Improved 404 reporting

[SteveBooth]

In trying to debug the problem with my bbPress implementation on my SunOS host, it became very important to know who generated the 404 errors I encountered when browsing to my bbPress home directory. Specifically, I needed to know who was reporting the 404 error (i.e. who was calling '404.php' in the selected template), and what uri was considered bad. To do this, I enhanced the 404.php module and added a single line to bb_repermalink. The simple changes greatly assisted in determining the problem.

I would submit them as an enhancement for future releases.

First, I created a GLOBALS variable as follows, in bb_repermalink:

	if ( $check != $uri && $check != str_replace(urlencode($_original_id), $_original_id, $uri) ) {
		if ( $issue_404 && rtrim( $check, " \t\n\r\0\x0B/" ) !== rtrim( $uri, " \t\n\r\0\x0B/" ) ) {
			status_header( 404 );

			$GLOBALS['bad404url'] = 'From functions.bb-core.bb_repermalink $uri: >' . $uri . '<';

			bb_load_template( '404.php' );
		} else {
			wp_redirect( $permalink );
		}
		exit;
	}

And the 404.php code was modified slightly (I'm using the default 'Kakumei' template:

<h2 id="http404"><?php _e('Page not found!'); ?></h2>

<p>
  <?php _e('I\'m sorry, but there is nothing at the URL:'); ?><br/>
  <b><?php 
    _e($GLOBALS['bad404url']);?>
  <br/></b>

  <!-- //_e('['); _e(strlen($GLOBALS['bad404url'])); _e(' bytes]'); ?><br/></b> -->
</p>

The basic intent here is to not just tell the user that there is a '404 Error', but to give him (and us) at least some hint as to who threw the error and why.

Screen shot of suggested 404 format

If done correctly, the 404 page should be less an error message, and more a way for the user to solve the problem.

Start by placing the tag cloud on the 404 page, so that there's a good chance of finding topic-based information. A search box or (better, but difficult to implement) search results can be displayed (or at the very least, the text should refer to the existence of a search box/page).

If you want that info, then add this to your bb-config.php

define( 'BB_LOG_LEVEL', BB_LOG_ALL + BB_LOG_DEBUG );
define( 'BB_LOG_TYPE', 'display' );