log4php logger->setLevel() doesn't work - php

Question

Not sure why this very simple thing doesn't work -
$logger = Logger::getLogger("test");
$logger->setLevel(LoggerLevel::getLevelWarn());
$logger->debug("debug");
$logger->info("info");
$logger->warn("warn");
This will print:
DEBUG - debug
INFO - info
WARN - warn
I must be doing something obviously stupid! I would assume that neither the debug nor info logging would come through with the setLevel() to warn was present.
Thoughts?
I would like to have multiple loggers that each log at different levels. Not sure why this is so hard...

Answer 1

If you check the created Logger object (after you initialize it with Logger::getLogger("test");), you'll see that it already has a parent Logger, object(LoggerRoot). This object has its level set to DEBUG, and that's actually the logger that prints the debug and info messages.
One possible approach is to use a RootLogger instead:
$logger = Logger::getRootLogger();
$logger->setLevel(LoggerLevel::getLevelWarn());
$logger->debug("debug");
$logger->info("info");
$logger->warn("warn");
Another approach is to configure rootLogger so that it will log only messages of some very high level (FATAL), and let your loggers to set levels appropriate to them. But in that case you need to add your own appenders to those (it's appenders that do the logging job; loggers just manage them). Again, one possible approach:
$rootLogger = Logger::getRootLogger();
$rootLogger->setLevel(LoggerLevel::getLevelFatal());
$logger = Logger::getLogger('some');
$logger->addAppender($rootLogger->getAppender('default'));
$logger->setLevel(LoggerLevel::getLevelInfo());
$logger->debug('debug'); // won't print
$logger->info('info'); // will be printed
$logger->warn('warn'); // will be printed too
$logger->fatal('fatal dup'); // will be printed TWICE:
// with $logger, then with $rootLogger
$logger->setAdditivity(false); // switching off log event propagation
$logger->fatal('fatal once'); // will be printed ONCE
But it you actually need a complex hierarchy of loggers, I'd highly suggest configuring them all at once, following the approach described in this section of log4php documentation.