root/trunk/common/mvblog_debug.php

<?php
/**
 * MvBlog -- An open source no-nosense blogtool
 *
 * Copyright (C) 2005-2008, Michiel van Baak
 * Michiel van Baak <mvanbaak@users.sourceforge.net>
 *
 * See http://dev.mvblog.org for more information on MvBlog.
 * That page also provides Bugtrackers, Filereleases etc.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 *
 * @package MvBlog
 * @author Ferry Boender
 * @version 2.0
 * @copyright 2005-2008 Ferry Boender
 */

/**
 * Debugging class that takes care of error reporting, etc.
 * @package MvBlog
 */
Class MvBlog_debug {
    /**
     * @var array $development_hostnames Hostnames that will turn on strict errors.
     */
    public static $development_hostnames = array(
        "dev",
        "localhost",
        "127.0.0.1"
    );

    /**
     * @var array $error_names List of errors in int and string format.
     */
    public static $error_names = array(
        1    => "E_ERROR",
        2    => "E_WARNING",
        4    => "E_PARSE",
        8    => "E_NOTICE",
        16   => "E_CORE_ERROR",
        32   => "E_CORE_WARNING",
        64   => "E_COMPILE_ERROR",
        128  => "E_COMPILE_WARNING",
        256  => "E_USER_ERROR",
        512  => "E_USER_WARNING",
        1024 => "E_USER_NOTICE",
        2048 => "E_STRICT",
        4096 => "E_RECOVERABLE_ERROR",
        8191 => "E_ALL",
    );

    /**
     * Starts the development error reporting, which is much stricter than
     * normal. This is to ensure that developers fix errors and notices that
     * occur. This will only be set when the current hostname exists in the
     * MvBlog_debug::$development_hostnames array.
     *
     * @param bool $warn_strict (optional) Warn/stop on strict errors?
     */
    public static function start_development($warn_strict = True) {
        /* Turn on heavy error reporting so that no errors go unnoticed, but 
           only for development hostnames. This way end-users won't accidentally get
           errors they shouldn't be seeying. */
        if (
            array_key_exists("SERVER_NAME", $_SERVER) &&
            in_array($_SERVER["SERVER_NAME"], MvBlog_debug::$development_hostnames)
        ) {
            MvBlog_debug::start_pendantic_errors($warn_strict);
        }

    }
    /**
     * Starts the pendantic error logging mode. Every error will stop execution
     * of the script straight away. You can specify if you DON'T want Future
     * errors to also stop the script.
     *
     * @param bool $warn_strict (optional) Warn/stop on strict errors?
     */
    public static function start_pendantic_errors($warn_strict = True) {
        // Asserts can be used to test preconditions in, e.g. functions. They
        // are off by default. Turn them on here.
        assert_options(ASSERT_ACTIVE, 1);
        assert_options(ASSERT_WARNING, 1);
        assert_options(ASSERT_BAIL, 1);

        // Turn on the highest level of error reporting.
        if ($warn_strict && defined("E_STRICT")) {
            error_reporting(E_ALL | E_STRICT);
        } else {
            error_reporting(E_ALL);
        }

        // Show errors in the source code (to annoy developers)
        ini_set("display_errors", "1");

        // Set a custom error handler that's stricter than the normal one.
        set_error_handler(array("MvBlog_debug", "user_error_handler"));
    }

    /**
     * The MvBlog custom error handler. This error handler will does basically
     * the same as the normal error, except that it also exists on when an
     * error or notice is encountered.
     *
     * @param int $errno The php error number
     * @param string $errstr The php error message
     * @param string $errfile The php file where the error is
     * @param int $errline The line where the error is
     */
    public static function user_error_handler($errno, $errstr, $errfile, $errline) {
        $error_reporting_level = error_reporting();

        // Only show errors for which error reporting level is turned on.
        if ($error_reporting_level & $errno) {
            $errtype = MvBlog_debug::$error_names[$errno];
            echo($errtype." error in <b>".$errfile."</b>:<b>".$errline."</b> - <i>".$errstr."</i>");
            exit();
        }
    }
}