PHP in-depth viewer mode

# # # #观察者模式 * Designed to let an object track a state, know how the state changes, once the state changes, all subscribed objects can be notified # # #使用SPL实现观察者模式 * Splsubject interface has three abstract methods attach (), Detach (), notify () These methods do not return any results * Splobserver interface has a method update () it will get the latest state of the subject state and hand it to the Observer instance * Splobjectstorage Class is described as a mapping from an object to a set of data or objects
 Observers = new Splobjectstorage ();    }//Add observer public Function attach (\splobserver $observer) {$this->observers->attach ($observer);    }//Delete Observer public function detach (\splobserver $observer) {$this->observers->detach ($observer); }//Notification forward public function notify () {foreach ($this->observers as $observer) {$observer->update        ($this);    }}//Set data public function SetData ($dataNow) {$this->data = $dataNow;    } public Function GetData () {return $this->data; }}//SPL Specific Viewer class Concreteobserver implements splobserver{Public Function update (Splsubject $subject) {echo $    Subject->getdata (); }}class client{Public Function __construct () {echo "
Create three new concrete observers ";        Create observer $ob 1 = new Concreteobserver ();        $ob 2 = new Concreteobserver ();        $ob 3 = new Concreteobserver ();        $subject = new ConcreteSubject ();        $subject->setobservers (); $subject->setdata ("Here is U data".)
");        $subject->attach ($ob 1);        $subject->attach ($ob 2);        $subject->attach ($ob 3);        $subject->notify (); echo "
Reset Data and Reattach OB3
"; $subject->setdata ("More data, only".)
");        $subject->attach ($ob 3);        $subject->attach ($ob 2);    $subject->notify (); }} $data = new Client (); "' # # #自由的PHP和观察者模式"
 Observers, $obser);        The Public Function Detachobser (Observer $obser) {//Removes data from the array $position = 0;            foreach ($this->observers as $viwer) {+ + $position;            if ($viwer = = $obser) {array_splice ($this->observers, ($position), 1);            }}} public function notify () {foreach ($this->observers as $viewer) {//Call the Update method        $viewer->update ($this); }}}class ConcreteSubject extends subject{public function setState ($stateSet) {$this->statenow = $stateSe    T    } public Function GetState () {return $this->statenow;    }}class Concreteobserverdt implements observer{private $currentState;        Public Function Update (Subject $subject) {$this->currentstate = $subject->getstate ();    echo "DT";    }}class Concreobservertablet implements observer{private $currentState; Public Function Update (Subject $subject) {$this->curreNtstate = $subject->getstate ();    echo "tablet";    }}class Concreobserverphone implements observer{private $currentState;        Public Function Update (Subject $subject) {$this->currentstate = $subject->getstate ();    echo "Phone";        }}class client{Public Function __construct () {$sub = new ConcreteSubject ();        $ob 1 = new Concreobserverphone ();        $ob 2 = new Concreobservertablet ();        $ob 3 = new Concreteobserverdt ();        $sub->attachobser ($ob 1);        $sub->attachobser ($ob 2);        $sub->attachobser ($ob 3);        $sub->setstate ("fuck");        $sub->detachobser ($ob 1);    $sub->notify (); }} $data = new Client ();

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