table_dump(): One of my favourite PHP debug functions.

table_dump.php

<?php

/** Number of spaces to leave between columns. */
define('TABLE_DUMP_COLUMN_PADDING', 3);

/** Maximum number of chars in a column. Longer values will be trucnated. */
define('TABLE_DUMP_COLUMN_MAX_LENGTH', 50);

/**
 * Takes an array of arrays, such as table data from a database and 
 * prints it nicely. For example:
 * 
 * tax_id     caption_id   valid_from     valid_to   percentage   
 * ============================================================
 *      5   tax.pdv.full                2009-07-31    22.000000   
 *      6   tax.pdv.full   2009-08-01   2012-02-29    23.000000   
 *      7   tax.pdv.full   2012-03-01                 25.000000   
 *      8       tax.zero                               0.000000
 * 
 * 
 * If using non-ascii characters, make sure to set mb_internal_encoding
 * to the appropreiate value, e.g.:
 * <pre>mb_internal_encoding('UTF-8');</pre>
 * 
 * @param array $array Input array.
 * @param array $return If set to true, the dump will be returned as string 
 *   	instead of printing it. 
 */
function table_dump($array, $return = false)
{
	if (!is_array($array)) 
	{
		trigger_error("Invalid input for table dump. Not an array.", E_USER_WARNING);
		return false;
	}
	
	if (empty($array)) 
	{
		trigger_error("Invalid input for table dump. Empty array.", E_USER_WARNING);
		return false;
	}

	// The output buffer
	$output = "";
	
	// Check input data
	foreach($array as &$row)
	{
		// Convert classes to rows
		if ($row instanceof stdClass)
			$row = (array) $row;
		
		if (!is_array($row)) 
		{
			trigger_error("Invalid input for table dump. Not an array of arrays.", E_USER_WARNING);
			return false;
		}
	}
	unset($row);
	
	$lengths = array();
	$titles = array();
	
	// Get titles from first row keys
	$titles = array_keys(reset($array));

	// Trim and record title lengths
	foreach($titles as $key => &$value)
	{
		$value = trim($value);
		$lengths[$key] = mb_strlen($value);
	}
	unset($value);

	// Process each row
	foreach($array as &$row)
	{
		$key = 0;
		
		// Record data lengths
		foreach($row as &$value)
		{
			$value = __table_dump_get_val($value);
			
			if (!isset($lengths[$key])) 
				$lengths[$key] = 0;
			
			if (mb_strlen($value) > $lengths[$key])
				$lengths[$key] = mb_strlen($value);
			
			$key++;
		}
	}
	unset($row, $value);

	// Original solution used vsprintf() instead of padding manually, but that
	// function does not work well with unicode.
	
	// Determine total row length
	$totalLength = 0;
	foreach($lengths as $len)
	{
		$totalLength += $len;
	}

	// Account for padding between columns
	$totalLength += TABLE_DUMP_COLUMN_PADDING * (count($lengths) - 1);
	
	// Print the titles
	foreach($titles as $key => $value)
	{
		$output .= __table_dump_strpad($value, $lengths[$key]);
		$output .= str_repeat(" ", TABLE_DUMP_COLUMN_PADDING); // Padding
	}
	$output .= PHP_EOL;
	
	// Print the line under titles
	$output .= str_repeat("=", $totalLength) . PHP_EOL;

	// Print the rows
	foreach($array as $row)
	{
		foreach(array_values($row) as $key => $value)
		{
			$output .= __table_dump_strpad($value, $lengths[$key]);
			$output .= str_repeat(" ", TABLE_DUMP_COLUMN_PADDING); // Padding
		}
		$output .= PHP_EOL;
	}
	
	if ($return) { 
		return $output;
	}
	
	echo $output;
}