Behavioral Observer FavoritePatternsGossip

Behavioral/Observer/FavoritePatternsGossip.php

@@ -0,0 +1,67 @@
+<?php
+
+abstract class AbstractSubject {
+    abstract public function attach(AbstractObserver $observerIn): void;
+    abstract public function detach(AbstractObserver $observerIn): void;
+    abstract public function notify(): void;
+}
+
+abstract class AbstractObserver {
+    abstract function update(AbstractSubject $subjectIn): void;
+}
+
+class PatternSubject extends AbstractSubject
+{
+    private ?string $favorites = null;
+    private array $observers = [];
+
+    public function attach(AbstractObserver $observerIn): void
+    {
+        $this->observers[] = $observerIn;
+    }
+
+    public function detach(AbstractObserver $observerIn): void
+    {
+        $oKey = array_search($observerIn, $this->observers);
+        if (false !== $oKey) {
+            unset($this->observers[$oKey]);
+        }
+    }
+
+    public function notify(): void
+    {
+        foreach ($this->observers as $observer) {
+            $observer->update($this);
+        }
+    }
+
+    public function updateFavorites(string $newFavorites): void
+    {
+        $this->favorites = $newFavorites;
+        $this->notify();
+    }
+
+    public function getFavorites(): string
+    {
+        return $this->favorites;
+    }
+}
+
+class PatternObserver extends AbstractObserver
+{
+    public function update(AbstractSubject $subject): void
+    {
+        echo '**OBSERVADOR - ALERTA DE CHISMES NUEVOS PATRONES FAVORITOS**<br>';
+        echo 'Nuevos patrones favoritos: ' . $subject->getFavorites() . '<br>';
+    }
+}
+
+$patternGossiper = new PatternSubject();
+$patternGossipFan = new PatternObserver();
+
+$patternGossiper->attach($patternGossipFan);
+$patternGossiper->updateFavorites('abstract factory, decorator, visitor');
+$patternGossiper->updateFavorites('abstract factory, observer, decorator');
+
+$patternGossiper->detach($patternGossipFan);
+$patternGossiper->updateFavorites('abstract factory, observer, visitor');