Converts to JSON, in a pretty, human readable format (yet still valid JSON).

prettyJSON.php

<?php

/**
 * Converts to JSON, in a 'pretty', human readable format (yet still 
 * valid JSON).
 *
 * This code was modified from this GitHub 
 * <a href="https://gist.github.com/GloryFish/1045396">Gist</a>.
 *
 * @param string $json The JSON code to prettify.
 */
function prettyJSON($json) {

	// parser state
	$tabcount = 0;
	$result = '';
	$inquote = false;
	$ignorenext = false;

	// parse JSON, generating the reformatted output
	for($i = 0; $i < strlen($json); $i++) {
		$char = $json[$i];

		if ($ignorenext) {
			
			$result .= $char;
			$ignorenext = false;
		
			// skip parsing of char (in switch below)
			continue;
			
		}
		
		switch($char) {
			
			case ':':
				$result .= $char . (!$inquote ? " " : "");
				break;
				
			case '{':
				if (!$inquote) {
					$tabcount++;
					$result .= "$char\n" . str_repeat("\t", $tabcount);
				} else {
					$result .= $char;
				}
				break;
				
			case '}':
				if (!$inquote) {
					$tabcount--;
					$result = trim($result) . "\n" . str_repeat("\t", $tabcount) . $char;
				} else {
					$result .= $char;
				}
				break;
				
			case ',':
				if (!$inquote) {
					$result .= "$char\n" . str_repeat("\t", $tabcount);
				} else {
					$result .= $char;
				}
				break;
				
			case '"':
				$inquote = !$inquote;
				$result .= $char;
				break;
				
			case '\\':
				if ($inquote) $ignorenext = true;
				$result .= $char;
				break;
				
			default:
				$result .= $char;
			
		}
		
	}

	return $result;
	
}

?>