Pages - Log exceptions and errors

pages-log-exceptions-errors.php

<?php
/*
From https://github.com/joomlatools/joomlatools-pages/discussions/692

Exceptions in Pages are exposed as events, meaning that you they can be easily intercepted them through event subscribers. This allows for a whole lot of flexibility. Based on the type of exception different event handlers could do different things, for example;

handling 404 not found exceptions
handling error logging
rendering debug information
Basic exception event subscriber
This is an example of a custom exception handler you can add to your own site. Add it to: /joomlatools-pages/extensions/pages/event/subscriber/exception.php
*/

class ExtPagesEventSubscriberException extends ComPagesEventSubscriberAbstract
{
    public function onException(KEvent $event)
    {
        $exception = $event->exception;

        if($exception->getCode() == 500)
        {
             //Handle exception here
        }
    }
}

/*
Exception logger using Monolog
This is an example of a Monolog exception logger you can add to your own site. Add it to: /joomlatools-pages/extensions/pages/event/subscriber/error.php

Object properties:
enabled: An event subscriber has an enabled property to to allow you to disable it dynamically, by default a subscriber is enabled. Here i'm disabling it if debug is off. If you want to always enable it, take out this code.
base_path: Using the pages logs path to store the error logs
*/

use Monolog\Logger;
use Monolog\Handler\StreamHandler;
use Monolog\Processor\WebProcessor;
use Monolog\Formatter\LineFormatter;

class ExtPagesEventSubscriberError extends ComPagesEventSubscriberAbstract
{
    protected function _initialize(KObjectConfig $config)
    {
        $config->append([
            'enabled'    => JDEBUG ? true : false,
            'base_path'  => $this->getObject('com:pages.config')->getSitePath('logs'),
        ]);

        parent::_initialize($config);
    }

    public function getFile()
    {
        return $this->getConfig()->base_path.'/'.'error.log';
    }

    //https://chrishewett.com/blog/monolog-human-readable-exception-email-with-stack-trace/
    //http://www.inanzzz.com/index.php/post/xj81/handling-and-logging-exceptions-in-symfony-api-applications
    public function onException(KEvent $event)
    {
        if(class_exists('Monolog\Logger'))
        {
            $exception = $event->exception;

            if($exception->getCode() >= 500)
            {
                //Log invalid requests exception
                $file = $this->getFile();

                // Create a logger
                $logger  = new Logger('error');
                $handler = new StreamHandler($file);
                $handler->setFormatter(new PrintRLineFormatter());

                $logger->pushHandler($handler);
                $logger->pushProcessor(new WebProcessor());
                $logger->pushProcessor(function ($record)
                {
                    if( !empty( $_SERVER ) ){
                        $record['extra']['_SERVER'] = $_SERVER;
                    }
                    if( !empty( $_SESSION ) ){
                        $record['extra']['_SESSION'] = $_SESSION;
                    }
                    if( !empty( $_POST ) ){
                        $record['extra']['_POST'] = $_POST;
                    }
                    return $record;

                });

                $log = [
                    'code' => $exception->getCode(),
                    'message' => $exception->getMessage(),
                    'file' => $exception->getFile(),
                    'line' => $exception->getLine(),
                ];

                if ($exception->getPrevious() instanceof Exception)
                {
                    $log += [
                        'previous' => [
                            'message' => $exception->getPrevious()->getMessage(),
                            'exception' => get_class($exception->getPrevious()),
                            'file' => $exception->getPrevious()->getFile(),
                            'line' => $exception->getPrevious()->getLine(),
                        ],
                    ];
                }

                $logger->error($exception->getMessage(), $log);
            }
        }
    }
}

class PrintrLineFormatter extends LineFormatter
{
    public function format(array $record)
    {
        return print_r( $record, true );
    }
}