WordPress debug plugin

_debug.php

<?php
/*
Plugin Name		Easy Debug function
Plugin URI		https://gist.github.com/1042827
Description		Allows the use of <code>_dump( $example_var );</code> or <code>_dump( 'example_global' );</code> for debugging variables. Collects everything in a global & prints in the footer (admin & public). If you want to not print, just return, then set <code>$hook</code> to <code>false</code> when calling the function.
Author			Franz Josef Kaiser
Author URI 		https://github.com/franz-josef-kaiser
Version			0.1
Options Version 0.1
License			MIT Extended

(c) Copyright 2010-2011 by Franz Josef Kaiser

@example
	# dump $example_var into the footer
	_debug( $example_var );
@example
	# dump the content of the global $example_global into the footer
	_debug( 'example_global', 1 );
@example
	# dump $example_var and echo it directly (not into the footer)
	_debug( $example_var, 0, 0 );
@example
	# dump $example_var into the footer and var_export it
	_debug( $example_var, 0, 0, 1 );
*/

/**
 * Debug cap
 * @param (string) minimum required capability to view debug output
 */
if ( ! defined( 'OXO_DEBUG_CAP' ) )
	define( 'OXO_DEBUG_CAP', 'manage_options' );

/**
 * DebugBox status
 * @param (string) minimum required capability to view debug output
 */
if ( ! defined( 'OXO_DEBUG_BOX_STATUS' ) )
	define( 'OXO_DEBUG_BOX_STATUS', '' );

/**
 * Debug function
 * 
 * @param unknown_type $input | The variable to print
 * @param (string) $global | if set to true, outputs the value of the {$input} global - (optional) default: false
 * @param (boolean) $hook | hook or return - (optional) default: true
 * @param (boolean) $var_export | true to get var_export, false to just print_r - (optional) default: false
 * @return unknown_type $_dump
 */
function _dump( $input, $global = false, $hook = true, $var_export = false )
{
	global $_dump;
	if ( ! isset( $_dump ) )
		$_dump = '';

	$global		= (bool) $global;
	$hook		= (bool) $hook;
	$var_export	= (bool) $var_export;

	$backtrace = debug_backtrace();

	$counter = count ( $_dump );

	$output  = '<div class="meta-box-sortables">';

	$status  = OXO_DEBUG_BOX_STATUS === 'closed' ? ' closed' : '';

	$output .= '<div id="debug-'.$counter.'" class="postbox metabox-holder'.$status.'" style="margin: 10px; width: 98%;">';
	$output .= '<div title="Click to toggle" class="handlediv"><br /></div>';
	$output .= '<h3 class="hndle title widget-top">Debug ';

	$output .= '<small><em>(File) </em>';
	$output .= isset( $backtrace[0]['file'] ) ? $backtrace[0]['file'] : ' n/a ';

	$output .= '<em> (Class) </em>';
	$output .= isset( $backtrace[1]['class'] ) ? $backtrace[1]['class'] : ' n/a ';

	$output .= '<em> - (Function) </em>';
	$output .= isset( $backtrace[1]['function'] ) ? $backtrace[1]['function'] : ' n/a ';

	$output .= '<em> - (Line) </em>';
	$output .= isset( $backtrace[0]['line'] ) ? $backtrace[0]['line'] : ' n/a ';
	$output .= '</small></h3>';

	$output .= '<div class="dump inside" style="margin: 10px;"><pre>';

		if ( $var_export )
		{
			$input = var_export( $input );
		}

		$export = '';
		// standard input
		if ( ! $global )
			$export = print_r( $input, true );

		// globals
		if ( $global )
		{
			if( isset( $GLOBALS[ $input ] ) ) 
				$export = print_r( $GLOBALS[ $input ], true );
		}

		if ( empty( $export ) )
			$output .= '<em> - empty - </em>';

		$output .= clean_pre( $export );

	$output .= '</pre></div>';
	$output .= '</div></div>';

	if ( ! $hook )
		return $output;

	return $_dump .= $output;
}

/**
 * Add dump to admin & public footer
 * Only visible for users with the 'manage_options' capability
 * @return void
 */
function _do_dump()
{
	if ( ! current_user_can( OXO_DEBUG_CAP ) )
		return;

	global $_dump;
	if ( isset( $_dump ) )
		echo $_dump;
}
add_action( 'admin_footer', '_do_dump' );
add_action( 'wp_footer', '_do_dump' );
?>