Method chaining in php5

[jpadie]

I don't know why I didn't think of this years ago but it is possible to method chain in php5. not just between subsidiary objects but within the same object.

in case it's useful for anyone consider this

<?php 

class example{
	
	public $name;
	public $address;
	public $telephone;
	public $email;
	
	public function __call($name, $value){
		if (substr(strtolower($name), 0, 3) == 'set'){
			$property = substr($name,3);
			if ($this->isProperty($property)){
				$this->$property  = $value[0];
				[red]return $this;[/red]
			}
		}
	}
	private function isProperty($property){
		$vars = array_map('strtolower', array_keys(get_object_vars($this)));
		return (in_array(strtolower($property), $vars));
	}
	
	public function output(){
		echo "<pre>" . print_r($this, true);
	}
}

$e = new example;
$e	->setname('Justin')
	->setaddress('my address')
	->settelephone('020 1234 5678')
	->setemail('myemail@mydomain.com')
	->output();
?>

the key bit is for your method to return an instance of its containing object.

the above code uses method overloading to create a method of setting properties. there are better ways to do this but the point of this code was to show how to chain methods rather than anything else.

 

[parkers]

Agree that this is useful to know and would like to add that method chaining can make code more compact and robust. As a simple example:

$object->methodA()->methodB();

The key is to return $this from methods "methodA" and "methodB". Any method that returns the object is suitable for chaining.


Steven Parker

http://www.stevenp1974.co.uk