add AqlExpression

Serializer.php

@@ -0,0 +1,59 @@
+<?php
+/**
+ * User: evgen-d
+ * Date: 08.10.14
+ * Time: 16:04
+ */
+
+namespace devgroup\arangodb;
+
+use yii\base\Arrayable;
+
+class Serializer
+{
+    public static function encode($value, $options = 0)
+    {
+        $expressions = [];
+        $value = static::processData($value, $expressions, uniqid());
+        $json = json_encode($value, $options);
+
+        return empty($expressions) ? $json : strtr($json, $expressions);
+    }
+
+    protected static function processData($data, &$expressions, $expPrefix)
+    {
+        if (is_object($data)) {
+            if ($data instanceof AqlExpression) {
+                $token = "!{[$expPrefix=" . count($expressions) . ']}!';
+                $expressions['"' . $token . '"'] = $data->expression;
+
+                return $token;
+            } elseif ($data instanceof \JsonSerializable) {
+                $data = $data->jsonSerialize();
+            } elseif ($data instanceof Arrayable) {
+                $data = $data->toArray();
+            } else {
+                $result = [];
+                foreach ($data as $name => $value) {
+                    $result[$name] = $value;
+                }
+                $data = $result;
+            }
+
+            if ($data === []) {
+                return new \stdClass();
+            }
+        }
+
+        if (is_array($data)) {
+            foreach ($data as $key => $value) {
+                if (is_array($value) || is_object($value)) {
+                    $data[$key] = static::processData($value, $expressions, $expPrefix);
+                }
+            }
+        }
+
+        return $data;
+    }
+}
+