wiki.techinc.nl/docs/Logger.md
Timo Tijhof 9cb8bb611b debug: Improve docs, fix ingroup tags, clean up tests
* Remove redundant file-level description and ensure the class desc
  and ingroup tag are on the class block instead.
  Ref https://gerrit.wikimedia.org/r/q/owner:Krinkle+message:ingroup

* Widen `@covers` annotations in unit tests.
  Ref https://gerrit.wikimedia.org/r/q/owner:krinkle+is:merged+message:covers

* Create "Debug" documentation group, covering the debug/ directory.
  This will show up on doc.wikimedia.org under "Modules", where
  each class is listed, and the class page will also link back to
  the group as part of its breadcrumb navigation.

  Test with `php maintenance/mwdocgen.php --file docs/,includes/debug/`
  and then view /w/docs/html/

* Improve docs of various classes and explain relationships better.
  In particular, reformat to ensure each class has a oneline
  description that captures its essential function.

Change-Id: I5d1143a9244b7fd888e1dc31f0fd7965272aa900
2023-10-05 11:54:30 +00:00

70 lines
3.5 KiB
Markdown

Logger {#debuglogger}
=======
MediaWiki.Logger.LoggerFactory implements a [PSR-3] compatible message logging
system.
Named Psr.Log.LoggerInterface instances can be obtained from the
MediaWiki.Logger.LoggerFactory::getInstance() static method.
MediaWiki.Logger.LoggerFactory expects a class implementing the
MediaWiki.Logger.Spi interface to act as a factory for new
Psr.Log.LoggerInterface instances.
The "Spi" in MediaWiki.Logger.Spi stands for "service provider interface". An
SPI is an API intended to be implemented or extended by a third party. This
software design pattern is intended to enable framework extension and
replaceable components. It is specifically used in the
MediaWiki.Logger.LoggerFactory service to allow alternate PSR-3 logging
implementations to be easily integrated with MediaWiki.
The service provider interface allows the backend logging library to be
implemented in multiple ways. The $wgMWLoggerDefaultSpi global provides the
classname of the default MediaWiki.Logger.Spi implementation to be loaded at
runtime. This can either be the name of a class implementing the
MediaWiki.Logger.Spi with a zero argument constructor or a callable that will
return an MediaWiki.Logger.Spi instance. Alternately the
MediaWiki.Logger.LoggerFactory::registerProvider() static method can be called
to inject an MediaWiki.Logger.Spi instance into the LoggerFactory and bypass the
use of the default configuration variable.
The MediaWiki.Logger.LegacySpi class implements a service provider to generate
MediaWiki.Logger.LegacyLogger instances. The MediaWiki.Logger.LegacyLogger class
implements the PSR-3 logger interface and provides output and configuration
equivalent to the historic logging output of wfDebug, wfDebugLog, wfLogDBError
and wfErrorLog. The MediaWiki.Logger.LegacySpi class is the default service
provider defined in MainConfigSchema.php. It's usage should be transparent for
users who are not ready or do not wish to switch to a alternate logging
platform.
The MediaWiki.Logger.MonologSpi class implements a service provider to generate
Psr.Log.LoggerInterface instances that use the [Monolog] logging library. See
the PHP docs (or source) for MediaWiki.Logger.MonologSpi for details on the
configuration of this provider. The default configuration installs a null
handler that will silently discard all logging events. The documentation
provided by the class describes a more feature rich logging configuration.
## Classes
* MediaWiki.Logger.LoggerFactory: Factory for Psr.Log.LoggerInterface loggers
* MediaWiki.Logger.Spi: Service provider interface for
MediaWiki.Logger.LoggerFactory
* MediaWiki.Logger.NullSpi: MediaWiki.Logger.Spi for creating instances that
discard all log events
* MediaWiki.Logger.LegacySpi: Service provider for creating
MediaWiki.Logger.LegacyLogger instances
* MediaWiki.Logger.LegacyLogger: PSR-3 logger that mimics the historical output
and configuration of wfDebug, wfErrorLog and other global logging functions.
* MediaWiki.Logger.MonologSpi: MediaWiki.Logger.Spi for creating instances
backed by the monolog logging library
* MediaWiki.Logger.Monolog.LegacyHandler: Monolog handler that replicates the
udp2log and file logging functionality of wfErrorLog()
* MediaWiki.Logger.Monolog.WikiProcessor: Monolog log processor that adds host:
wfHostname() and wiki: WikiMap::getCurrentWikiId() to all records
## Globals
* $wgMWLoggerDefaultSpi: Configure which service provider LoggerFactory will
use for creating logger objects.
[PSR-3]: https://www.php-fig.org/psr/psr-3/
[Monolog]: https://github.com/Seldaek/monolog