PHP的拦截器实例分析

// 若访问一个未定义的属性，则将调用get{$property}对应的方法
function __get($property){
$method = "get{$property}";
if (method_exists($this,$method)){
return $this->$method();
}
}

// 若给一个未定义的属性设置值，则将调用set{$property}对应的方法 function __set($property,$value){ $method = "set{$property}"; if (method_exists($this,$method)){ return $this->$method($value); } }

// 若用户对未定义的属性调用isset方法，
function __isset($property){
$method = "isset{$property}";
if (method_exists($this,$method)){
return $this->$method();
}
}

// 若用户对未定义的属性调用unset方法，
// 则认为调用对应的unset{$property}方法
function __unset($property){
$method = "unset{$property}";
if (method_exists($this,$method)){
return $this->$method();
}
}

function __call($method,$arg_array){
if (substr($method,3)=="get"){
$property = substr($method,3);
$property = strtolower(substr($property,1)).substr($property,1);
return $this->$property;
}
}

function testIsset(){
return isset($this->Name);
}

function getName(){
return $this->xingming;
}

function setName($value){
$this->xingming = $value;
}

function issetName(){
return !is_null($this->xingming);
}

function unsetName(){
$this->xingming = NULL;
}
}

$intercept = new intercept_demo(); echo "设置属性Name为Li"; $intercept->Name = "Li"; echo "$intercept->Name={$intercept->Name}"; echo "isset(Name)={$intercept->testIsset()}"; echo ""; echo "清空属性Name值"; unset($intercept->Name); echo "$intercept->Name={$intercept->Name}"; echo ""; echo "调用未定义的getAge函数"; echo "age={$intercept->getAge()}";