Error handling, debugging and logging

This page is about how Kiwa handles errors, and how you can debug your website and store logs.

Environment
Error handling
- Custom error pages
Logging
Debugging

Environment

The behaviour of the error handling depends on the APP_ENV environment variable, which is read from the .env file (see also Environment variables):

In a development environment (dev), all errors are displayed and reported.
In a production environment (prod) or in tests (test), error reporting is disabled so no internal information leaks to the visitor. Errors are still logged.

Error handling

Kiwa registers a custom error handler on every request. It does the following things:

It logs all errors with the logger.
It stores every error in a persistent file, so errors can be inspected even after the request has been finished.
It renders a styled HTML error page for the visitor.

Custom error pages

Errors with an HTTP status code are rendered with a file named after the status code inside the html folder. The website skeleton already ships a 404.phtml, and you can create any other status page, for example 500.phtml.

If a phtml file throws an exception while being rendered, Kiwa responds with a 500 and tries to load html/500.phtml. If a page doesn't exist, Kiwa responds with a 404 and loads html/404.phtml. If no custom error page is available, a built-in error page is loaded instead.

Logging

Kiwa uses a PSR-3 compatible logger, which is accessible through the DI class:

<?php

use Kiwa\DI;

DI::getLog()->info('This is an info message.');
DI::getLog()->debug('This is a debug message.');
DI::getLog()->error('This is an error message.');

The logger writes to a file inside the var folder. All log levels of the PSR-3 standard are available: emergency(), alert(), critical(), error(), warning(), notice(), info() and debug().

In a development environment, log messages are also printed directly to the command line when using the Kiwa Console.

Debugging

The error pages and the log files are stored inside the var folder of your project. You can inspect them with the tools of your choice, for example:

$ tail -f var/log/debug.log