Multiple Monolog Loggers Cookbook

doc/cookbook/index.rst

@@ -14,6 +14,7 @@ The cookbook section contains recipes for solving specific problems.
     validator_yaml
     sub_requests
     error_handler
+    multiple_loggers
 
 Recipes
 -------
@@ -35,3 +36,5 @@ Recipes
 * :doc:`How to make sub-requests <sub_requests>`.
 
 * :doc:`How to convert errors to exceptions <error_handler>`.
+
+* :doc:`How to use multiple monolog loggers <multiple_loggers>`.

doc/cookbook/multiple_loggers.rst

+Using multiple monolog loggers
+==============================
+
+Having separate instances of `Monolog` for different parts of your system is
+often desirable and allows you to configure them independantly, allowing for fine
+grained control of where your logging goes and in what detail.
+
+This simple example allows you to quickly configure several monolog instances,
+using the bundled handler, but each with a different channel. 
+
+.. code-block:: php
+
+    $app['monolog.factory'] = $app->protect(function ($name) use ($app) {
+        $log = new $app['monolog.logger.class']($name);
+        $log->pushHandler($app['monolog.handler']);
+
+        return $log;
+    });
+
+    foreach (array('auth', 'payments', 'stats') as $channel) {
+        $app['monolog.'.$channel] = $app->share(function ($app) use ($channel) {
+            return $app['monolog.factory']($channel);
+        });
+    }
+
+As your application grows, or your logging needs for certain areas of the
+system become apparent, it should be straightforward to then configure that
+particular service separately, including your customisations.
+
+.. code-block:: php
+
+    $app['monolog.payments'] = $app->share(function ($app) {
+        $log = new $app['monolog.logger.class']('payments');
+        $handler = new StreamHandler($app['monolog.payments.logfile'], $app['monolog.payment.level']);
+        $log->pushHandler($handler);
+
+        return $log;
+    });
+
+Alternatively, you could attempt to make the factory more complicated, and rely
+on some conventions.
+
+.. code-block:: php
+
+    $app['monolog.factory'] = $app->protect(function ($name) use ($app) {
+        $log = new $app['monolog.logger.class']($name);
+
+        $handlers = isset($app['monolog.'.$name.'handlers'])
+            ? $app['monolog.'.$name.'handlers']
+            : array($app['monolog.handler']);
+
+        foreach ($handlers as $handler) {
+            $log->pushHandler($handler);
+        }
+
+        return $log;
+    });
+
+    $app['monolog.payments.handlers'] = $app->share(function ($app) {
+        return array(
+            new \Monolog\Handler\StreamHandler(__DIR__.'/../payments.log', \Monolog\Logger::DEBUG),
+        );
+    });
+
+