Hello team,

Today I added a real logger in Piwigo, based on https://github.com/katzgrau/KLogger (version 0.2 supporting PHP 5.2)

It currently only logs what was already logged by i.php and ws.php
What I would like is that if you have time you add log almost everywhere it would be interesting to have a trace of what is going on, mainly errors for production galleries but also debug infos for developpement.

I'll write a Wiki page about the logger but the main usage is

// 5 levels  (there are two more but I don't think we need this granularity)
$logger->info('message');
$logger->debug('message');
$logger->warning('message');
$logger->error('message');
$logger->critical('message');

// each method can take a array of info
$logger->info('message', array(
  'page' => $page,
  'user' => $user,
));

// each method can also take a "module" name (to separate core components, plugins, etc)
$logger->info('message', 'i.php');

$logger->info('message', 'i.php', array(
  'page' => $page,
  'user' => $user,
));

The logger generate one file by day in "_data/logs".
The filename contains an hash to prevent direct file access on unconfigured nginx servers (there is an .htaccess for Apache).
Up to 30 logs are kept (configurable).
The log level is also configurable (prod = ERROR, dev = DEBUG)

The last thing I plan is a logs viewer in "Maintenance" page for easy access by users when we ask them for the logs