March 9, 2017

Dynamic Getters and Setters in PHP

Use dynamic accessor-methods in a PHP class with one simple code-block. You don't have to create them over and over again with copy/paste anymore. Kinda like Lombok[1] does for Java.

Example 1

class Person {
    private $firstname;
    private $lastname;
    private $birthdate;
    private $externalReference;

    /**
     * Dynamic getters and setters
     */
    public function __call($method, $params){
        $prefix = substr($method, 0, 3);
        $var = lcfirst(substr($method, 3));
        if($prefix == 'get'){
            return $this->{$var};
        }
        else if($prefix == 'set'){
            $this->{$var} = $params[0];
        }
        else if($prefix == 'out'){
            return htmlspecialchars($this->$var, ENT_QUOTES, 'UTF-8'); //prevent XSS
        }
    }
}

Simple class with use of PHP's magic method __call.

$person = new Person();
$person->setFirstname('John');
$person->setLastname('Doe');
$person->setBirthdate(DateTime::createFromFormat('Y-m-d H:i:s','1955-11-05 00:00:00'));
$person->setExternalReference(1000);

Instantiate the class and set the values

object(Person)[1]
  private 'firstname' => string 'John' (length=4)
  private 'lastname' => string 'Doe' (length=3)
  private 'birthdate' => 
    object(DateTime)[2]
      public 'date' => string '1955-11-05 00:00:00.000000' (length=26)
      public 'timezone_type' => int 0
      public 'timezone' => string 'Hill Valley' (length=13)
  private 'externalReference' => int 1000

Output of the instance

Extended example

class BestClassEver {
    /**
     * Dynamic getters and setters
     */
    public function __call($method, $params){
        $prefix = substr($method, 0, 3);
        $var = lcfirst(substr($method, 3));
        if($prefix == 'get'){
            return $this->{$var};
        }
        else if($prefix == 'set'){
            $this->{$var} = $params[0];
        }
        else if($prefix == 'out'){
            return htmlspecialchars($this->$var, ENT_QUOTES, 'UTF-8'); //prevent XSS
        }
    }
}

class Person extends BestClassEver {
    protected $firstname;
    protected $lastname;
    protected $birthdate;
    protected $externalReference;
}

Put the code-block into a superclass. (Notice the change of the access-modifier by the class-properties)

$person = new Person();
$person->setFirstname('John');
$person->setLastname('Doe');
$person->setBirthdate(DateTime::createFromFormat('Y-m-d H:i:s','1955-11-05 00:00:00'));
$person->setExternalReference(1000);

Instantiate the class and set the values

object(Person)[1]
  protected 'firstname' => string 'John' (length=4)
  protected 'lastname' => string 'Doe' (length=3)
  protected 'birthdate' => 
    object(DateTime)[2]
      public 'date' => string '1955-11-05 00:00:00.000000' (length=26)
      public 'timezone_type' => int 0
      public 'timezone' => string 'Hill Valley' (length=13)
  protected 'externalReference' => int 1000

Output of the instance

Sources:

[1] https://projectlombok.org

Tags: php, oop

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human, software engineer, tech enthusiast, security researcher

E-Mail: blog@cipher.digital