add AqlExpression

AqlExpression.php

@@ -0,0 +1,40 @@
+<?php
+/**
+ * User: evgen-d
+ * Date: 08.10.14
+ * Time: 16:00
+ */
+
+namespace devgroup\arangodb;
+
+use yii\base\Object;
+
+class AqlExpression extends Object
+{
+    /**
+     * @var string the AQL expression represented by this object
+     */
+    public $expression;
+
+
+    /**
+     * Constructor.
+     * @param string $expression the AQL expression represented by this object
+     * @param array $config additional configurations for this object
+     */
+    public function __construct($expression, $config = [])
+    {
+        $this->expression = $expression;
+        parent::__construct($config);
+    }
+
+    /**
+     * The PHP magic function converting an object into a string.
+     * @return string the AQL expression.
+     */
+    public function __toString()
+    {
+        return $this->expression;
+    }
+}
+