# Logging

To record your outgoing requests and responses for debugging and historical purposes, you can use the Fansipan logger plugin that takes advantage of PSR-3 loggers.

# Installation

You may use Composer to install package

composer require fansipan/logger-plugin

# Usage

Once the plugin has been installed, you may use the Logger middleware to setup the plugin:

use Fansipan\Contracts\ConnectorInterface;
use Fansipan\Log\Logger;
use Fansipan\Traits\ConnectorTrait;

final class Connector implements ConnectorInterface
{
    use ConnectorTrait;

    protected function defaultMiddleware(): array
    {
        return [
            /** @var \Psr\Log\LoggerInterface $logger */
            new Logger($logger),
        ];
    }
}

use Fansipan\Log\Logger;

/** @var \Psr\Log\LoggerInterface $logger */
$connector->middleware()->push(new Logger($logger));

# Using a Custom Error Message

You can customize the log message by passing a second argument to the Logger constructor. This argument accepts an implementation of MessageFormatter:

use Fansipan\Log\HttpMessageFormatter;
use Fansipan\Log\Logger;

/** @var \Psr\Log\LoggerInterface $logger */
$connector->middleware()->push(new Logger($logger, new HttpMessageFormatter()));

The built-in HttpMessageFormatter allows you to set any template you want. By default, it uses the DEBUG template, which contains placeholders that will be replaced with actual values.

public const CLF = '{hostname} {req.header_User-Agent} - [{date_common_log}] "{method} {target} HTTP/{version}" {code} {res.header_Content-Length}';
public const DEBUG = ">>>>>>>>\n{request}\n<<<<<<<<\n{response}\n--------\n{error}";
public const DEBUG_JSON = ">>>>>>>>\n{request:json}\n<<<<<<<<\n{response:json}\n--------\n{error}";
public const SHORT = '[{ts}] "{method} {target} HTTP/{version}" {code}';

use Fansipan\Log\HttpMessageFormatter;

new HttpMessageFormatter(HttpMessageFormatter::CLF);
// or using your own
new HttpMessageFormatter('{request:json} <-> {response:json}');

# Log Level

By default, successful requests and responses are recorded using info level, while client and server errors (4xx & 5xx) are recorded at the error level. You can also pass a third argument to the Logger constructor to override this behavior.

use Fansipan\Log\HttpMessageFormatter;
use Fansipan\Log\Logger;
use Psr\Log\LogLevel;

/** @var \Psr\Log\LoggerInterface $logger */
new Logger($logger, new HttpMessageFormatter(), [
    LogLevel::INFO => [200, 399],
    LogLevel::ERROR => [400, 499],
    LogLevel::CRITICAL => [500, 599],
]);

The array key must be the log level, and the value can be either an integer representing a specific HTTP status code or an array representing a range of status codes.