Update Client to mitigate _log being overwritten

Author: merk

CHANGELOG.md

@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file based on the
 ## [Unreleased](https://github.com/ruflin/Elastica/compare/3.1.1...HEAD)
 
 ### Backward Compatibility Breaks
+- \Elastica\Client::_log now has a second parameter for passing a Response for logging successful Requests. Note that overriding _log is now deprecated and customisation to logging should be handled with a custom LoggerInterface.
 
 ### Bugfixes
 - Fix php notice on `\Elastica\Index::getAliases()` if index has no aliases #1078
@@ -16,7 +17,7 @@ All notable changes to this project will be documented in this file based on the
 - Elastica\Client constructor now accepts a LoggerInterface and will log both successful and failed requests. #1069
 
 ### Deprecated
-
+- Configuring the logger in \Elastica\Client $config constructor is deprecated and will be removed. Use the $logger argument instead.
 
 ## [3.1.1](https://github.com/ruflin/Elastica/compare/3.1.0...3.1.1)
 

lib/Elastica/Client.php

@@ -642,11 +642,7 @@ public function request($path, $method = Request::GET, $data = array(), array $q
         } catch (ConnectionException $e) {
             $this->_connectionPool->onFail($connection, $e, $this);
 
-            $this->_logger->error('Elastica Request Failure', [
-                'exception' => $e,
-                'request' => $request->toArray(),
-                'retry' => $this->hasConnection()
-            ]);
+            $this->_log($e, $request);
 
             // In case there is no valid connection left, throw exception which caused the disabling of the connection.
             if (!$this->hasConnection()) {
@@ -656,15 +652,46 @@ public function request($path, $method = Request::GET, $data = array(), array $q
             return $this->request($path, $method, $data, $query);
         }
 
-        $this->_logger->debug('Elastica Request', [
-            'request' => $request->toArray(),
-            'response' => $response->getData(),
-            'responseStatus' => $response->getStatus()
-        ]);
+        $this->_log($request, $response);
 
         return $response;
     }
 
+    /**
+     * logging.
+     *
+     * @deprecated Overwriting Client->_log is deprecated. Handle logging functionality by using a custom LoggerInterface.
+     *
+     * @param mixed $context
+     * @param Response $response
+     */
+    protected function _log($context, Response $response = null)
+    {
+        if ($context instanceof ConnectionException) {
+            $this->_logger->error('Elastica Request Failure', [
+                'exception' => $context,
+                'request' => $context->getRequest()->toArray(),
+                'retry' => $this->hasConnection()
+            ]);
+
+            return;
+        }
+
+        if ($context instanceof Request) {
+            $this->_logger->debug('Elastica Request', [
+                'request' => $context->toArray(),
+                'response' => $response ? $response->getData() : null,
+                'responseStatus' => $response ? $response->getStatus() : null
+            ]);
+
+            return;
+        }
+
+        $this->_logger->debug('Elastica Request', [
+            'message' => $context
+        ]);
+    }
+
     /**
      * Optimizes all search indices.
      *