NotificationModel refactoring

app/EventBuilder/EventIteratorBuilder.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Kanboard\EventBuilder;
+
+use Iterator;
+
+/**
+ * Class EventIteratorBuilder
+ *
+ * @package Kanboard\EventBuilder
+ * @author  Frederic Guillot
+ */
+class EventIteratorBuilder implements Iterator {
+    private $position = 0;
+    private $builders = array();
+
+    /**
+     * @return $this
+     */
+    public function withBuilder(BaseEventBuilder $builder)
+    {
+        $this->builders[] = $builder;
+        return $this;
+    }
+
+    public function rewind() {
+        $this->position = 0;
+    }
+
+    /**
+     * @return BaseEventBuilder
+     */
+    public function current() {
+        return $this->builders[$this->position];
+    }
+
+    public function key() {
+        return $this->position;
+    }
+
+    public function next() {
+        ++$this->position;
+    }
+
+    public function valid() {
+        return isset($this->builders[$this->position]);
+    }
+}