Add SmartSerializer and make default

SmartSerializer introspects the response headers to determine if
the response is JSON or text.  If the data is JSON, it is decoded.
Otherwise it is returned as a string.

The other serializers and interface had to be modified to allow passing
of headers.  The headers are not currently used

src/Elasticsearch/Serializers/ArrayToJSONSerializer.php

@@ -48,10 +48,11 @@ public function serialize($data)
      * Deserialize JSON into an assoc array
      *
      * @param string $data JSON encoded string
+     * @param array  $headers Response Headers
      *
      * @return array
      */
-    public function deserialize($data)
+    public function deserialize($data, $headers)
     {
         return json_decode($data, true);
 

src/Elasticsearch/Serializers/EverythingToJSONSerializer.php

@@ -40,10 +40,11 @@ public function serialize($data)
      * Deserialize JSON into an assoc array
      *
      * @param string $data JSON encoded string
+     * @param array  $headers Response headers
      *
      * @return array
      */
-    public function deserialize($data)
+    public function deserialize($data, $headers)
     {
         return json_decode($data, true);
 

src/Elasticsearch/Serializers/SerializerInterface.php

@@ -12,5 +12,5 @@ interface SerializerInterface
     public function serialize($data);
 
 
-    public function deserialize($data);
+    public function deserialize($data, $headers);
 }

src/Elasticsearch/Serializers/SmartSerializer.php

@@ -0,0 +1,73 @@
+<?php
+/**
+ * User: zach
+ * Date: 5/1/13
+ * Time: 10:00 PM
+ */
+
+namespace Elasticsearch\Serializers;
+
+/**
+ * Class SmartSerializer
+ *
+ * @category Elasticsearch
+ * @package  Elasticsearch\Serializers\JSONSerializer
+ * @author   Zachary Tong <[email protected]>
+ * @license  http://www.apache.org/licenses/LICENSE-2.0 Apache2
+ * @link     http://elasticsearch.org
+ */
+class SmartSerializer implements SerializerInterface
+{
+
+
+    /**
+     * Serialize assoc array into JSON string
+     *
+     * @param string|array $data Assoc array to encode into JSON
+     *
+     * @return string
+     */
+    public function serialize($data)
+    {
+        if (is_string($data) === true) {
+            return $data;
+        } else {
+            $data = json_encode($data);
+            if ($data === '[]') {
+                return '{}';
+            } else {
+                return $data;
+            }
+        }
+
+
+    }
+
+
+    /**
+     * Deserialize by introspecting content_type.  Tries to deserialize JSON,
+     * otherwise returns string
+     *
+     * @param string $data JSON encoded string
+     * @param array  $headers Response Headers
+     *
+     * @return array
+     */
+    public function deserialize($data, $headers)
+    {
+        if (isset($headers['content_type']) === true) {
+            if (strpos($headers['content_type'], 'json') !== false) {
+                return json_decode($data, true);
+            } else {
+                //Not json, return as string
+                return $data;
+            }
+
+        } else {
+            //No content headers, assume json
+            return json_decode($data, true);
+        }
+
+
+    }
+}

src/Elasticsearch/Transport.php

@@ -164,7 +164,7 @@ public function performRequest($method, $uri, $params = null, $body = null)
             $connection->markAlive();
             $this->retryAttempts = 0;
 
-            $data = $this->serializer->deserialize($response['text']);
+            $data = $this->serializer->deserialize($response['text'], $response['info']);
 
             return array(
                 'status' => $response['status'],