Example Analysis of Interceptor in PHP

This article illustrates the interceptor usage of PHP. Share it for your reference. The details are as follows:

PHP provides several interceptors to be called when accessing undefined methods and properties, as follows:

1, __get ($property)
Function: Access to undefined properties is called

2, __set ($property, $value)
Function: Called when setting a value for an undefined property

3, __isset ($property)
Function: Called when isset () is called on an undefined property

4, __unset ($property)
Function: Called when unset () is called on an undefined property

5, __call ($method, $arg_array)
Function: Called when calling an undefined method

The following will explain the purpose of these interceptors through a small program:

class intercept_demo{

    private $xingming = "";

    private $age = 10;

   

    //  If accessed 1 Is not defined, a call is made to the get{$property} Corresponding method 

    function __get($property){

        $method = "get{$property}";

        if (method_exists($this, $method)){

            return $this->$method();

        }

    }
    //  If given 1 Undefined property setting values, the call is made to set{$property} Corresponding method 

    function __set($property, $value){

        $method = "set{$property}";

        if (method_exists($this, $method)){

            return $this->$method($value);

        }   

    }

   

    //  If the user calls an undefined property isset Method, 

    function __isset($property){

        $method = "isset{$property}";

        if (method_exists($this, $method)){

            return $this->$method();

        }

    }

   

    //  If the user calls an undefined property unset Method, 

    //  Is considered to call the corresponding unset{$property} Method 

    function __unset($property){

        $method = "unset{$property}";

        if (method_exists($this, $method)){

            return $this->$method();

        }

    }

   

    function __call($method, $arg_array){

        if (substr($method,0,3)=="get"){

            $property = substr($method,3);

            $property = strtolower(substr($property,0,1)).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 " Setting Properties Name For Li";

$intercept->Name = "Li";

echo "\$intercept->Name={$intercept->Name}";

echo "isset(Name)={$intercept->testIsset()}";

echo "";

echo " Empty attributes Name Value ";

unset($intercept->Name);

echo "\$intercept->Name={$intercept->Name}";

echo "";

echo " Invoke the undefined getAge Function ";

echo "age={$intercept->getAge()}";

I hope this article is helpful to everyone's PHP programming.