Merge pull request #722 from flightphp/eventdispatcher-rework

Simplify EventDispatcher methods and remove redundant descriptions

flight/core/EventDispatcher.php

@@ -6,134 +6,83 @@ namespace flight\core;
 
 class EventDispatcher
 {
-    /** @var self|null Singleton instance of the EventDispatcher */
     private static ?self $instance = null;
 
-    /** @var array<string, array<int, callable>> */
+    /** @var array<string, callable[]> */
     protected array $listeners = [];
 
-    /**
-     * Singleton instance of the EventDispatcher.
-     *
-     * @return self
-     */
     public static function getInstance(): self
     {
         if (self::$instance === null) {
             self::$instance = new self();
         }
+
         return self::$instance;
     }
 
-    /**
-     * Register a callback for an event.
-     *
-     * @param string $event Event name
-     * @param callable $callback Callback function
-     */
     public function on(string $event, callable $callback): void
     {
-        if (isset($this->listeners[$event]) === false) {
-            $this->listeners[$event] = [];
-        }
+        $this->listeners[$event] ??= [];
         $this->listeners[$event][] = $callback;
     }
 
     /**
-     * Trigger an event with optional arguments.
-     *
-     * @param string $event Event name
-     * @param mixed ...$args Arguments to pass to the callbacks
-     *
+     * @param mixed ...$args Arguments to pass to the listeners.
      * @return mixed
      */
     public function trigger(string $event, ...$args)
     {
-        $result = null;
-        if (isset($this->listeners[$event]) === true) {
-            foreach ($this->listeners[$event] as $callback) {
-                $result = call_user_func_array($callback, $args);
-
-                // If you return false, it will break the loop and stop the other event listeners.
-                if ($result === false) {
-                    break; // Stop executing further listeners
-                }
+        $listenerReturnValue = null;
+
+        foreach ($this->getListeners($event) as $listener) {
+            $listenerReturnValue = $listener(...$args);
+
+            if ($listenerReturnValue === false) {
+                break;
             }
         }
-        return $result;
+
+        return $listenerReturnValue;
     }
 
-    /**
-     * Check if an event has any registered listeners.
-     *
-     * @param string $event Event name
-     *
-     * @return bool True if the event has listeners, false otherwise
-     */
     public function hasListeners(string $event): bool
     {
-        return isset($this->listeners[$event]) === true && count($this->listeners[$event]) > 0;
+        return (
+            isset($this->listeners[$event])
+            && is_array($this->listeners[$event])
+            && count($this->listeners[$event])
+        );
     }
 
-    /**
-     * Get all listeners registered for a specific event.
-     *
-     * @param string $event Event name
-     *
-     * @return array<int, callable> Array of callbacks registered for the event
-     */
+    /** @return callable[] */
     public function getListeners(string $event): array
     {
         return $this->listeners[$event] ?? [];
     }
 
-    /**
-     * Get a list of all events that have registered listeners.
-     *
-     * @return array<int, string> Array of event names
-     */
+    /** @return string[] */
     public function getAllRegisteredEvents(): array
     {
         return array_keys($this->listeners);
     }
 
-    /**
-     * Remove a specific listener for an event.
-     *
-     * @param string   $event    the event name
-     * @param callable $callback the exact callback to remove
-     *
-     * @return void
-     */
     public function removeListener(string $event, callable $callback): void
     {
-        if (isset($this->listeners[$event]) === true && count($this->listeners[$event]) > 0) {
-            $this->listeners[$event] = array_filter($this->listeners[$event], function ($listener) use ($callback) {
-                return $listener !== $callback;
-            });
-            $this->listeners[$event] = array_values($this->listeners[$event]); // Re-index the array
+        if (!$this->hasListeners($event)) {
+            return;
         }
+
+        $this->listeners[$event] = array_values(array_filter(
+            $this->getListeners($event),
+            static fn(callable $listener): bool => $listener !== $callback,
+        ));
     }
 
-    /**
-     * Remove all listeners for a specific event.
-     *
-     * @param string $event the event name
-     *
-     * @return void
-     */
     public function removeAllListeners(string $event): void
     {
-        if (isset($this->listeners[$event]) === true) {
         unset($this->listeners[$event]);
     }
-    }
 
-    /**
-     * Remove the current singleton instance of the EventDispatcher.
-     *
-     * @return void
-     */
     public static function resetInstance(): void
     {
         self::$instance = null;