Fix Icinga\web\Hook

refs #4301

library/Icinga/Web/Hook.php

@@ -39,6 +39,19 @@ class Hook
      */
     protected static $instances = array();
 
+    /**
+     * @var string
+     */
+    public static $BASE_NS = 'Icinga\\Web\\Hook\\';
+
+    public static function clean()
+    {
+        self::$hooks = array();
+        self::$instances = array();
+        self::$BASE_NS = 'Icinga\\Web\\Hook\\';
+    }
+
+
     /**
      * Whether someone registered itself for the given hook name
      *
@@ -97,6 +110,86 @@ class Hook
         return self::$instances[$name];
     }
 
+    /**
+     * Create or return an instance of the hook
+     * @param string $name
+     * @param string $key
+     * @return \stdClass
+     */
+    public static function createInstance($name, $key)
+    {
+        if (!self::has($name, $key)) {
+            return null;
+        }
+        if (isset(self::$instances[$name][$key])) {
+            return self::$instances[$name][$key];
+        }
+        $class = self::$hooks[$name][$key];
+        try {
+            $instance = new $class();
+        } catch (\Exception $e) {
+            Log::debug(
+                'Hook "%s" (%s) (%s) failed, will be unloaded: %s',
+                $name,
+                $key,
+                $class,
+                $e->getMessage()
+            );
+            unset(self::$hooks[$name][$key]);
+            return null;
+        }
+        self::assertValidHook($instance, $name);
+        self::$instances[$name][$key] = $instance;
+        return $instance;
+    }
+
+    /**
+     * Test for a valid class name
+     * @param \stdClass $instance
+     * @param string $name
+     * @throws \Icinga\Exception\ProgrammingError
+     */
+    private static function assertValidHook(&$instance, $name)
+    {
+        $base_class = self::$BASE_NS . ucfirst($name);
+        if (!$instance instanceof $base_class) {
+            throw new ProgrammingError(
+                sprintf(
+                    '%s is not an instance of %s',
+                    get_class($instance),
+                    $base_class
+                )
+            );
+        }
+    }
+
+    /**
+     * Return all instances of a specific name
+     * @param string $name
+     * @return array
+     */
+    public static function all($name)
+    {
+        if (!self::has($name)) {
+            return array();
+        }
+        foreach (self::$hooks[$name] as $key => $hook) {
+            if (self::createInstance($name, $key) === null) {
+                return array();
+            }
+        }
+        return self::$instances[$name];
+    }
+
+    /**
+     * @param string $name
+     * @return \stdClass
+     */
+    public static function first($name)
+    {
+        return self::createInstance($name, key(self::$hooks[$name]));
+    }
+
     /**
      * Register your hook
      *
@@ -108,7 +201,7 @@ class Hook
      *
      * @return void
      */
-    public static function register($name, $class)
+    public static function register($name, $key, $class)
     {
         self::registerClass($name, $key, $class);
     }