README

Overview

This package provides global functions for logging and de-couples from any and all PSR-3 implementations. Instead of storing or injecting a PSR-3 logger interface in each class where logging functionality is needed, the Logger is stored in a global, single instance object that can be configured at startup/bootstrap globally.

The global functions can be called by any function or class member (including static class members). If configured, the globally configured logger is used, otherwise the native php error_log() function is used.

For more about PSR-3, see https://www.php-fig.org/psr/psr-3/

Installation

composer require sterlingdesign/global-logging

The installation includes a test file so that you can verify the installation and also experiment with operation and configuration. The script is meant to be run from the command line, for example:

php -f vendor/sterlingdesign/global-logging/test/test-global-logging-cli.php

Log Target Configuration

In the simplest case, the Log functions (see Global Functions below) can be used without configuring any PSR-3 log target. If a PSR-3 logger has not been configured, the built-in PHP function error_log($message, 0) is used to send the message to PHP's system logger (see https://www.php.net/manual/en/function.error-log).

NOTE: all LogXXXX calls are sent ONLY to the php system log unless you configure another PSR-3 Logger (see below). If your application requires Email or SMS notification of critical errors, configure one of the many logger's available with that capability, such as monolog

If your application uses a PSR-3 compliant logging facility, such as 'monolog', you can create an instance of that logger and set that object as the global target. If a PSR-3 logger has been configured, that logger is used by all LogXXXX functions instead of the native PHP error_log() function.

your_bootstrap_file.php

<?php

use Sterling\LogTarget;
use Psr\Log\LogLevel;

if(class_exists('\\Monolog\\Logger') && class_exists('\\Monolog\\Handler\\StreamHandler'))
    {
    // If Using a PSR-3 Logger, configure it and tell LogTarget to use it:
    $log = new \Monolog\Logger('name');
    $log->pushHandler(new \Monolog\Handler\StreamHandler(__DIR__ . '/testing_monolog.log', Logger::WARNING));
    LogTarget::getInstance()->setLogger($log);
    }
else
    {
    // The following option only applies if you are not using a logger:  
    // If you don't have a way to send debug logs back to the client, 
    // you may want to write all LogXXXX calls to the PHP system log.
    // CAUTION: This could potentially result in large amounts of log data
    LogTarget::getInstance()->setIgnoreLogLevels([]);
    // Or, maybe you would like to ignore all log calls below Warning
    // to reduce the amount of data written to the PHP system log:
    LogTarget::getInstance()->setIgnoreLogLevels([LogLevel::NOTICE, LogLevel::INFO, LogLevel::DEBUG]);
    }

// - Configure other LogTarget Options:    
// enable automatic context generation for all LogLevels for more detail:
LogTarget::getInstance()->setAutomaticContextGenerationLevels(LogTarget::ALL_LEVELS);
// disable storing log calls in memory if you don't need to look at them or your PSR-3 logger already does this
LogTarget::getInstance()->setStoreInMemory(false);

some_application_file.php

// add records to the log: These functions are supplied by this package:
LogWarning('Foo');
LogError('Bar');
LogDebug("Testing!");

For a working example, see the included test script that should be installed at vendor\sterlingdesign\global-logging\test\test-global-logging-cli.php

Global Functions

These functions are supplied by this package and are loaded by the autoloader into the top-level, global, namespace.

LogEmergency(mixed $item, array $context = array());

LogAlert(mixed $item, array $context = array());

LogCritical(mixed $item, array $context = array());

LogError(mixed $item, array $context = array());

LogWarning(mixed $item, array $context = array());

LogNotice(mixed $item, array $context = array());

LogInfo(mixed $item, array $context = array());

LogDebug(mixed $item, array $context = array());

LogAtLevel($level, mixed $item, array $context = array());

// For LogAtLevel, the $level parameter should be one of the \Psr\Log\LogLevel constants.
// If it is not one of the defined values, logging will default 
// to \Psr\Log\LogLevel::ERROR

The global functions are simple wrappers for calling the LogAtLevel function on the global, single instance of \Sterling\LogTarget. One could also use the LogTarget directly, for example:

\Sterling\LogTarget::getInstance()->LogAtLevel(\Psr\Log\LogLevel::DEBUG, "Testing!", []);

Additional Functionality

In-Memory Log Store

In addition to forwarding LogXXXX function calls to a PSR-3 Logger (if configured) or php log (if no PSR-3 Logger is configured), the LogTarget class also stores the current requests' Log call Information in an in-memory array. This is useful for dumping current request log info back to the client when debugging.

By default, each call to the LogXXXX functions for the current request is stored in an array of arrays. For example, to get the array of stored Log calls, you could do the following:

require_once "path/to/your/autoload.php";
// Optionally configure any Psr\Log\LoggerInterface you are using
// \Sterling\LogTarget::getInstance()->setLogger($oMyLogger);

LogDebug("Testing!");
echo \Sterling\LogTarget::getInstance()->getLogFormatted();

If one of your log handlers already has this functionality, you can disable the Sterling\LogTarget store in memory by calling

\Sterling\LogTarget::getInstance()->setStoreInMemory(false);

Or you may wish to disable/enable In-Memory storage of Log calls Dynamically depending on if you are debugging or not:

\Sterling\LogTarget::getInstance()->setStoreInMemory(IsDebug());

Automatic Context Generation

The PSR-3 standard provides for supplying a context to the Logger::log functions. These contexts can be automatically generated in the form of a debug_backtrace if not explicitly supplied to the LogXXXX functions.

You can control which LogLevel's, if any, get automatically generated backtraces using the LogTarget::setAutomaticContextGenerationLevels() function. The argument should be an array specifying which LogLevels should have contexts generated automatically. To disable automatic context generation, pass an empty array.

Roadmap

The current implementation provides a basic php log file output without any further work. In the future, depending on demand, it would be possible to add formatting functionality so that when there are no PSR-3 Logger objects, the php log file output can be customized.

The immediate goal is to correct any glaring errors in the existing implementation, then maintain the package for compatibility with the PSR-3 standard and also compatibility with the native php function error_log.

Breaking changes are possible if anyone suggests a good idea, and would be introduced in a future major version release.

Contributions are welcome.