PHP的拦截器实例分析

class intercept_demo{
??? private $xingming = "";
??? private $age = 10;
??
??? // 若拜访一个未定义的属性,则将调用get{$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()}";