PHP PSR-3 Logging Integration

PSR-3 defines common logger methods and interoperable log levels.

What It Does

PSR-3 defines common logger methods and interoperable log levels. The following examples distinguish a normal use case, a boundary case and a practical application.

Requirements and Compatibility

PHP 8.x and a local test environment. Apply input validation, correct error handling and the requirements of any optional libraries.

The code focuses on the core concept. Production implementation may also need routes, validation, persistence, authorization or deployment tooling.

Example 1: Basic Behavior

Install the PSR-3 contract and a concrete logger implementation.

composer require psr/log monolog/monolog

This is a command-line example; use it in its appropriate file or shell, not in the PHP source editor.

Example 2: Another Case

Use standard PSR-3 log levels and structured context rather than concatenating opaque text.

<?php
require __DIR__ . '/vendor/autoload.php';
use Monolog\Logger;
use Monolog\Handler\StreamHandler;
$logger = new Logger('app');
$logger->pushHandler(new StreamHandler('php://stderr', Logger::INFO));
$logger->info('Order queued', ['order_id' => 42, 'request_id' => 'r-72']);

This example depends on an installed extension, third-party library or configured service and is not a standalone local test.

Practical Example: Putting It to Use

Sanitize fields before passing them to any PSR-3 logger.

<?php
$context = ["event" => "login_failure", "user_id" => 21];
unset($context["password"], $context["access_token"]);
echo json_encode($context, JSON_THROW_ON_ERROR);

Important Behavior and Edge Cases

Log contexts need careful redaction and correlation IDs; avoid leaking exception contents.

Comparison with Related Functions or Approaches

Common Beginner Mistakes

Key Takeaways

• PSR-3 defines common logger methods and interoperable log levels.
• Log contexts need careful redaction and correlation IDs; avoid leaking exception contents.
• Monolog is one widely used PSR-3 implementation.

Before adapting these examples, verify the return values, test the failure paths and confirm that your application meets its security and environment requirements.