PHP 组件化编程技巧

PHP是一个很流行的Web编程语言，灵活，高效让它更具魅力。

但其在UI方便却有些力不从心，不仅是PHP，任何一种Web编程语言在设计UI都有类似的问题，宿主语言与HTML混和在一个文件中，大量重复的 HTML代码，毫无任何技术含量，但又非常的费时费力。于是我就希望能够对之前做过的PHP项目UI部分进行总结和归纳，将其封装为一个个小的组件（就像 Delphi中的组件一样），在界面上呈现为统一的风格，日后可以再针对这结组件编写多个CSS文件，提供“换肤”功能。

所有的组件都继承自AbatractComponent这个类，并实现其中的toString()和render()方法。AbatractComponent又有三个主要的子类，一个是容器类Continer，其又派生出Panel、PopPanel和GroupPanel等类，第二个是控件类Control，是所有可视控件类的父类，如Button、LinkButton等类，第三个则是列表类List，实现有列表，名-值对的UI。

AbstractComponent部分代码：

<?php 
/** 
* Component Library 
* 
* @author Chris Mao 
* @package Component 
* @description All components must be extened from the class 
* and override the both methods of toString. 
* @copyright Copyright (c) 2009 JueRui Soft Studio 
* 
**/ 
class AbstractComponent { 

/* 
* @var _style the component style's array 
* 
* @access protected 
* 
*/ 
protected $_style = array(); 
/* 
* @var _attributes the component attribute's string 
* 
* @access protected 
* 
*/ 
protected $_attributes = array(); 

/** 
* constructor function 
* 
* @access public 
* 
*/ 
public function __construct($options = null, $style = null) { 
if (!is_null($options) && (gettype($options) != "array")) { 
throw new Exception("The options must be a array!!"); 
} 
if (!empty($options) && is_array($options)) { 
if (array_key_exists("style", $options)) { 
if (is_array($options["style"])) { 
$this->_style = array_merge($this->_style, $options["style"]); 
} 
unset($options["style"]); 
} 
$this->_attributes = array_merge($this->_attributes, $options); 
} 
if (!empty($style) && is_array($style)) { 
$this->_style = array_merge($this->_style, $style); 
} 
} 

/** 
* set the component attributes 
* 
* @access protected 
* 
* @param $name attribute name 
* @param $value attribute value, option 
* 
* @return AbstractComponent 
*/ 
protected function setAttr($name, $value) { 
if (array_key_exists($name, $this->_attributes)) { 
unset($this->_attributes[$name]); 
} 
$this->_attributes[$name] = $value; 
return $this; 
} 

/** 
* get the component attributes' value 
* 
* @access protected 
* 
* @param $name attribute name 
* 
* @return string 
*/ 
protected function getAttr($name) { 
return array_key_exists($name, $this->_attributes) ? $this->_attributes[$name] : null; 
} 

/** 
* set the component style 
* 
* @access protected 
* 
* @param $name style name 
* @param $value style value, option 
* 
* @return AbstractComponent 
*/ 
protected function setStyle($name, $value) { 
if (array_key_exists($name, $this->_style)) { 
unset($this->_style[$name]); 
} 
$this->_style[$name] = $value; 
return $this; 
} 

/** 
* get the component style's value 
* 
* @access protected 
* 
* @param $name attribute name 
* 
* @return string 
*/ 
protected function getStyle($name) { 
return array_key_exists($name, $this->_style) ? $this->_style[$name] : null; 
} 

/** 
* convert the component all attributes to string like name = "value" 
* 
* @access protected 
* 
* @return string 
*/ 
protected function attributeToString() { 
//$s = array_reduce(; 
$s = ""; 
foreach($this->_attributes as $key => $value) { 
$s .= " $key=\"$value\" "; 
} 
return $s; 
} 

/** 
* convert the component style to string like style = "....." 
* 
* @access protected 
* 
* @return string 
*/ 
protected function styleToString() { 
if (empty($this->_style)) return ""; 
$s = ""; 
foreach($this->_style as $key => $value) { 
$s .= " $key: $value; "; 
} 
$s = " style=\"$s\" "; 
return $s; 
} 

/** 
* set or get the component attributes 
* 
* @access public 
* 
* @param $name attribute name 
* @param $value attribute value, option 
* 
* @return string || AbstractComponent 
*/ 
public function attr() { 
$name = func_get_arg(0); 
if (func_num_args() == 1) { 
return $this->getAttr($name); 
} 
else if (func_num_args() == 2) { 
$value = func_get_arg(1); 
return $this->setAttr($name, $value); 
} 
} 

/** 
* set or get the component style 
* 
* @access public 
* 
* @param $name style name 
* @param $value style value, option 
* 
* @return string || AbstractComponent 
*/ 
public function style() { 
$name = func_get_arg(0); 
if (func_num_args() == 1) { 
return $this->getStyle($name); 
} 
else if (func_num_args() == 2) { 
$value = func_get_arg(1); 
return $this->setStyle($name, $value); 
} 
} 

/** 
* return the HTML string 
* 
* @access public 
* 
* @return string 
**/ 
public function toString() { 
thorw New AbstractException("subclass must be override this method!!"); 
} 

/** 
* render the component 
* 
* @access public 
* 
* @return void 
**/ 
public function render() { 
echo $this->toString(); 
} 
}