Added method isLektor()

This method checks if a given user is a lector (and eventually if is
fix employed)

application/models/ressource/Mitarbeiter_model.php

@@ -11,4 +11,33 @@ class Mitarbeiter_model extends DB_Model
 		$this->dbTable = 'public.tbl_mitarbeiter';
 		$this->pk = 'mitarbeiter_uid';
 	}
+
+    /**
+     * Checks if the user is a lector.
+     * @param string $uid
+     * @param boolean null $fixangestellt
+     * @return bool
+     */
+    public function isLektor($uid, $fixangestellt = null)
+    {
+        $this->addSelect('1');
+
+        if (is_bool($fixangestellt))
+        {
+            $result = $this->loadWhere(array('mitarbeiter_uid' => $uid, 'lektor' => true, 'fixangestellt' => $fixangestellt));
+        }
+        else    // Default: if lektor is true
+        {
+            $result = $this->loadWhere(array('mitarbeiter_uid' => $uid, 'lektor' => true));
+        }
+
+        if(hasData($result))
+        {
+            return true;
+        }
+        else
+        {
+            return false;
+        }
+    }
 }