Observe Pattern Implementation

Observer.php

<?php
/*
Observer Design Pattern - Weather Station Example

*/
abstract class Observer{
	public function update(){}
}

abstract  class Subject{

	public function register(Observer $obsInstance ){}

	public function notify(){}
}

class SmartPhone extends Observer{
	private $displayTemperature;
	private $displayHumidity;
	private $displayPressure;

	private $SubjectInstance;

	public function __construct(Subject $subjInstance){
		
		$this->SubjectInstance = $subjInstance;
		
		// Init Values
		$this->displayTemperature 	= 0;
		$this->displayHumidity		= 0;
		$this->displayPressure		= 0;
	}

	public function update(){
		$this->displayTemperature 	= $this->SubjectInstance->getTemperature();
		$this->displayHumidity		= $this->SubjectInstance->getHumidity();
		$this->displayPressure		= $this->SubjectInstance->getPressure();

		echo "\r\n========= SmartPhone Display =============";
		$this->display();
		echo "\r\n===========================================\r\n";				

	}

	public function display(){
		echo "\r\nSmartPhone Temperature: ".$this->displayTemperature;
		echo "\r\nSmartPhone Humidity: ".$this->displayHumidity;
		echo "\r\nSmartPhone Pressure: ".$this->displayPressure;

	}

}


class SmartWatch extends Observer{
	private $displayTemperature;
	private $displayHumidity;
	private $displayPressure;

	private $SubjectInstance;

	public function __construct(Subject $subjInstance){
		
		$this->SubjectInstance = $subjInstance;
		
		// Init Values
		$this->displayTemperature 	= 0;
		$this->displayHumidity		= 0;
		$this->displayPressure		= 0;
	}

	public function update(){
		$this->displayTemperature 	= $this->SubjectInstance->getTemperature();
		$this->displayHumidity		= $this->SubjectInstance->getHumidity();
		$this->displayPressure		= $this->SubjectInstance->getPressure();

		echo "\r\n========= SmartWatch Display =============";
		$this->display();
		echo "\r\n===========================================\r\n";		
	}

	public function display(){
		echo "\r\nSmartWatch Temperature: ".$this->displayTemperature;
		echo "\r\nSmartWatch Humidity: ".$this->displayHumidity;
		echo "\r\nSmartWatch Pressure: ".$this->displayPressure;

	}	
}



class WeatherStation extends Subject{
	
	private $ObserverArray;

	private $Temperature;
	private $Humidity;
	private $Pressure;	

	public function __construct(){
		$this->ObserverArray = array();

		// Init Values
		$this->Temperature 	= 0;
		$this->Humidity		= 0;
		$this->Pressure		= 0;		
	}

	public function register(Observer $obsInstance){

		array_push($this->ObserverArray, $obsInstance);

	}


	public function getTemperature(){
		return $this->Temperature;
	}

	public function getHumidity(){
		return $this->Humidity;
	}

	public function getPressure(){
		return $this->Pressure;
	}

	public function setValues($temp, $hum, $press){
		$this->Temperature 	= $temp;
		$this->Humidity 	= $hum;
		$this->Pressure 	= $press;

		$this->notify();
	}

	public function notify(){

		foreach ($this->ObserverArray as $ObserverObject) {
			$ObserverObject->update();
		}
	}
}



//Client Code


$WeatherStation = new WeatherStation();
$SmartWatch 	= new SmartWatch($WeatherStation);
$SmartPhone 	= new SmartPhone($WeatherStation);

$WeatherStation->register($SmartPhone);
$WeatherStation->register($SmartWatch);

$WeatherStation->setValues(18,102.2, 52);
$WeatherStation->setValues(20,103.1, 70);




?>