Simple logger class to:
- Keep track of log entries.
- Keep track of timings with
- Optionally write log entries in real-time to file or to screen.
- Optionally dump the log to file in one go at any time.
Log entries can be added with any of the following methods:
debug( $message, $title = '' )> a diagnostic message intended for the developer
info( $message, $title = '' )> an informational message intended for the user
warning( $message, $title = '' )> a warning that something might go wrong
error( $message, $title = '' )> explain why the program is going to crash
$title argument is optional; if present, it will be prepended to the message: "$title => $message".
The following code:
Logger::$log_level = 'debug'; Logger::debug( "variable x is false" ); Logger::info( "program started" ); Logger::warning( "variable not set, something bad might happen" ); Logger::error( "file not found, exiting" );
will print to STDOUT the following lines:
$> 2021-07-21T11:11:03+02:00 [DEBUG] : variable x is false $> 2021-07-21T11:11:03+02:00 [INFO] : program started $> 2021-07-21T11:11:03+02:00 [WARNING] : variable not set, something bad might happen $> 2021-07-21T11:11:03+02:00 [ERROR] : file not found, exiting
You can keep track of elapsed time by using the
Logger::time(); sleep(1); Logger::timeEnd();
$> 2022-04-19T17:26:26+00:00 [DEBUG] : Elapsed time => 1.003163 seconds
If you need to time different processes at the same time, you can use named timers.
Logger::time('outer timer'); sleep(1); Logger::time('inner timer'); sleep(1); Logger::timeEnd('inner timer'); Logger::timeEnd('outer timer');
$> 2022-04-19T17:32:15+00:00 [DEBUG] : Elapsed time for 'inner timer' => 1.002268 seconds $> 2022-04-19T17:32:15+00:00 [DEBUG] : Elapsed time for 'outer timer' => 2.006117 seconds
To customize the logger, you can either:
- extend the class and override the static properties or
- set the static properties at runtime.
In the following examples, we adopt the second approach.
Set the log level
By default, the logger will assume it runs in production and, therefore, will print only error-level messages.
Specify your desired log level in the following way:
Logger::$log_level = 'error'; // Show only errors Logger::$log_level = 'warning'; // Show warnings and errors Logger::$log_level = 'info'; // Show info messages, warnings and errors Logger::$log_level = 'debug'; // Show debug messages, info messages, warnings and errors
Write to file
To also write to file, set:
Logger::$write_log = true;
To customize the log file path:
Logger::$log_dir = 'logs'; Logger::$log_file_name = 'my-log'; Logger::$log_file_extension = 'log';
To overwrite the log file at every run of the script:
Logger::$log_file_append = false;
Do not print to screen
To prevent printing to STDOUT:
Logger::$print_log = false;
Parallel code caveat
The class uses the static methods and internal flags (e.g.
$logger_ready) to keep its state. We do this to make the class work straight away, without any previous configuration or the need to instantiate it. This however can create race conditions if you are executing parallel code. Please let us know if this is a problem for you, if we receive enough feedback, we will switch to a more class-like approach.
Feel free to fork the repository and make a pull request!
Before sending the request, please make sure your code passes all the tests:
composer run test