心模板类中，同样用的是extract($this->vars); 函数来拆数组。
我们看他的“控制器”用法
<?php
//user_list.php
require_once('template.php');
/**
* This variable holds the file system path to all our template files.
*/
$path = './templates/';
/**
* Create a template object for the outer template and set its variables.
*/
$tpl = & new Template($path);
$tpl->set('title', 'User List');
/**
* Create a template object for the inner template and set its variables. The
* fetch_user_list() function simply returns an array of users.
*/
$body = & new Template($path);
$body->set('user_list', fetch_user_list());
/**
* Set the fetched template of the inner template to the 'body' variable in
* the outer template.
*/
$tpl->set('body', $body->fetch('user_list.tpl.php')); //这个是直接调用模板
/**
* Echo the results.
*/
echo $tpl->fetch('index.tpl.php');
/**
* Just a function to simulate the retrieval of a user list.
*/
function fetch_user_list() {
return array(
array('id' => 1,
'name' => 'bob',
'email' => 'bob@mozilla.org',
'banned' => false),
array('id' => 2,
'name' => 'judy',
'email' => 'judy@php.net',
'banned' => false),
array('id' => 3,
'name' => 'joe',
'email' => 'joe@opera.com',
'banned' => false),
array('id' => 4,
'name' => 'billy',
'email' => 'billy@wakeside.com',
'banned' => true),
array('id' => 5,
'name' => 'eileen',
'email' => 'eileen@slashdot.org',
'banned' => false));
}
?>
set就是赋值了。然后看它的“视图”是怎么输出的，就基本上完全和codeigniter类似了
//index.tpl.php
<html>
<head>
<title><?=$title;?></title>
</head>
<body>
<h2><?=$title;?></h2>
<?=$body;?>
</body>
</html>
//user_list.tpl.php
<table>
<tr>
<th>Id</th>
<th>Name</th>
<th>Email</th>
<th>Banned</th>
</tr>
<? foreach($user_list as $user): ?>
<tr>
<td align="center"><?=$user['id'];?></td>
<td><?=$user['name'];?></td>
<td><a href="mailto:<?=$user['email'];?>"><?=$user['email'];?></a></td>
<td align="center"><?=($user['banned'] ? 'X' : ' ');?></td>
</tr>
<? endforeach; ?>
</table>
详细的下载地址：http://download.csdn.net/detail/xjl756425616/3984218
