#6622 Logger refactoring: moved "log message processing" into "Processor" objects (to prepare the transition to Monolog)

4 files changed, 56 insertions, 13 deletions

diff --git a/config/global.php b/config/global.php
index 359519cab9..fc30ae5889 100644
--- a/config/global.php
+++ b/config/global.php
@@ -29,5 +29,8 @@ return array(
         }
         return '%level% %tag%[%datetime%] %message%';
     }),
+    'log.processors' => array(
+        DI\link('Piwik\Log\Processor\SprintfProcessor'),
+    ),
 
 );
diff --git a/core/Log.php b/core/Log.php
index a59d6857f6..54844f7dbb 100644
--- a/core/Log.php
+++ b/core/Log.php
@@ -140,10 +140,17 @@ class Log extends Singleton
     private $currentLogLevel = self::WARN;
 
     /**
+     * Processors process log messages before they are being sent to backends.
+     *
+     * @var callable[]
+     */
+    private $processors = array();
+
+    /**
      * The array of callbacks executed when logging a message. Each callback writes a log
      * message to a logging backend.
      *
-     * @var array
+     * @var callable[]
      */
     private $writers = array();
 
@@ -175,12 +182,14 @@ class Log extends Singleton
      * @param callable[] $writers
      * @param string $logMessageFormat
      * @param int $logLevel
+     * @param callable[] $processors
      */
-    public function __construct(array $writers, $logMessageFormat, $logLevel)
+    public function __construct(array $writers, $logMessageFormat, $logLevel, array $processors)
     {
         $this->writers = $writers;
         $this->logMessageFormat = $logMessageFormat;
         $this->currentLogLevel = $logLevel;
+        $this->processors = $processors;
     }
 
     /**
@@ -286,17 +295,9 @@ class Log extends Singleton
         }
 
         $datetime = date("Y-m-d H:i:s");
-        if (is_string($message)
-            && !empty($sprintfParams)
-        ) {
-            // handle array sprintf parameters
-            foreach ($sprintfParams as &$param) {
-                if (is_array($param)) {
-                    $param = json_encode($param);
-                }
-            }
 
-            $message = vsprintf($message, $sprintfParams);
+        foreach ($this->processors as $processor) {
+            $message = $processor($message, $sprintfParams, $level);
         }
 
         if (version_compare(phpversion(), '5.3.6', '>=')) {
diff --git a/core/Log/LoggerFactory.php b/core/Log/LoggerFactory.php
index c66e1bac81..3e48c63fdf 100644
--- a/core/Log/LoggerFactory.php
+++ b/core/Log/LoggerFactory.php
@@ -15,6 +15,7 @@ use Piwik\Log;
 use Piwik\Log\Backend\DatabaseBackend;
 use Piwik\Log\Backend\FileBackend;
 use Piwik\Log\Backend\ScreenBackend;
+use Piwik\Log\Processor\SprintfProcessor;
 use Piwik\Piwik;
 
 class LoggerFactory
@@ -33,8 +34,9 @@ class LoggerFactory
         $logFilePath = self::getLogFilePath($logConfig, $container);
         $logLevel = self::getLogLevel($logConfig, $container);
         $writers = self::getLogWriters($logConfig, $messageFormat, $logFilePath);
+        $processors = $container->get('log.processors');
 
-        return new Log($writers, $messageFormat, $logLevel);
+        return new Log($writers, $messageFormat, $logLevel, $processors);
     }
 
     private static function getLogLevel($logConfig, ContainerInterface $container)
diff --git a/core/Log/Processor/SprintfProcessor.php b/core/Log/Processor/SprintfProcessor.php
new file mode 100644
index 0000000000..8ec0d61db2
--- /dev/null
+++ b/core/Log/Processor/SprintfProcessor.php
@@ -0,0 +1,37 @@
+<?php
+/**
+ * Piwik - free/libre analytics platform
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+
+namespace Piwik\Log\Processor;
+
+/**
+ * Processes a log message using `sprintf()`.
+ */
+class SprintfProcessor
+{
+    public function __invoke($message, array $parameters = array(), $level)
+    {
+        if (is_string($message) && !empty($parameters)) {
+            $parameters = $this->ensureParametersAreStrings($parameters);
+
+            $message = vsprintf($message, $parameters);
+        }
+
+        return $message;
+    }
+
+    private function ensureParametersAreStrings(array $parameters)
+    {
+        foreach ($parameters as &$param) {
+            if (is_array($param)) {
+                $param = json_encode($param);
+            }
+        }
+
+        return $parameters;
+    }
+}